Megacolon - The curse of the 33 spots [Updated on: 11/26/17 01:17]
This page is a mishmash - hodgepodge of information on Megacolon and the En spotting breeds. The page is semi-organized . It is meant for storage of information only.


This page is dedicated to Racer, Beau Binky, and Horatio Binky.

Racer is an English (Spot) breed of rabbit. Unfortunately he inherited two En genes. Here he is wanting pets @ an EBBR adoption event. On December 21st, 2013 my 3+ month petting buddy was adopted. I Hope he does really well with his new family.

Racer passed away on June 19th, 2014. His adopter went away on a vacation leaving him to be watched. It is extremely critical that a MC rabbit be cared for by a rabbit savvy person that knows them best, as they will know what signs to look for with Megacolon. Rest in peace Racer.

Beau Binky & Horatio Binky

When I put this page online and really started looking for Megacolon information I ran across the facebook Megacolon Bunnies group. When I joined, Clint Dinkums' (OP for group), rabbit Beau passed away a few months after this. Then Horatio got sick and passed, both were MC rabbits. Both did not pass from megacolon as she managed it for many, many years. Both passed away at almost exactly the same age.

She is a execellent source of information on Megacolon, medicine, and many thigns dealing with rabbits. She has answered all of my questions and is always willing to help. Megacolon is difficult in that each rabbit is different and responds differently to treatment. Thanks Clint for all your help and answering all my questions! :)

My new petting buddy. Clover is a Rex mix that has "pre" megacolon at the rescue I help at. She has been there for a number of months and they are trying to find her the right diet and medication mix. She reminds me a lot of Racer and is also very sweet.

Newer Megacolon webpages..

This information is for reference only! See a rabbit savvy Vet if you need help with your rabbit!

        Below is the information I have gathered on Megacolon and other information that surrounds it. This page is loosely organized (mishmash mess.) All information & media is linked back to the orginal source. This is where I store and reference the information I have found. I hope it can help others.

Megacolon - The curse of the 33 spots
  • "A change in breeders' attitude and breeding practices is mandatory because neither the permanent elimination of animals not "fitting" a fancy standard nor the continuous production of defective genotypes is legal." - Gerlitz S., Wessel G., Wieberneit D., & Wegner W.

Please Rembember: "Each megacolon bunny has to be treated very much as an individual and it's a matter of trial and error to find the right balance for that bunny." - Clint Dinkums; OP for Megacolon Bunnies on Facebook

"Megacolon is believed to be caused by an improper development or malfunction of the colon/cecum. Rabbits with this disorder have trouble extracting essential nutrients from food, may not produce cecotropes and frequently have trouble maintaining weight. It is suspected that there may be may be a number of different disorders that are lumped into this category because of similar symtpoms ; this would explain why treatments that help one individual may actually worsen the condition of the other."- Quote comes from a post on; referencing source When Your Rabbit Needs Special Care: Traditional and Alternative Healing Methods, Lucille C. Moore, Kathy Smith, Web.

  • Best source for online help, information and resources for MC are:

    • Some vets do not belive that Megacolon is a real 'syndrome.' The Megacolon group on facebook has a list of vets that know about Megacolon.
    • PLEASE NOTE: Some of the information (text and pictures) on this page comes from breeders or medical research papers. This can include necropsy (autopsy) pictures. This may upset some.
    • This pages focuses on the English 'Spot' (as this is what Racer was), Checkered Giant, and other breeds with the En/En genes. If you find anything that is wrong, outdated or you know of updated information, on MC/CPS, that can help others please email me.

"Pre-Megacolon": Some vets may refer to a rabbit as pre-megacolon. They will have the 'correct' fur/coat phenotype (genetic characteristics you can see, i.e. limited/light color markings), oval poops, along with having minor GI issues.

"Mechanical" Megacolon: Sometimes a rabbit can get the same symptoms as a genetic En/En rabbit but through "mechanical" means such as spinal fracture or other traumatic events. An example would be the loss of mobility in the hind legs that could causes MC like symptoms. Some rabbits can also "acquire" the same problems which basically is as a result of surgery interfering with the nerves that regulate the gut. it cant be helped sometimes and is a post op complication

"Acquired" Megacolon: Some rabbits can also "acquire" the same problems from a spay or other types of surgery. This is the consequence of the effects from the surgery obstructing nerves that regulate the gut. These normally show up post-op.

Markings to look for on a possible megacolon rabbit
  • Spots
  • Eye markings
  • Broken spine marking
  • Broken nose butterfly
  • Tend to all help identify and En/En gene mc bunny
  • - Clint Dinkums; OP for Megacolon Bunnies on Facebook

Breed's that can get two En genes and possibly megacolon:

        "The dominant English white spotting gene, En, gets its name from the English Spot breed. The same gene is found in the Checkered Giant, Blanc De Hotot, Lop, Rex, Satin, and Rhinelander breeds and their varieties. " - Rabbit Production By Steven D. Lukefahr, Peter Robert Cheeke, Nephi M. Patton, 2013, Page 209, Web.

Albino rabbits that are homozygous for the 'English Spot' gene (have the En/En genes.)

Recent responce from the House Rabbit Society on MC:
        squidpop posted a question on [June 4th, 2014] about Megacolon and also emailed the HRS. (S)he got a responce from Dana Krempels, Ph.D., Senior Lecturer, Director of Undergraduate Studies, University of Miami Department of Biology and Houserabbit Adoption Rescue and Education Rabbit Rescue director. Below is her responce:

        "Not all "charlies" have the congenital failure of their melanocyte neuron-precursor cells to properly migrate and innervate the gut. It's a polygenic condition, and also possibly influenced by in utero environment. In short, the actual developmental mechanism isn't fully understood. I would say the vast majority of "charlie" rabbits do NOT have the condition, though. It's not all that common. But it's awful when it does show up."

  • charlies - a rabbit with very little color marking patterns (some say 10% or less), in this case it's a rabbit that is homozygous (En/En). Some rabbits are refered to as a 'false' charlie, they look like an En/En rabbit, but are heterozygous (En/en) and will not have MC.
  • congenital - especially of a disease or physical abnormality present from birth
  • melanocyte - melanin-producing cells located in the bottom layer of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, meninges, bones, and heart. Melanin is the pigment primarily responsible for skin color
  • neuron - a specialized cell transmitting nerve impulses; a nerve cell
  • innervate - to supply (an organ or other body part) with nerves
  • polygenic - of, relating to, or determined by polygenes -> a gene whose individual effect on a phenotype is too small to be observed, but which can act together with others to produce observable variation

Anne Martin, the Executive Director over at House Rabbit Society in Richmond, posted (on fb's MC group on Sep 23rd, 2014) about her MC foster rabbit Marie and her special diet:

"Marie's on a special diet from Dr. Sari Kanfer's protocol - she's down in San Diego, but she shared her protocol with other vets on VIN." She gets a mixture, BID ("bis in die"-Latin for twice a day) of:
  • Pumpkin
  • Soy protein powder (you can get at Trader Joes)
  • Critical Care
  • Water
"The soy protein powder completely reversed her wasting along her spine & helped her to gain all her weight back. Let me know if you want the proportions I've used." - Currently she has not posted back the proportions yet.

PLEASE NOTE: Before trying anything with a MC rabbit you will need to consult a rabbit savvy vet!

NOTE: In 2010 Dr. Sari Kanfer, DVM created the Exotic Animal Care Center in Pasadena, CA. You can see her interviewed here.

  • This syndrome is mostly refered to as Megacolon (MC). Other terms it has been called in the past:
    • Congenital Megacolon
    • Cowpile Syndrome (CPS)
    • Congenital Agangliosis
    • Cow Poop Syndrome

  • Some of the consequences & info of inheriting two En genes from Megacolon studies:
    Solids (en/en)= kk, Spotted (En/en) = Kk, Charlies (En/En) = KK
    • "A change in breeders' attitude and breeding practices is mandatory because neither the permanent elimination of animals not "fitting" a fancy standard nor the continuous production of defective genotypes is legal."
    • "A significantly augmented intestine (abs. and rel.) in KK-animals, specially with reference to the gross intestine--indicating a tendency to motility disturbances and/or chronic obstipation."
    • "Additional findings support the conclusion, that there is a very distinct predisposition of homozygous KK animals to develop megacolon with growing age. This also has consequences for the relative organ weight of the heart and of the adrenals in this genotype."
    • "Significance of lower heart weights was stated in DRS-KK-animals," [Giant German Spot Breed] "probably induced by minor activities observed in this genotype."
    • "Gender influences varied hormonal characteristics and disease manifestations too: A dramatic fall in severely diseased does with respect to T3-concentration as well as a seemingly more inactive thyroid gland compared to bucks underline hormonal influences."
    • " It was found that En/En rabbits showed significantly reduced sodium absorption rates across the wall of the cecum. Consequently, the dry matter content of the ingesta was reduced at this location, whereas the content of the ashes was increased. These results indicate that a further important pathogenetic aspect of this hereditary disease is an undue liquification of ingesta in proximal parts of the large intestine."
    • "Thus, there are some indications that an early site of spot-gene related effects might be the small intestine. This segment of the bowel was shorter and had an increased dry matter proportion of its wall when compared with heterozygous spotted rabbits. But a decreased proportion of dry matter within the wall of the large intestine was found. The latter could be an effect of the hypothyreotic state of metabolism in En/En rabbits."

"Having the appearance does not mean they will develop issues. It's a risk factor, but not a certainty. Some rabbits are Charlies and don't ever have issues. Other rabbits are fine until they hit a major stressor (usually) and suddenly they have digestive issues. Once symptoms appear, there is no known way to revert to "normal" again." - Joanna Campbell of the Minnesota Companion Rabbit Society (MCRS), founder and president; quote from When Your Rabbit Needs Special Care: Traditional and Alternative Healing Methods, Lucille C. Moore, Kathy Smith - P. 97, Web.

"In several rabbit breeds a spotting pattern is caused by the incompletely dominant "English Spot" - gene (En) which has recently found by this research group to be associated with a inherited predisposition for a malady from Megacolon-Syndrome..." - World Rabbit Science 1995, 3(1), p. 19-26, Wieberneit D., Wegner W.

"Sadly, the condition is congenital, and there really is no cure. The best you can hope to do is to provide palliative care", relieving pain or alleviating a problem without dealing with the underlying cause, "and diet that will not exacerbate the condition. But some individuals seem to have it worse than others, are more prone to intestinal (not stomach) blockagest because of it, and at some point when they develop a very serious conditionk, it sometimes cannot be reversed." - Dana Krempels, Ph.D.- 3/5/2006, Web Post

With "normal" English Spot kits (and some other breeds), the Chariles (25% of the litter with partial markings) will have the En/En color 'spotting' gene. This is the incompletely dominant "English Spot" gene [En]. Getting two of these genes is linked with the inherited predisposition for Megacolon syndrome. "The disorder is believed to be caused by a misdevelopment or malfunction of the colon and/or cecum." - Kathy Smith,
Rabbit Health in the 21st Century: A Guide for Bunny Parents - P. 46, Web. Buy the EBook here. Not all charlies will be affected by Megacolon, they just have a "predisposition" for it. There is a wide range on how the syndrome could affect a rabbit.

  • Marked English Spot bred with Marked English Spot will have:
  • Charile - 25% of the litter with partial markings (Nose, Ears & Eye rings) [This is the one with the En/En genes]
  • Sport/Self- 25% of the litter with a solid color [Has en/en genes]
  • Marked/Broken - 50% have "all" the markings [Has En/en genes]

The En and en genes are the English spotting genes (aka English spotting coat color locus or Dominant white spotting locus). The rabbit only needs to inherit one En gene, from its mother or father (En/en or En/En), to have spots in its coat because it's the dominant gene. If the rabbit inherits two en genes then it will be a solid color with no white. The dominant gene is the trait that you can 'see'. The phenotype is all the 'observable' genes that the rabbit inherits. The genotype is all the dominant and recessive genes that the rabbit carries. Rabbits that inherit two En genes can possibly have a predisposition for Megacolon.

Parent #1 Parent #2 Kits
Charlies (En/En) Broken (En/en) Solid (en/en)
Charlie Charlie 100% 0% 0%
Broken Charlie 50% 50% 0%
Broken Broken 25% 50% 25%
Solid Broken 0% 50% 50%
Solid Charlie 0% 100% 0%
Solid Solid 0% 0% 100%

[Overview | English Spot Breed | En/en Genes | MC/CPS Background | Care | Reference & Research | Poop | What is Megacolon?]

What is Megacolon? By mossbinky (a group moderator on Bunny Lovers Unite) on Flickr

Can a normal rabbit have MC looking poops? Can a MC rabbit have normal looking poops one day and MC poops the next?

"Fluctuation is a difficult question. Generally in En/En megacolon bunnies they stay the same. They may go *too small* if the bunny is dehydrated or in a crisis, or turn to mushy slop in bloat as it comes out. Bbut if in good health (for them) then they should stay the same.

However, if you've got a normal bunny fluctuating between what look like mc poops and normal poops then that can be because of numerous things: meds, moult, hydration, stress - I've seen non mc bunnies produce huge poops when ill and then return to normal size when their health stabilises. So i would say generally TRUE genetic megacolon bunnies will always stay the same (if well) and non mc's will or can fluctuate and give off "faux" megacolon symptoms poop-wise." - Clint Dinkums MB Op.

The following poop pictures are from here. See the Bunny Lovers Unite MC poop webpage for many more pics!

Left to right: "normal (perhaps slighly dehydrated) small FECAL poop from small bunny, then normal round poop from bigger bunny, then megacolon poop from same sized bunny."

"photo of absolutely classic megacolon FECALS which are generally very large, and OVAL or torpedo shaped, rugby ball shaped."

"a classic megacolon CECAL. long, fat, sausagey, strong smelling, non shiny, LARGE segments. nothing like the healthy 'bunch of grapes' type of cecals in normal bunnies."

"really good comparison photo between megacolon fecals (left) and normal fecals (right). although the mc fecals are irregular because of moult (see the fur strings) the size difference is very clear."
This information is for reference & research only! See a rabbit savvy Vet if you need help with your rabbit!

** The text below, by By mossbinky, is located here on Flickr in the on Bunny Lovers Unite group. **

Introduction by jojo79: "This thread will explain what Megacolon is including symptoms and possible treatments. This advice is NOT a substitute for Veterinary advice. please always consult your Vet!"

        There are a lot of other possibilities to rule out before megacolon is diagnosed, but we can help with those too. So take the time to read through this article from medirabbit if you think your bunny may suffer from megacolon. Medirabbit on megacolon and its differential diagnoses (ie what it could be, if it's not megacolon): Differential diagnosis for megacolon in rabbits on MediRabbit.

       An older scientific study from 1995 but still relevant. Quite technical: Research Paper "Pathophysiological and functional aspects of the megacolon-syndrome of homozygous spotted rabbits." by Bodeker D, Turck O, Loven E, Wieberneit D, Wegner W. from Institute of Animal Breeding and Genetics, Hannover School of Veterinary Science, Germany., Zentralbl Veterinarmed A. 1995 Nov;42(9):549-59. [Abstract]; Medical research paper.

       It's very important to check for other things like coccidia or dietary issues before going on to fully diagnose megacolon. However even these are frequently overlooked by vets and we've had some successes picking up missed coccidia and being able to recommend and suggest treatment for these bunnies, whose guts have then normalised and they've not been megacolon bunnies at all! other successes have included dietary adjustments which again have normalised poops that have been troublesome for a long, long time.

       Both these things are fabulous because it's great to find out that your bunny is not megacolon and his condition is reversible.

       However, mc bunnies themselves *are* prone to repeated gut infections and strong reactions to certain food types, so it's possible to have for example, coccidia and mc, or be eating an unhelpful diet - and be a megacolon bunny.

       So bring your suspicions of mega colon and/or long term gut issues here for support, advice and help, for both you and your veterinarian.        We have also noted that the great majority of the bunnies we've encountered on our facebook group so far (50 members) with diagnosed mc are MALE. This is apparently true of cats with mc too. Predominately male! So again are genes playing a part?

       Megacolon bunnies often dont live past the age of 5. In fact the majority are thought to die much younger with the condition going completely undetected and undiagnosed and they usually simply die from classic rabbit problems diagnosed as 'stasis' or 'bloat' 'anorexia' or more rarely undetected gut infections. Because their immune systems dont seem to work as well as non mc bunnies, this also means they can more easily fall prey to opportunistic illnesses like e.cuniculi or mites/pasturella etc. These in turn can be more serious for them, often with recurring bouts (or fatality) despite treatment.

       Megacolon bunnies can have very varied nutritional needs and their diets often require extra protein, or extra green foods to help with motility. This is thought to do with the way their guts use the food that they eat. So each megacolon bunny has to be treated very much as an individual and it's a matter of trial and error to find the right balance for that bunny. Also it can vary as they age. Beau for example has had to have a much 'wetter' (more greens etc) diet after the age of 4 when his gut began to really slow down.

       So what is megacolon? Why would you suspect it?

       The FECALS of a mega colon bunny will tend to be significantly bigger than a normal bunny's poops. also they are usually oval in shape (rugby ball shaped) rather than round.

       The CECOTROPHS of a mega colon bunny are very different from the classic 'bunch of grapes' tiny small shiny segments all clumped together in a normal bunny, which can smell pleasantly 'fruity'. MC cecotrophs can be literally huge. They tend to present as a long sausage/torpedo shaped thing (up to an inch long is common) and the segments within them are much larger than the tiny bunch of grapes ones. It is generally not as shiny either (healthy mucous). It often has a tarry appearance and they smell much stronger than normal cecos and rather unpleasant, almost like a carnivore's poops.

       Photos are on the following link page here.

[Overview | English Spot Breed | En/en Genes | MC/CPS Background | Care | Reference & Research | What is Megacolon?]

Mega-colon / CPS - Background Information


Lop charlie image from here.

Image from onthebrightsiderabbitry
"Congenital agangliosis or "cowpile syndrome or "megacolon" is believed to be caused by an improper development or malfunction of the colon/cecum. Rabbits with this disorder have trouble extracting essential nutrients from food, may not produce cecotropes and frequently have trouble maintaining weight. It is suspected that there may be may be a number of different disorders that are lumped into this category because of similar symtpoms ; this would explain why treatments that help one individual may actually worsen the condition of the other." - Quote comes from a post from; referencing source When Your Rabbit Needs Special Care: Traditional and Alternative Healing Methods, Lucille C. Moore, Kathy Smith, Web.

"The symptoms of this disorder include big misshapen soft fecal pellets, frequently covered with mucus and a drippy bottom alternating with long painful bouts of GI stasis. During the spells of stasis it may be possible to feel large masses of fecal matter similar in consistency to ropes of play dough. This condition is always episodic in nature characterized by flare-ups followed by period of relative improvement. There is little agreement among vets, experts and caregivers about what diet or medication works best in these cases. Many caregivers have found that rabbits with this condition do not tolerate greens well... however this may not be true for your rabbit-listen to whatever his body tells you. Because rabbits with this condition often need extra nutritional support eliminating pellets may no be a good idea. Several caregivers have reported that better tolerance with extruded food (such as Kaytee exact Rainbow) than for either alfalfa or timothy pellets." - Quote comes from a post from; referencing source When Your Rabbit Needs Special Care: Traditional and Alternative Healing Methods, Lucille C. Moore, Kathy Smith, Web.

"Congenital Agangliosis, also known as "Mega-colon" or "Cow Pile Syndrome" is a hereditary disorder of the gastrointestinal tract found in some rabbits with the "English Spot" or En/En color gene. These rabbits are generally white with dark black or brown rings around their eyes and black or brown spots on their back. The symptoms of the disorder include big, misshapen, soft fecals, frequently covered with mucous, and a drippy bottom alternating with long, painful bouts of GI slowdown or stasis. The disorder is believed to be caused by a misdevelopment or malfunction of the colon and/or cecum. During the spells of stasis, it is possible to feel large masses of fecal material with the consistency of ropes of play dough when the rabbit's belly is palpated. Before arriving at this diagnosis, fecal tests are recommended to eliminate the possibility of parasites or a bacterial imbalance or overgrowth in the GI tract. Rabbits with this disorder have trouble extracting essential nutrients from food, may not produce cecals, and frequently have difficulty maintaining weight. Some rabbits experience recurrent attacks of severe GI stasis. This condition is nearly always "episodic" in nature, characterized by flare-ups followed by periods of relative improvement." - Kathy Smith, Rabbit Health in the 21st Century: A Guide for Bunny Parents - P. 46, Web. Buy the EBook here

Note: Orginal text is in italian. "The megacolon (congenital agangliosi) and 'a hereditary disorder of the GI tract, more' common in rabbits with the gene En/En, that 'what gives the characteristics of the mantle Hotot, Inglese Spot, etc.. ie, white with black or brown spots around the eyes and / or back. It is an abnormal accumulation of feces in the intestines, which can not be expelled: Symptoms include feces huge, malformed, thick mucous, you may have frequent episodes of diarrhea or loss of mucus alternating with moments of intestinal stasis. The rabbits with this problem have difficulty 'to assimilate the nutrients from food, sometimes they do not produce ciecotrofi and often have problems of excessive thinness. It seems that this problem is caused by a malformation or malfunction of the colon and / or blind. And 'found that rabbits with En/En gene show a reduction in the rate of absorption of sodium through the walls of the blind. This indicates an excessive liquefaction of ingested material in the proximal parts of the large intestine. There may also be a late complication resulting from (and edited by) various exogenous and endogenous sources of stress, worsened metabolic status of the rabbits ipotireotico En/En but it 's very likely that the genetic difference compared to rabbits with a single gene En is precisely in the gut. The only treatment is to administer prokinetic drugs and additional hydration during episodes of stasis and follow the diet with particular attention, always providing much hay. It 'possible that the neurological symptoms (or stress) might arise from' encephalitozoonosis cuniculi cause malfunctioning bowel." - Orignal Page on Casa Freccia: Gastrointestinal Page [Google Translated page {English}]

Dana Krempels, Ph.D. at the University of Miami Department of Biology & H.A.R.E., Inc. has a great website for rabbits Houserabbit Adoption Rescue and Education Rabbit Rescue. She also answers rabbit questions on the AllExperts website. Julie aka KatnipCrzy posted a question about her rabbit Schroeder (with poop pic) and asked if he might have megacolon. Dr. Dana responded back with a great story and how she treated her rabbit with megacolon. You can read it here. [Local copy]. Here is Schroeder's Mom follow up post on

"Whilst the caecum is the usual site of impactation, megacolon, a condition where the colon is full of chronically accumulated faeces in large clumps, has been reported. The cause of this condition is not known, but it may affect white Rabbits with dark ears and spots disproportionately commonly. This megacolon syndrome, described in homozygous spotted Rabbits, results in caecal obstipation, but there is uncertainty whether this is a true dysautonomia. (Dysautonomia- Similar to grass sickness in horses. Other autonomic signs eg mydriasis, reduced tear production and salivation. Diagnosed at histopathology after Post Mortem.) - Quote comes from a post from; referencing source Notes on Rabbit Internal Medicine, Richard A. Saunders, Ron Rees Davies, Web.

There are many DVM's and people that do not belive that Mega-colon / Cow Pile Syndrome is a "medically recognized condition". If your rabbit has MC/CPS you might be in for an uphill battle depending on the VET. Here is an [HRS] House Rabbit Society article that reports on this non MC/CPS idea. Disorders of the Cecum by Marie Mead, has a small section on "COW PILE SYNDROME":

"Cow pile syndrome, named for its most visible characteristic, may result from a combination of factors, including genetic, environmental, and dietary. Though not a medically recognized condition, brief mention is included because of some of the similarities with cecal motility disorders.

Determining whether a rabbit is suffering from a condition that affects the cecum or colon requires the skill of an experienced rabbit veterinarian. The caregiver can assist in the process by providing astute and accurate observations about the problem. Additional factors aid in the diagnostic process, including the history of medications, description of the diet (including dates and details of change), any possible foreign materials ingested and date of occurrence(s), and stress factors. Regardless of the condition, appropriate diet plays a crucial role in the recovery and health of the rabbit.

Care References

"NOT true for all megacolon bunnies, but often for non mc bunnies. You will often find with many rabbits (some megacolon bunnies too) that if you cut back on the greens the sloppy poops will disappear too. ***less greens means they eat more hay and get better bigger firmer poops.*** But i agree (mine were the same) that some megacolon bunnies definitely need MORE green foods. This is really for our non mc bunnies on the list and other lists i'm on where this is a recurring question "why is my otherwise healthy bunny covered in poop?" the answer is usually too many greens." - posted by Clint Dinkums FB MC OP.

Tortoiseshell (Tort) sport image source here.

Black marked image source here.

Blue marked image source here.

Grey marked image source here.

Chocolate marked image source here.

The British Rabbit Council & the American Rabbit Breeders Association recognize the above colors. The ARBA also adds Gold & Lilac.

Gold marked image source here.

Lilac marked image source here.

This information is for reference only! See a Vet if you need help with your rabbit!
Do not try anything below before talking with your rabbit's Vet!!

What to look for in a Megacolon rabbit? "The symptoms of the disorder include big, misshapen, soft fecals, frequently covered with mucous, and a drippy bottom alternating with long, painful bouts of GI slowdown or stasis." - Kathy Smith, Rabbit Health in the 21st Century: A Guide for Bunny Parents - P. 46, Web. Buy the EBook here

Poop - Poop - Poop: You should always monitor a rabbit's poop (even when they are well), you can tell a lot from this. Look at The Rabbit Crossing 'MEGACOLON / COWPILE SYNDROME' Facebook page . It has a lot of pictures of malformed poop that a MC/CPS rabbit might have. If any of these look like your rabbit's poop, you need to take your rabbit to a rabbit savvy right now. You should already have a vet lined up before hand! If not check out the WabbitWiki vet page (and their Veterinary Emergencies webpage.) The vet link there is a great reference. Another great reference for poop pictures is the Normal and abnormal fecal and cecal feces of rabbits web page by Esther van Praag, Ph.D. Another poop page to check is kinenchen's All about poop page. And the Bunny Lovers Unite Poop Examples page. It has examples from rabbit owners.

Poop, Poop, Poop references with Pictures

About Poop - References

Rabbit poop in the garden - References

Rabbit Savvy Vets

"Opinions on medical care vary. While several caregivers I know that have nursed their megacolon rabbits through many episodes of GI slowdown some vets worry about the increased risk of the cecum rupturing during each episode. A vet who actually examined your rabbit should decide whether motility drugs are recommended or contraindicated. - and this decision may vary from episode to episode. Some vets will will prescribe a sulfa drug such as Albon or metronidazole during flare-ups. In other cases long term use of these drugs may be recommeneded. Always check with your vet before making changes to prescribed medication but don't be afraid to speak up if you feel something is not working. Most vets and caregivers do agree on the following important points for rabbits with this condition" - Quotes comes from a post from; referencing source When Your Rabbit Needs Special Care: Traditional and Alternative Healing Methods, Lucille C. Moore, Kathy Smith, Web.

  1. Encourage your rabbit to drink plenty of water.
  2. Stick to a routine While most rabbit are creatures of habit daily routine is especially important for these rabbits
  3. Once you find a diet that works don't change it unless it stops working. be consistent in what you feed and when you feed it.
  4. Encourage exercise
  5. Sanitation is crucial
  6. Minimizwe stress. While this is important for all rabbits it is especailly important for ones with a chronic condition
  7. Learn and recognize your rabbit's body language and begin treatment at the first sign that an attack is beginning. Work with your vet to identify what symtoms can be managed at home and when a vet visit is needed.

"Epsom salts have proven helpful in managing some of the unique symptoms of this disorder. Epsom salts pull fluids into the GI tract which can help soften food matter in the GI tract and also decrease the leakage of mucous and fluid that causes the wet bottom. Epsom salts should be used in conjunction with both dietary supplements and standard stasis treatments (motility drugs, subcutaneous and oral fluids, pain medications, etc.) as deemed appropriate by your veterinarian. When giving Epsorn salts, be sure to keep your rabbit adequately hydrated. A watchful, diligent caretaker and an understanding, resourceful veterinarian are the keys to managing this condition long-term while retaining quality of life. Exercise, adequate hydration, and proper diet (as defined by you and your veterinarian based on your rabbit's individual needs) are especially critical for a rabbit with this condition. Equally important is a caretaker's ability to recognize the early signs of a "flare-up" and follow a well-defined treatment plan as soon as symptoms appear." - Kathy Smith, Rabbit Health in the 21st Century: A Guide for Bunny Parents - P. 46, Web. Buy the EBook here

Long-Term Implications
"Unfortunately, many rabbits who have experienced GI ailments seem to have periodic recurrences of the problem. The good news is that, as a caring rabbit parent, you will become better at recognizing the problem at an early stage and may learn things you can do at home (e.g. diet adjustments, treating hypothermia, and/or giving sub-q fluids) to stop an attack before it requires veterinary care. A proper diet is especially important for a rabbit with recurrent GI problems. Always provide unlimited timothy hay -even if you are convinced your rabbit never eats it! Some rabbits do best with a very small amount of pellets or no pellets at all; others do best with high-quality pellets alone or with a very limited amount of greens. Work closely with your veterinarian to determine the mix of pellets and greens that works best for your rabbit. Veterinarians across the country seem to be seeing more house rabbits with GI ailments. One reason for this may be that more bunny parents are aware of what to watch for and are seeking veterinary care. Another possibility is that house rabbits are more likely to be "spoiled" with treats high in carbohydrates and sugars and such treats contribute to GI problems. We all know how hard it is to resist a rabbit who is begging for his favorite treat. Next time your rabbit begs for just a little more bread, banana, or cookie, ask yourself this question, "Do I love him enough to say NO?" - Kathy Smith, Rabbit Health in the 21st Century: A Guide for Bunny Parents - P. 47, Web. Buy the EBook here

Free Feeding study on repeat stasis/gassy bunnies.
The information on "Free Feeding study on repeat stasis/gassy bunnies" was posted to the MC Facebook by the OP, Clint Dinkums, on Tuesday, June 3, 2014 at 12:12am. This information was also posted to Bunspace's Nutrition Group by Hayward_ loves Galadriel _but will always have a special place in his heart for Lady Aspen on Jul 18, 2012 6:12:12AM. This information is for reference only! See a Vet if you need help with your rabbit! Do not try anything below before talking with your rabbit's Vet!!

This is a crossposting with permission from etherbun from a vet who has studied repeat stasis and feeding methods. Be aware disease - like dental disease is also a big factor, so this is for information only and to be used wisely (rami incidentally has a megacolon bunny too). It's for discussion. I am not advocating it for all bunnies by any means, but there is a place for it i think. - clintdinkums
Rami, a vet in Europe, who is advocating the free feeding of pellets to rabbits and has given permission, to cross post his recent post re this subject on EtherBun and he has even added information to it.

From Rami:

Many years ago, I made a study about stasis in otherwise healthy rabbits and feeding pattern. 50 owners participated.

The results showed that rabbits getting food in portions, e.g. pellets fed in the morning and in the evening, with only hay in between, were often suffering from stasis than rabbits that has access to pellets 24/24.

It was speculated that rabbits getting pellets in portion are hungry and start eating too fast, not taking the time to chew properly and wet the pellets with saliva. Once in the stomach, more fluids would be needed to rehydrate the pellets. As a result, less fluids is present in the digestive tract, dehydrating the rest of the ingesta and possibly leading to stasis.

Rabbits that have free access to pellets can take at will, when feeling the need. The %ge of stasis was very low in this group.

Another rabbit owners did the same study, independently of mine, in another country, and had the same results.

  • My own rabbits have 24/24 access to:
    • fresh water
    • pellets I mix several kind of pellets, independent of quality. The different consistency, different shape will lead to different lateral mastication movement, and seems to avoid development of spurs.
    • hay - different kind, more grassy or more coarse,
    • fresh greens and fruit
    • fresh or dry tree branches
    • fresh grasses/weeds/flowers with medicinal properties collected in fields: Herbs and Flowers.

Over the last 20 years, none has suffered stasis, intestinal parasites or coccidiosis. My megacolon rabbit has so far done well on this diet too. None took on weight or became obese (see pictures of them in the branches link). Stasis occurred only in rabbits sick with diseases: dental issue, E. cuniculi and sudden heavy shedding after a heat wave.

To me, the greater the variety of food, the better as the exact dietary needs of a pet rabbit are not known. For instance, eating the dry bark of branches will not only provide fibers, but also trigger salivation and hydration of the ingesta in the digestive system.

Each rabbit is individual though. Rarely, a rabbit does not do well with fresh greens and will need a pellets/hay diet only. Once in a while, it happens also that a rabbit shows a reaction to pellets, and another brand should be given, or no pellets at all. These cases remain exceptional.

When stasis is chronic, happening every 4 to 6 weeks, the presence of intestinal worms should be suspected. It happens that a fecal test returns negative. Yet treatment in spite of negative test result, in spite of the belief that worms are naturally present in the digestive system of rabbits, often solves the chronic stasis problem. See: Parasitic diseases.

Patricia's Treats for MC bunnies.
Patricia's Treats for mc bunnies is taken from the Facebook MC Page.

  • Cookies are roughly a 50% mix of water and solid or until fairly thick
  • Preheat oven to 375
  • Lightly coat a glass pan with olive oil
  • Spoon mixture onto pan - In dime to nickel sized portions {I use a half teaspoon}
  • Bake for around 40 minutes or until it is to your bunnys desired consistency.
Can be made with Critical Care by Oxbow or Recovery by Supreme Pet Foods to add fibre to the diet.

There are three 'flavors' of Critical Care. One is Apple Banana and the other is Anise (Anise flavor has similarities with some other spices, such as star anise, fennel, and liquorice). There is a third without flavoring called "Fine Grind". Patricia posted that you can "mix the plain one with dried cilantro".
50% mix of water and solid (Critical Care or Recovery). Mix until fairly thick.
Preheat oven to 375 degrees Fahrenheit [190 degrees Celsius]
Lightly coat a glass pan with olive oil
Spoon mixture onto pan - In dime to nickel sized portions {I use a half teaspoon}
Bake for around 40 minutes or until it is to your bunnys desired consistency.
  • Note: Patricia's Treats are based on a post (on FB) by Gretta that talks about rabbit critical care cookies. Patricia experimented with this until she got to the recipe above.
  • Another option, posted by Anna: "My secret recipe (not so secret!) is to mix Critical Care into a paste with porridge oats. I use this for Peter who loses weight without it. I've found most buns will simply eat a bowl of CC mush though (if you can't add the oats)."
  • Patricia posted on FB: "Barb Sunderland Douyard of Wonderland Rabbit Rescue makes critical care cookies. They are $5 per dozen large cookies. $3 shipping for up to 5 dozen if anyone is interested. My mc bun loves them."

"Home First Aid Kit for Megacolon Bunnies"

Source image here.

Cisapride [Propulsid]: "Propulsid stimulates the release of the hormone acetylcholine at key nerve endings along the *lower* GI tract. It restores rhythmic contractions in the intestines, so food moves out of the stomach at a faster rate. It is more specific and targeted in its effects than metoclopramide. Drug availability is restricted." - temp

Metoclopramide [Emeprid/Reglan/Maxolon]: "Do not use if obstruction - may cause rupture! Metoclopramide stimulates movement of the *upper* GI tract through a direct effect on dopamine receptors in the brain. It reduces nausea, slows/soothes the stomach and intestine, and improves the absorption of other oral medications" - more info

Domperidone [Motilium]: "is a medicine that increases the movements or contractions of the stomach and bowel. Domperidone is also used to treat nausea and vomiting..." -ref

Good article on drugs to deal with pain in rabbits: Moving Beyond Metacam. What's New in House Rabbit Pain Management

Bunny Bunch Boutique 'GI Stasis Kit'

Bunnies 1st basic 'First Aid Kits'

Napoleon Bunnyparte's basic 'Rabbit Emergency Kit'

Source image here.

This information is for reference only! See a Vet if you need help with your rabbit!
Do not try anything below before talking with your rabbit's Vet!!

Clint Dinkums; OP for Megacolon Bunnies on Facebook posted on Facebook, V2 (Updated: January 25th, 2015) information on a FirstAid Kit for MC. "My own home first aid kit for mega colon bunnies"
The info that is located in the [brackets] is added by me.

        Metacam® [meloxicam by Boehringer Ingelheim Vetmedica, Inc. {nonsteroidal anti-inflammatory drug (NSAID) with analgesic and fever reducer effects}] is an NSAID pain relief medication. It's sweet honey taste makes it very palatable, an mc bunny needs to be kept out of pain to keep his gut moving optimally, but not given sedating opiods like bupro [buprenorphine (Buprenex by Reckitt Benckiser Pharmaceuticals Inc.) opioid partial agonist-antagonists] or vetergestic [Vetergesic Multidose contains buprenorphine by Champion Alstoe; PDF info file] which will slow his gut down.

        Sub cut [subcutaneous: situated or applied under the skin] fluids like Ringers [Lactated Ringers solution] or hartmans [Aqupharm No11 - Hartmann's Solution (lactated Ringers); PDF info file - by Animalcare] can help an mc bunny enormously during difficult times, if we rehydrate the bunny first sub cut, we can then more confidently use stool softening agents like miralax [MiraLAX by Bayer AG] or lactulose [lactulose] to help rehydrate the gut and move its contents through more easily as these meds draw fluid from the whole body into the gut. i prefer miralax for bunnies but they both work well. if you cant do sub cut injections yourself then slowly and carefully giving oral fluids (plain water ideally slightly warm, rather than cool) can help a lot until you can get them to the vet for sub cuts. ask your vet to show you how to do sub cuts at home in the longer term. it can be a real life saver.

        Probiotics/prebiotics like Avipro Plus [by Vetark Pro {combination of bacteria, enzymes, electrolytes and vitamins}] or Bene-Bac [by PetAg {Help for animals under adverse conditions such as: birth, post surgery, antibiotic therapy, weaning, worming, traveling}] can help a slow gut by preventing an overgrowth of the normally low levels of 'bad' gut bacteria in bunnies.

        Cisapride [Propulsid® by Janssen Pharmaceuticals. "It acts mainly on the lower esophageal sphincter, increases the pressure in the lower part of the esophagus." - E. van Praag, 2014, MediRabbit Cisapride page] is a powerful gut motility drug that works well on the lower gut *if given in big enough doses*, frequently found to be underdosing lately.

        Metoclopramide (Emeprid=veterinary use) (or Reglan®) [Reglan®{US}-Maxolon®{UK&AU} by Union chimique belge (UCB)] is an oral or injectable gut motility drug ["The drug may induce central nervous system (CNS) effects (e.g. seizure, hyperactivity, depression, disorientation), effects that can be increased in case of concurrent intake of narcotic or sedative drugs, or tetracycline antibiotics. In case of renal failure, history of epilepsy, or gastric obstruction, the drug should not be used." - E. van Praag, 2014, MediRabbit Metoclopramide page] I have found the injectable to be much more efficient than the oral versions (emeprid/reglan), so you may need to increase your oral dose to compensate. oral should be every 8 hours. neurological side effects are sometimes noted with long term use of metachlopromide.

        Domperidone (oral) [Motilium® by Janssen Pharmaceuticals] is now the drug of choice for some UK vets in preference to Metoclopramide. until sept 2014 it was available over the counter in the uk but is now restricted to prescription only use, but hard to find in the US, it is another motility drug and nausea treatment. i used this daily on my mc bunny and it helped him a lot and we saw no side effects. helps to stimulate gut emptying and increase appetite in anorexic rabbits.

        Ranitidine, aka zantac [Zantac] is a gentle motility drug but also a gut protectant useful in bunnies who go through periods of anorexia from megacolon. for me, ranitidine is not ideal for use as a sole motility drug. it's antacid effects on the gut may even slow digestion down. the key to it is using it at the right point in the problem (ie the anorexic point) when the rabbit wont eat.

        Critical care [by Oxbow] or Recovery (in uk & usa now) [by Supreme Pet Foods] are good sources of fibre that can be made watery and warm to feed to an inappetant mc bunny. i add a small amount of extra virgin olive oil to mine which seems to help if there is impacted food in the gut.

        I keep alfalfa hay here and feed my mc bunnies the soft petals, he cant seem to digest hay now (managed until he was about 4 years old) but he is still keen to eat it so the petals are a good compromise. it's rich in protein and calcium and mc bunnies are thought to not uptake the same levels of nourishment from their food as normal bunnies so their dietary needs are slightly different. also it's a guaranteed thing to make my bunny eat when nothing else will, a great tempter back into normal eating.

        Ribwort [Plantago lanceolata; aka English plantain, narrowleaf plantain, ribwort plantain, ribleaf, buckhorn plantain, buckhorn, and lamb's tongue] also known as dried plantain (NOT the banana type thing) [Musa × paradisiaca] but a wild plant commonly found in the usa and uk is good for motilty. low in protein, high in fibre it's nice to taste and an excellent food supplement. Dried plantain example.

        [Added: Thu, Oct 9th, 2014] - "Dried plantain is a fantastic motility feed for megacolon bunnies (and non mc bunnies). It's extremely high fibre and low protein, and if you serve it dried you remove the poopy bum problem. Also you dont need to feed much for the bunnies to feel they're really having a treat. Also its found in most backyards or wild fields. You can buy it dried from the hay experts in the United Kingdom and in the USA here. Plantain info." - post by Clint Dinkums from FB

        Oxbow guinea pig vitamin c tablets. [Daily C 50mg - 90 pcs tabs] i feed one a day to my megacolon bunny and see some improvement in his particular fecal shape and output.

NOTE: "**Effective September 1, 2014, Daily C will be discontinued. Please note that this product will be available until September 1, 2014, or until all remaining inventory has been liquidated. For customers interested in a replacement for Daily C, we recommend Natural Science Vitamin C - a hay-based, high-fiber supplement containing the essential stabilized vitamin C that guinea pigs need and other animals benefit from during times of stress, illness or recovery.**" - Oxbow
  • Daily C
    • 50mg of Vitamin C per/tab is $9.27USD for a bottle of 90 tabs, about $0.10USD per/tab.
    • "ingredients: Pineapple Powder, Vitamin C (Calcium Ascorbate), Apple Fiber Powder, Cranberry Fruit Powder."
  • Natural Science Vitamin C
    • Only has 25mg of Vitamin C per/tab. It's $14.95USD for a bottle of 60 tabs, about $0.25USD per/tab.
    • "ingredients: Timothy grass, barley flour, oat groat flour, cane molasses, l-ascorbyl-2-monophosphate (vitamin C), flax seed meal, brewers dried yeast, xanthan gum, fat product, mixed tocopherols, rosemary extract"
  • If your rabbit is counting on 50mg of Vitamin C per/tab you will have to adjust accordingly. Info pulled: Fri Jul 25 21:58:25 PDT 2014

       Green Coconut Water. this is my favourite ORAL fluid for bunnies in stasis. extremely hydrating it seems to boost them more quickly than water alone. this is NOT COCONUT MILK. look for this in health food shops and even supermarkets like tesco [Tesco] stock it now. Example: Green coconut water

        Vettark critical care white powder [Vetark Critical Care Formula (CCF) by VETARK] (NOT the liquid feed by oxbow [Oxbow Critical care]). this is for hydration and fluid feeding (it's not a food but to keep electrolytes up) of completely anorexic or bloating bunnies.

       Mānuka honey [Mānuka honey from the flower of the Leptospermum scoparium]. mānuka is good for helping dry guts by drawing water into the gut from the rest of the body, so again should be used with supplemental fluids like sub cuts. does not appear to upset digestive bacterial balance in small amounts.

Once again this information is for reference only! See a Vet if you need help with your rabbit! Do not try anything above before talking with your rabbit's Vet!!

  • Note on using Oxbow Critical Care Fine Grind: Dr. Anne Martin (HRS) suggested not using Fine Grind (unless the rabbit must be fed with a nasogastric tube) referencing an article from the 2014 Veterinary Clinics of North America Exotic Animal Practice. "They state that due to the small particle size of Critical Care Fine Grind, it's more likely to go directly to the cecum in a rabbit, rather than be filtered as large fiber that moves through the colon and promotes motility. Since megacolon rabbits have a difficult time filtering fiber size, and end up with too much in their cecum anyway, I would use the regular grind Critical Care with a larger syringe."
  • "Prescription diets for rabbits." - Vet Clin North Am Exot Anim Pract. 2014 Sep;17(3):485-502. doi: 10.1016/j.cvex.2014.05.009. Epub 2014 Jul 11. [Abstract; Article]

Information on the English Rabbit (sometimes called English Butterfly) Breed

Image source: here.

Image source: here.

"From Left to Right: 2 Blue Marked, 1 Blue Sport, 2 Blue Charlies"
Image & Text from onthebrightsiderabbitry

Image source from here.

Image source from here.

"2 Marked, 3 Sport, 1 Charlie"
Image source from here.

"The Spotted Beauty of the rabbit world"
- The English Rabbit Breed. In the USA it's refered to a English Spot (sometimes the English Butterfly.)
- National English Rabbit Club: "~ The 24 Carat Club ~"

"The English Spot is a very old breed whose exact origins are not known. Bred extensively in England since 1880, the English Spot is believed to have originated from old Flemish breeds and some species of white or spotted wild rabbit. The butterfly spot on its nose prompted the French name "Lapin Papillon Angalias," or the English butterfly rabbit. Available in black, blue, chocolate, gold, gray, lilac and tortoise varieties, the English Spot buck weighs 6 pounds, while the doe weighs 7." -, Web.

"The English Spot originated in Britain in the mid 19th century and unusually for that time was intended as a fancy rather than a commercial breed from the outset. The English Spot was developed through selective breeding of non-pedigree stock bearing a resemblance to the Great Lorrainese (from which the Giant Papillon/Checkered Giant is derived). The English Spot became a very popular breed and much sought after as a household pet. It was exported to Europe around 1890, where it is known as the Papillon or English Butterfly, and to the United States around 1910." -, Web.

"It is challenging to breed a well marked English Spot because not all babies in a litter will be marked, not to mention showable, or marked well. When a pair of marked English Spots are bred together the litter will consist of 1/2 marked, 1/4 Solid (solid colored with no white), and 1/4 Charlie (mostly white with colored ears, partial butterfly, and some other partial markings). Although they can not be shown, the Solids and Charlies can be used in breeding programs. If a Solid is bred to a Charlie, the entire litter will be marked; and when a Self or a Charlie is bred to a marked English Spot, 1/2 the litter will be marked." Watch Me Run Spots, Web.

"With a normal litter "25% will be a solid color, 25% will have partial markings, and 50% will have all the required markings. The partially marked babies "typically have a mustache similar to Charlie Chaplin" and therefore are called 'charlies'" - thelife-animal, Web.

When breeders breed for an English (Spot) show rabbit these are guide-lines for judging in the UK: (The BRC)

Image source here.

Image source here.

Image source here.
Captured by
D8/ARBA Article here.
Head Markings
- Perfect Butterfly Smut
- Circle around eyes
- Cheek spots to be clear from eye circles (either cheek spot missing, deemed to be a serious fault)
- Ears neat and clear from white and not over 10.16cm (4in) long (Ears over 4in long deemed to be undesirable)
Body Markings
- Unbroken Saddle, to be herring-boned and clear in any distinct colour, from base of ears to tip of tail. (A definite break deemed to be a serious fault)
- Body or Loin Markings to be nicely broken up (as shown in the illustration) and not to catch the saddle
- Chain markings, to be as even as possible on each side
- Leg Markings, one distinct spot on each leg, front legs (5 pts) back legs (2 pts)
- Belly or Teat Spots (there should be six)
- Black, Blue, Tortoishell Chocolate or Grey -no other colour eligible or admissible (all colours to be solid and bright)
Size and Type
- 2.721-3.628kg (6lb-8lb). as illustrated (prominent dewlaps and chopped rumps undesirable)
- exhibits should be fit and alert with short tight coats and firm flesh

English Spot Pages:


- Normally most 'showable' rabbits, that are of the spotting breeds, have a thick ring of color around their nose and mouth area called a moustache (smut or butterfly.) On rabbits that inherit the En/En genes this area may be a much smaller and even have broken patches. This is what gives the Charlie Chaplin-esque moustache look. The white color on rabbits 'covers' all other colors up. If any color 'breaks through' the white, the rabbit is refered to as 'broken.'

The term charlie can have many meanings, depending on what group of rabbit owners/people you are talking to:

Image source here

Charlie Chaplin

Image source here

Charlie with only colored eye rings, ears, broken moustache (smut or butterfly). No spots.

image source

Charlie with only one spot and a light stripe.

image source.

'Show' rabbit, Rhinelander breed (En/en)

image source.

'Show' rabbit, English breed (En/en)

English Spotting gene ['En'/'en']- Side by side look: Charlies, Sports/Self & Marked/Broken
There is no defined or set definitions when refering to Charlies, Sports/Self & Marked/Broken. This grey box covers how some refer to the English breed markings. Below this box is how the majority of webpages refer to them (this seems to be a looser definition for the differences but seems to be more commonly used.) This is how this webpage refers to them. Thanks to TanRabbits for pointing this out & information.

  • On this page I refer to Partial Markings English rabbits as Charlies, from 1 spot upto (but not including) a rabbit with "show" markings. This can be a wide range. The focus here is on rabbits that have the "En/En" genes (possible MC rabbits).
  • Selfs/Sports have the "en/en" genes & are solid colors.
  • Required Markings are 'showable' rabbits. They have the "En/en" genes.

Alternative Definitions:

Lop charlie image from here

'Charlies are considered to be rabbits that have no spots and a charlie chaplin-esque moustache.' - The little lop above has only dark:
  • Eyes rings
  • Ears
  • Broken Moustache, Smut or Butterfly

image source

A Solid is called the same, a Sports or Self
  • One Color

image source.
Anything with spots is a 'Marked'

  • Can be very lightly marked (only a spot or two)
  • Upto very heavily marked
  • It can be hard to to get the right amount of spots but also the location and size of each spot

In the real world the percentages of Charlies, Sports/Self & Marked/Broken will be varied from litter to litter. The 25%/25%/50% is an average.

"The En and en genes are the English Spotting genes. They produce spots or broken patterns. A rabbit with one En gene and on en gene will have normal spotting. A rabbit with two En genes will have spotting only in the head, or be a "Charlie." A rabbit with 2 en genes will have solid color an no spotting or markings, or be a "Sport." This gene works with the plus/minus modifiers to produce more or less spotting or marking. It can also work with the Du and V genes. Examples are the English Spot and Broken Rex." - Jennys Jumpers, Web

"The plus/minus modifier genes work with the En, Du, and V genes. They are just what they sound like. The more plus modifiers that rabbit has, the more spots or pattern you will have. And the same with the minus modifiers. The more minus modifiers your rabbit has, the less spots or pattern they will have. The plus/minus modifiers are the ones you are juggling when trying to get a good amount of spots on an English Spot, for example, or the right dutch markings."- Jennys Jumpers, Web

"An example of Dominant inheritance - English Spotting Gene "En". The broken gene only needs to be inherited from one parent for the gene to express itself. Two self rabbits bred together can never produce a broken. (But do remember that a ruby eyed white may be hiding the broken gene!)" - Nock Rabbits, Web (with table below)
  • Broken x Self = 50% broken; 50% self
  • Broken x Broken = 50% broken, 25% self; 25% charlie
  • Broken x Charlie = 50% broken, 50% Charlie
  • Charlie x Self = 100% broken

Gene's Function (Info from: Amy's Rabbit Ranch)
En - "English Spotting: Causes white spots within the solid color, also called Broken. Works with the plus/minus modifiers to intensify or decrease the amount of white.
- Example: "English Spot, Tri-color, any Broken En/En = "Charlie", too much white"
en - "Self-Colored: Normal color, no white spots"
- Example: "Any selfs. En/en = normal broken, en/en=self."

Rabbit Genetics

Side by side comparison of Charlie/Chaplin, Sport/Self & Marked/Broken English (Spots) & Checkered Giants
Partial Markings
Charlie (25%) - Chaplin
2 "En" genes
Homozygous (En/En) rabbits are almost completely white.
"Dominant homozygous rabbits, En/En, are mostly white and are called Charlies (grades 8-12). The occurrence of grade 12 Charlies is particularly rare."

Black charlie image source here.

Black charlie image source here.
Solid Color
Self (25%) - Sport
2 "en" genes
Homozygous (en/en)for the recessive wild-type allele are self-colored.
"Recessive homozygotes, en/en, have no white spotting on the body (grade 0)"

Blue sport image source here.

Tortoiseshell (Tort) sport image source here.

Black sport image source here.
Required Markings
Broken (50%) - Marked
1 "En" & 1 "en" gene
Heterozygous (En/en) rabbits "normally spotted."
Heterozygote with the 'ideal' phenotype (grades 5-7)

Black marked image source here.

Blue marked image source here.

Chocolate marked image source here.

Checkered Giant chart below: "Figure 3. Rabbits with En/En , En/en and en/en genotypes at the English spotting locus. The genotypes are identified by the three coat color phenotypes, respectively. doi:10.1371/journal.pone.0093750.g003"

Coat color genetics of rabbits [Spot grading chart] - Rabbit Production By Steven D. Lukefahr, Peter Robert Cheeke, Nephi M. Patton, 2013, Page 211, Web. [Source image Colour Inheritance in Small Livestock, Roy Robinson, 1978]

"Grade 0" referes to a true Solid Color rabbit (Selfs - Sports)
"Recessive homozygotes, en/en, have no white spoting on the body"

Other spotting terms: Real & Fake Charlies, Booted, Blanketed, and Dalmatian

Once again most all of these terms come from breeders that need a way to describe the color patterns on rabbits. Not all use the same terms and numbers to describe the rabbit's fur coloring & patterns. Most of this information comes from different breeder's webpages, this may upset some people.

Broken Marking Patterns Table #1

image source here

A Charlie is a broken rabbit with very little color marking patterns. They may look like grades 8-12 and could be a En/En (could have MC) rabbit.
  • "Charlies" normaly will have less than 10% color and sometimes are refered to as 'True Charlies'. They can carry the En/En genes (could have MC).
  • The occurrence of grade 12 Charlie is particularly rare.

False Charlies: They look exactly like 'True (En/En) Charlies' but they carry the En/en genes and will not have MC.

image source

Elmer - thanks ForgetfulDoryFish
Broken - 'flase charlie' rabbit. This happens when one parent is a self/sport/solid (en/en) and the other is a 'required markings' broken (En/en).

image source

Brokens are in-between charlies and booted. They are En/en rabbits with 'normal spotting', they may look like grades 4-7.
  • Most brokens will have En/en genes (no MC)
  • "Brokens should have at least 10% color, but no more than 70% color." - reference
  • "Broken ... is a rabbit ... with at least 10% color ... but less than 50%." - reference
  • "Occasionally, rabbits with only one broken gene will have less than 10% color and be referred to as Charlies, even though they are not genetically Charlies." - reference

Patched: A white rabbit with patches of color.

image source
Broken - 'patched' rabbit

image source

Booted is a broken with more color than white. They may look like grades 1-3. "Booted and false charlies are both En/en but have modifiers changing the amount of white in the pattern (less or more)" - reference
  • "Booteds are brokens with more than 70% color." - reference
  • "Rabbits which have more than 50% color are often referred to as being booted." - reference

Blanketed: With brokens the colored portions can "occur in a patched or a blanketed pattern with white fur in between" - [ref] "The Blanket pattern will have more color on body and head." [ref]

"As long as the pattern is even, no preference should be given for blanket or spotted pattern - except in the breeds that disqualify over 50% color." - [ref]

image source
Broken - 'blanket pattern' rabbit

Researching: Smoke Pearl, Tortoiseshell, Orange, Fawn, Cinnamon, Dalmation, Harlequin, Himalayan and Satin are also recognised in the UK. - See more at: Dalmatian Rex - As obvious in the name, this rabbit breed has beautiful black spots over a snow-white body, looking rather like a child’s stuffed toy. At the show they are really made to wow! With correct handling Dalmatian Rex’s can become your best friend and a pleasure to spend time with! Dalmation rabbits are to have no color on the spine and separated spots

Information on the Checkered Giant (called Giant Papillon in the UK) Breed

Image source: here.

"Mix Checkered Giant Kits - Marked & Sports

"The Rabbit Beautiful"
- In the USA it's refered to as a Checkered Giant
- Called the Giant Papillon in the UK. [Papillon = Butterfly in French]

The Checkered Giant (Giant Papillon) carries the same spotting genes as the English breed of rabbit (En & en).
  • "The English Spot was developed through selective breeding of non-pedigree stock bearing a resemblance to the Great Lorrainese (from which the Giant Papillon/Checkered Giant is derived"
  • The latest research paper & study on Megacolon was done using Checkered Giants. This paper was published on April 15, 2014. "This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited." Current & free access!! It does not talk about care, but it is a serious study that anyone can read.

"The Checkered Giant Rabbit was developed in Germany in 1904 by crossing a Reinish Checker Rabbit or a Checkered Lop with a black Flemish Giant Rabbit. They were introduced to the United States in 1910 and have been predominantly bred for show and the pet trade rather than for meat. The American strain has markings slightly different from the European strain." -, Web.

"The Checkered Giant originated in the Lorraine region of France towards the end of the nineteenth century and is known there as the Great Lorrainese. Bred from Flemish Giants, large French lop-eared rabbits and spotted rabbits, they were initially multi-coloured or natural wild coloured but further development produced the characteristic 'butterfly' markings that have made the breed popular since the 1920s. Exported to the United States at the beginning of the twentieth century, they are known there as the Checkered Giant, and in Britain as the Giant Papillon. They are considered the same breed, although the Checkered Giant has been selectively bred to a type distinctly different from the Giant Papillon." -, Web.

"The Checkered Giant was originally bred near the end of the 1800's in Lothringen Germany when Flemish Giants,French Lops, and spotted rabbits were bred together to create the Land Kaninchen. The Land Kaninchen weighed 10 to 12 lbs and did not have the butterfly marking on the nose. Breeders continued to breed them with Flemish Giants throughout Germany to increase their size, producing the Lorraine rabbit which was also called the Great German Spotted rabbit. Though these rabbits still did not have the distinct butterfly pattern on the nose, they did resemble the English Spot and came in a wide range of colors. In 1904, Mr. Otto Reinhardt of Reinfalz Germany, bred the Great German Spotted rabbit to a black Flemish Giant producing the Checkered Giant that we know today. The first Checkered Giants arrived in America in 1910. During the early years, this rabbit was known by a number of names such as the German Spotted, the Spotted Giants, American Spotted, Giant Checkers, and the American Checkered Giants. Though over the years, the Checkered Giant was recognized in a large variety of color combinations, they gradually reduced the acceptable colors to Black on White and Blue on White. The first ARBA standard was written in the early 1900's shortly after the first imports from overseas." Mosaic Rabbitry, Web.

"The Checkered Giant is one of the largest breeds with a minimum weight of 5kg (11lbs) and many weighing over 6kg (13lbs). The Checkered Giant has a slender, muscular build. The hare-like body has a long, arched back, long, powerful legs and a wide head with large, broad ears held firmly upright. Checkered giants have a white coat with coloured markings. They have coloured ears, rings around the eyes, cheek flashes and a butterfly-shaped marking on the nose. A dorsal stripe (herringbone) runs down the spine from ears to tail, with coloured patches on the haunches. Breeding well-marked Checkered Giants is not straightforward. In most litters around half the young will have good markings, there are usually self-coloured (one plain colour) and partially marked young as well. Rabbits with partial markings are often called 'Charlies', this is thought to stem from the partial butterfly marking on the nose which looks like a 'Charlie Chaplin' moustache. Checkered Giants have smooth, short hair." -, Web.

Other reference for research on MC/CPS in rabbits.

PLEASE NOTE!! The "Research Paper" section below has information and links to REAL RESEARCH PAPERS. Rabbits were breed and put down to study Megacolon and the effect the En gene has on rabbits. They may include necropsy (autopsy) pictures. The language and images may upset some!

  • Groups:
  • Books:
  • Medical:
  • Posts:
  • Megacolon Research:
    • - 2014; "The KIT Gene Is Associated with the English Spotting Coat Color Locus and Congenital Megacolon in Checkered Giant Rabbits (Oryctolagus cuniculus)"
      Luca Fontanesi, Manuela Vargiolu, Emilio Scotti, Rocco Latorre, Maria Simonetta Faussone Pellegrini, Maurizio Mazzoni, Martina Asti, Roberto Chiocchetti, Giovanni Romeo, Paolo Clavenzani, Roberto De Giorgi, Published: April 15, 2014, PLoS ONE 9(4): e93750. DOI: 10.1371/journal.pone.0093750. [Abstract]; Research paper (local copy pdf-3.1MB)
    • - 2014(?); Gut flora comparison for rabbit nutrition book
      After the 2014 HRS Educational Conference (Taking Rabbit Knowledge to a Higher Level, September 27-28 hosted by the St. Louis House Rabbit Society), Christie Taylor (HRS Nationally Licensed Educator) posted about how Susan Smith, Ph.D. (helps run the Wisconsin HRS chapter), "is collecting samples from US megacolon rabbits for analysis. She's hoping to compare their gut flora to the microbes normally present in non-MC rabbits and to aid clinicians in creating therapies for MC bunns based on those results." This may be for the book on rabbit nutrition she is working on currently.
    • - 1995; "A striking malformation in a spotted rabbit"
      by Wieberneit D (1995), Published November 1st, 1993 by DTW. Deutsche tierärztliche Wochenschrift [Info]
    • - 1995; "Pathophysiological and functional aspects of the megacolon-syndrome of homozygous spotted rabbits."
      by Böderek D, Türk O, Lovén E, Wieberneit D, Wegner W. (1995) from Institute of Animal Breeding and Genetics, Hannover School of Veterinary Science, Germany., Zentralbl Veterinarmed A. 1995 Nov;42(9):549-59. doi: 10.1111/j.1439-0442.1995.tb00410.x [Abstract]; Research paper (local copy: PDF 4.7MB)
    • - 1995; "Albino Rabbits Can Suffer From Megacolon-Syndrome When They Are Homozygous For The 'English Spot' Gene (En/En)"
      by Wieberneit D. and Wegner W. (1995) of the Institute of Animal Breeding and Genetics, Hannover School of Veterinary Science, Germany. Published in the World Rabbit Science 1995, 3(1), p. 19-26. doi: 10.4995/wrs.1995.236 Research paper (local copy: PDF 3.1MB)
    • - The problems of spotted breeds of rabbits:
      • - 1991; "1. Fattening and body condition at slaughter, organ parameters"
        by Wieberneit D, Mahdi N, Zacharias K, Wegner W. (1991) Dtsch Tierarztl Wochenschr. 1991 Sep;98(9):352-4. [Abstract]
      • - 1992; "2. Further results on the variation of characteristics in fattening and breeding animals"
        by Mahdi N, Wieberneit D, Wegner W. (1991) Dtsch Tierarztl Wochenschr. 1992 Mar;99(3):111-3. [Abstract]
      • - 1993; "3. Variability of the pigmentation grade, ganglionic intestinal wall supply, relationship to pathogenesis--animal breeding and animal welfare aspects"
        by Gerlitz S, Wessel G, Wieberneit D, Wegner W. (1993) Dtsch Tierarztl Wochenschr. 1993 Jun;100(6):237-9. [Abstract]
      • - 1994; "4. Morpho- and histometric findings in the CNS and thyroid glands and the hormone content in blood at slaughter of hybrid rabbits, and estimation of the heterosis effect"
        by Flemming K, Kühnel C, Wieberneit D, Wegner W. (1994) Dtsch Tierarztl Wochenschr. 1994 Nov;101(11):434-9. [Abstract]
  • Ancillary Research
  • - 1919; "Studies in heredity in rabbits, rats, and mice"
    Castle WE., (1919) Carnegie institution of Washington. Publication no. 288, doi: 10.5962/bhl.title.33682 - [Paper]
  • - 1924; "Linkage of Dutch, English, and Angora in Rabbits"
    Castle WE., (1924) Proceedings of the National Academy of Sciences USA, 1924 Mar;10(3):107-8., Bussey Institution, Harvard University, Boston, PMCID: PMC1085547. [Abstract; Paper]
  • - 1928; "Further notes on Dutch and English rabbits"
    R. C. Punnett F.R.S., (1928) Journal of Genetics, November 1928, Volume 20, Issue 2, pp 247-260. [Abstract -N/A; Paper]
  • Metacam® [meloxicam by Boehringer Ingelheim Vetmedica, Inc.]
    • 2014; "Molecular analysis of the microbiota in hard feces from healthy rabbits (Oryctolagus cuniculus) medicated with long term oral meloxicam."
      Eshar D, Weese JS. (2014) BMC Vet Res. 2014 Mar 11;10:62. doi: 10.1186/1746-6148-10-62. PMID:24618207 [Article]
    • 2014; "Pharmacokinetics of meloxicam administered orally to rabbits (Oryctolagus cuniculus) for 29 days."
      Delk KW, Carpenter JW, KuKanich B, Nietfeld JC, Kohles M. (2013) Am J Vet Res. 2014 Feb;75(2):195-9. doi: 10.2460/ajvr.75.2.195.PMID: 24471756 [Abstract;]
    • 2013; "Effects of multimodal analgesia with LowDose buprenorphine and meloxicam on fecal glucocorticoid metabolites after surgery in New Zealand white rabbits (Oryctolagus cuniculus)."
      Goldschlager GB, Gillespie VL, Palme R, Baxter MG. (2013) J Am Assoc Lab Anim Sci. 2013 Sep;52(5):571-6. PMID: 24041213 [Abstract;]
    • 2013; "Pharmacokinetics of meloxicam in rabbits after oral administration of single and multiple doses."
      Fredholm DV, Carpenter JW, KuKanich B, Kohles M. (2013) Am J Vet Res. 2013 Apr;74(4):636-41. doi: 10.2460/ajvr.74.4.636. PMID: 23531074 [Abstract;]
    • 2009; "Single and multiple-dose pharmacokinetics of meloxicam after oral administration to the rabbit (Oryctolagus cuniculus)."
      Carpenter JW, Pollock CG, Koch DE, Hunter RP. (2009) J Zoo Wildl Med. 2009 Dec;40(4):601-6. PMID: 20063804 [Abstract;]
    • 2009; "Behavioural effects of ovariohysterectomy and oral administration of meloxicam in laboratory housed rabbits."
      Leach MC, Allweiler S, Richardson C, Roughan JV, Narbe R, Flecknell PA. (2009) Res Vet Sci. 2009 Oct;87(2):336-47. doi: 10.1016/j.rvsc.2009.02.001. PMCID: 19303122 [Abstract
    • 2009; "Comparison of Side Effects between Buprenorphine and Meloxicam Used Postoperatively in Dutch Belted Rabbits (Oryctolagus cuniculus)"
      Coreen S Cooper, Kelly A Metcalf-Pate, Christopher E Barat, Judith A Cook, and Diana G Scorpio (2009) J Am Assoc Lab Anim Sci. May 2009; 48(3): 279-285. Published online May 2009. PMCID: PMC2696831 15141807 [Abstract; Article]
    • 2006; "Effect of meloxicam and butorphanol on minimum alveolar concentration of isoflurane in rabbits."
      Turner PV, Kerr CL, Healy AJ, Taylor WM., (2006) Am J Vet Res. 2006 May;67(5):770-4. PMID: 16649908 [Abstract;]
    • 2006; "Pharmacokinetics of meloxicam in rabbits after single and repeat oral dosing."
      Turner PV, Chen HC, Taylor WM., (2006) Comp Med. 2006 Feb;56(1):63-7. PMID: 16521861 [Abstract;]
    • - 2003; "The effect of meloxicam and deendothelisation on vascular responses in the rabbit renal and ear arteries."
      Fackovcova D1, Vojtko R, Kristova V, Kurtansky A. (2004) Bratisl Lek Listy. 2004;105(1):3-7. PMID: 15141807 [Abstract; Article]
    • - 2002; "The post operative analgesia (Metacam) study"
      Study completed Summer 2002, "The Exotic Animal Service at Edinburgh Vet School ran a study into the efficacy of "Metacam" as an analgesic in rabbits. The study was designed to examine objectively the analgesic effects of "Metacam" and to determine which of two doses and which route of administration (by injection or by mouth) is most effective in controlling the pain associated with spaying/castration in rabbits. 100 pet rabbit owners in Lothian were invited to have their rabbit neutered at Edinburgh Vet School's Small Animal Hospital, at a reduced price. Although mainly funded by Boehringer (the manufacturer of Metacam), the Rabbit Welfare Fund provided a top-up grant of £500 to enable about 20 rabbits from rescue centres to be enrolled in the study complete free of charge." [Information;]
  • Vitamin D
    • - 2014; "Rabbits kept indoors could be vitamin D deficient"
      Article based on study below., April 9, 2014.
    • - 2014; "Effects of ultraviolet radiation produced from artificial lights on serum 25-hydroxyvitamin D concentration in captive domestic rabbits (Oryctolagus cuniculi)"
      Jessica A. Emerson, DVM; Julia K. Whittington, DVM; Matthew C. Allender, DVM, PhD; Mark A. Mitchell, DVM, PhD, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802. (Emerson, Whittington, Mitchell); Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802. (Allender). American Journal of Veterinary Research, April 2014, Vol. 75, No. 4, Pages 380-384, doi: 10.2460/ajvr.75.4.380 [Abstract; Article]
    • - 1995; "The Truth About Vitamin D: is it the answer to rabbit dental disease?"
      Based on a paper by Frances Harcourt-Brown, [Webpage article; dated 10/2/2012]
    • - 1995; "A review of clinical conditions in pet rabbits associated with their teeth"
      FM Harcourt-Brown, Veterinary Record 1995;137:341-346 doi:10.1136/vr.137.14.341 [Abstract]
    • "very neat view of the inside of a rabbits mouth" - teeth
  • Bloat (Acute Gastrointestinal Dilation - distended stomach / gas - Gastric Dilatation-Volvulus (GDV))
  • GI Stasis
    [Overview | English Spot Breed | En/en Genes | MC/CPS Background | Care | Reference & Research | What is Megacolon?]
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