Digestive Problems in Cats - Megacolon and Constipation

Constipation and hard stools with megacolon - also flea conrol monthly products.

Question: Update on Calico: She is doing well, what with lactulose and occasional enemas with Petenema. I cannot praise the latter enough, they have save me many costly trips to the vet. I have discovered that there is usually a dry fecal plug at the opening. Once that comes out, she empties. I guess it would be pretty obvious that the stuff at the very exit would be the driest and act as a plug. However, neither of the three vets who have worked on her have passed on this very important information.

Of course, if I don't do the enema in time, i.e. before too much fecal mass collects, I will have a problem in so much mass. So the trick here is to monitor her output and to up the lactulose first before the enema.

So I have arrived at a strategy that does work, and perhaps in one of your newletters you could pass on this information about the "plug" and the use of the enema. My specialist vet who charged 800 bucks for a bad case, and 400 for a less impacted colon, wasn't too interested in my strategy and discovey. I hate to be cynical, but do you think there might have been a vested interest in her lack of interest? Kind of sad, for the animal and the pet owner.

I wonder if you have an opinion on Frontline vs Advantage for flea control?

Thanks and regards , Jill

Answer: Jill-

I am glad that you have found a strategy that works for Calico.

We have found that giving ranitidine (Xantac Rx) at 1 to 3.5mg/kg of body weight every 12 to 24 hours sometimes helps with expulsion of stools, as well.

I am not familiar with the active ingredients of Petenema (tm?) but it is important in cats to avoid the use of enema solutions containing sodium phosphate, such as Fleet (tm) enemas. It is usually OK to use soapy water enemas or to use enema solutions that contain docusate (DSS).

I think that imidocloprid (Advantage tm) and fipronil (Frontline Topspot tm) are pretty close in effectiveness at controlling fleas. In some areas of the country vets really seem to prefer one product over the other so there may be geographic variabilities in the susceptibility of fleas or else the sales people are a lot better for one product in those areas. We use Frontline Topspot predominantly in our practice, primarily because there are a lot of ticks here and Advantage does not kill ticks.

Mike Richards, DVM 12/22/2001

Megacolon treatment - cisapride (Propulsid Rx) and ranitidine (Xantac Rx)

It is still possible to get cisapride (Propulsid Rx) from compounding pharmacies and many vets feel that it is helpful for megacolon problems. An alternative medication is ranitidine (Xantac Rx), which seems to have similar effects in some cats. The usual dosage of cisapride is 1.25 to 2.5mg given 15 to 30 minutes prior to eating and the dosage of ranitidine is 1 to 2mg/kg every 12 hours.

Mike Richards, DVM 1/15/2001

Megacolon/Perineal hernia

Question: Hi there. When my kitty, Baby Boy, started having troubles, I began to search for information on the Internet and was so glad to find this site. It has been very helpful, so I decided to become a member, in hopes you may be able to help me with my problem. In June I brought him to the vet because he was swollen where his tail begins. I also felt like maybe he was a little swollen near his rear on both sides. I showed the vet this and he said, if it is the same on both sides, that is probably just the way he is. He thought that BBoy has been bitten by another cat, and put him on antibiotics. Well, after a while that went away, but came back again, about a month later. This time, he was leaking an awful smelling mucus, and again, a little swollen at his tail. He was also straining terribly to poop, with no results. Very constipated. I brought him in again, and he had an enema, full blood work up, and x-rays. The colon was not abnormally swollen. The vet suggested the possibility of taking out part of the colon, if it became necessary. He also suggested doing a Barium study first, then an endoscopy, if necessary, or possibly exploratory surgery. This scared me, so I took him to another vet. They did the Barium study there, which apparently was pretty normal. No polyps or tumors. The vet pulled out a hard fecal ball about 3 inches in diameter, which accounted for the swelling at his tail. He had one decent size poop after another enema. She said he had chronic constipation. She put him on Propulsid 10 mgs and Lactulose 1cc orally daily. We switched him to wet food only, and I was sneaking him Metamucil. Almost a week later, BBoy still was not pooping. I brought him back in, she said he is still swollen, she referred me to a surgeon. He did a third enema, and diagnosed the problem as bilateral perineal hernias. He said he could move his finger from side to side, which your not supposed to be able to do. He recommended surgery to build a wall to get the poop moving in the right direction again. He said it was getting stuck in the fallen walls. I talked with the first vet about this, and he disagreed strongly, never having seen such a thing in a cat, only dogs, whose anatomy is different. He didn't say that it was impossible, however. He was leaning toward the Mega Colon, which, were the symptoms that BBoy was having. The other vets disagreed strongly. The colon wasn't swollen. I put the vets on the phone with each other to let them duke it out, me being thoroughly confused and scared for my BBoy. Neither came to the conclusion that either surgery would completely solve the problem. They both agreed they were trying to do the best they could for my cat. I have decided to hold off for a while, just not knowing what to do. In the meantime, I have upped the Lactulose, but not the Propulsid, in case it is perineal hernias. Still no poop, but he has the appetite of a horse. The doctor says he is well hydrated, and in every other way seems normal. How long can he go without pooping? Where is it all going? How come his appetite is so strong? Both surgeries are very expensive, I can't afford really to do either anyhow. I was hoping that there was some sort of Fund to help, but after asking around, there is none. I love my kitty, and want what's best. Any suggestions?

Answer: C-

Perineal hernias are not very common in cats but it definitely occurs in them. I think that the swelling you describe is more likely to be due to a perineal hernia than to megacolon, though, just based on what we see in our practice.

There was a report in the Journal of the American Animal Hospital Association (Oct 1992, Welches, et al) on 40 cases of perineal hernias in cats. The primary signs reported were straining and constipation. Surgical repair was recommended but the authors strongly advised being cautious to rule out megacolon prior to surgery. This should be possible based on the barium X-ray studies that have already been done, although you are reporting disagreement among the vets looking at these films.

The medical treatment for the conditions is the same, with lactulose sufficient to make the stools stay soft being the mainstay of treatment. Currently it seems better to use low residue foods rather than higher fiber foods. Eukanuba Low Residue (tm) food is commonly recommended at this time. Cisapride (Propulsid Rx) is commonly used, as well. We have good success at medically treating colon problems but perineal hernias will almost certainly recur even with careful medical management, so that may help in differentiating the conditions, as well.

In the long run, if there are perineal hernias it is likely that surgery would be less expensive than medical treatment but I know that the up front cost can be prohibitive.

Mike Richards, DVM 9/13/2000

Chronic constipation/megacolon problems

Question: Dear Sir I am a subscriber as per attached.

My 10 year old Siamese is having a great deal of difficulty moving her bowels. This has been the case for almost two years. We now have her on one pill of Propulsid a day as well as 4mg of Lactalose, and she still does not go every day and when she does the stool is VERY HARD and comes out in a small ball. She strains a great deal when going and sometimes, comes out of the litter box in her position and goes on the carpet or wherever she can.

Can you advise anyway to help her other then what we are doing now. I have been told by several Vets that she should have the runs with what we are giving her. She is a sweetheart and it breaks my heart to see her strugle so.


Answer: Lynn-

There are a number of approaches to chronic constipation/megacolon problems in cats. It is sometimes necessary to try several approaches to find one that works for a specific cat. For some cats, medical treatment won't work. In these cases, there is a surgical technique to help with the problem, a sub-total colectomy.

The maximum dosage of cisapride (Propulsid Rx) is around 10mg three times a day. This medication helps many cats with constipation and megacolon, so you may wish to consider asking your vet about increasing the dosage.

Lactulose is used at approximately 1ml per 10 lbs of body weight three times a day to start, usually. However, it may take up to 3ml three times a day in some cats to produce soft moist stools. The goal is to give the amount of lactulose it takes to get soft moist stools without giving so much that the cat is uncomfortable due to excessive gas or diarrhea. I am assuming that you are referring to milliliters (ml) instead of milligrams (mg), because lactulose is 666mg/ml, so 4mg would be a really low dose.

There are two schools of thought on dietary control of constipation in cats. Some cats definitely seem to respond to increased fiber in the diet. Increasing the fiber can be accomplished by changing to a diet like Hill's w/d that already has fiber in it, or by adding Metamucil (tm) 1/4th tsp. once a day, to the diet or by adding canned pumpkin at the rate of about 2TBS per day. Other cats get worse if fiber is increased and these cats do better on low fiber diets. The one that most vets seem to like is Eukanuba Low Residue (tm) diet but any very low fiber diet will work. Your vet can help you find one if you can't get the Eukanuba diet easily. I don't know any good way to sort through this problem except to start with one of these and see what happens. Since there seems to be less problems if you use a low residue diet and it doesn't work than when a high fiber diet doesn't work, I'd probably start with the low residue one and see what happens.

We find that in a few cats it really helps to give subcutaneous fluids when constipation seems to be coming on even though we have generally good control of the constipation problem. I have not seen this recommendation in the literature that I can remember so this is just our experience, not something that has been confirmed.

Sub-total colectomy is a surgical procedure in which most of the colon is removed. This usually causes diarrhea for a month or so after surgery, and a few cats always have soft or diarrhea consistency stools, although they usually retain control over defecations, so this may still be better than the constant constipation. This is a major surgery and it should be a last resort when medical treatment won't work, but it is an option if you get to that point.

It may take some work and some give and take with your vet to get to the point that you can keep your girl comfortable, but most of the time we have been able to control this problem medically.

Good luck with this. I do think you have room to work on the dosing of cisapride and lactulose and that might help.

Mike Richards, DVM 4/4/2000

Megacolon or chronic constipation

Question: Dear Dr. Mike:

I have a 7 1/2 year-old spayed female named Munchkin, whom I have had since she was abandoned at approximately 3 weeks old. She is a social and affectionate cat. About 3 years ago, one evening I noticed she was acting weird, running around the room crouched down, stopping in a corner, running to another corner, when all of a sudden she stopped, squatted and pooped, right on the floor! I was quite surprised, but didn't yell at her, cleaned it up, and went to my cat care books, which said that inappropriate elimination was usually a behavioral problem, possibly a protest at some change in the cat's life. This could be true, I supposed, since we had several months before taken in a cranky, hostile 11-year old female who had belonged to my husband's parents, when they could no longer care for her. Friskey and Munchkin frequently "tangled", with Munchkin usually running away. Other than the pooping on the floor, though, Munch seemed normal. When this continued for a few weeks, we took her to the vet, she examined her, and we decided it was behavioral. We tried confining her to a room with a litter box, and she used the box, and we would let her out, and she would use the floor. She has never, to my knowledge, urinated outside of the box. After a few weeks, she started using the box again consistently, and we decided the problem was solved.

Not so fast. After a few months, it started again. This time I was less inclined to believe the behavioral diagnosis, since nothing had recently changed - Friskey was still there, but months had gone by with no problem. Then one night I came across fresh stool on the floor, and noticed bright red blood on the side. I immediately panicked, and took her to the vet the next day. They took a urine sample, which showed crystals in the urine, along with bacteria and red & white blood cells. This was diagnosed as a bladder infection, and she was put on antibiotics. We reasoned that it hurt her to urinate, so she was running from the box after urinating, holding the stool in until she couldn't hold it anymore, and then pooping on the floor. The vet could also feel that she had a lot of hard, dry stool in her colon, and gave her an enema. At the time she was on a steady diet of dry Feline RD, and had been for a few years. We have since switched her to Purina OM and a spoonful of canned Feline RD at night, to give her less fiber and more moisture, to try to prevent constipation, along with occasional stool softeners.

The antibiotics seemed to work, because after several incidents, she returned to using the box full-time. However, this problem has continued intermittently for 3 years now, a few months using the box, several weeks using it & not using it, then back to using it full-time, with various treatments which didn't work, always going back to the antibiotics. My vet hesitates to continue prescribing antibiotics, but repeated urine tests show bacteria in the urine, and nothing else seems to work. Our other concern is that she will develop megacolon, because x-rays have shown that her colon is larger than normal, but not dangerously so yet.

My question is, do you know of any other conditions that might be causing her problem? My vet and I are baffled. It appears to me, when I see her crouching down, scurrying around, that her stomach hurts. If I see her scratching at the carpet, and pick her up and take her to the litter box & put her in, she will immediately squat, and after a lot of straining, will produce one or two stools. She then covers it up and runs from the box like she is being chased. As I mentioned before, she has consistently used the box to urinate. We also notice that she seems to "twitch" a lot, where we can see spasms rolling along her body - no idea why this is.

I came across an article on the Morris Animal Foundation Web Site concerning Intestinal Problems in Cats, "Determining an Improved Treatment Method," which talks about "two major complaints of pet owners with cats suffering from constipation is that their cat seems to be in extreme discomfort, and that multiple visits are required to the veterinary hospital with their sick pets. Cats experiencing painful gastrointestinal disorders may exhibit severe constipation and other serious symptoms. Scientists think this defect may be a functional disorder of the smooth muscle of the colon..." "Investigators from the University of Pennsylvania's School of Veterinary Medicine are conducting a study led by the principal investigator Dr. Robert Washabau. The study, 'Efficacy of Gastrointestinal Prokinetic Agents in the Cat,' will explore several ways of relieving painful gastrointestinal disorders."

I have tried to get more information on this subject but have been unsuccessful. Not being a vet, I don't even know if this could in any way be related to Munchkin's problem, but the "extreme discomfort" part rang a bell. I found your web site while attempting to research this, and joined so I could ask you this question. I'm sorry this is so long, but I wanted to give you as much information as possible. I am much less concerned about cleaning up occasional messes on the floor than I am that my cat be healthy and happy. She brings us much joy, and we want to keep her as long as possible. Friskey passed away almost 2 years ago at the age of 13, with liver cancer, and one year ago we adopted an 8-week old male, Peabo, who has a very sweet personality, likes his older sister and keeps her company when we're not around. No more hostility, and absolutely nothing we can think of that wouldupset her & cause a behavioral "protest."

Any suggestions or ideas will be greatly appreciated. Thank you for your time.

Sincerely, Rebecca

Answer: Rebecca-

The disorder that ultimately becomes megacolon starts out as described in the passage from the Morris Animal Foundation, that you found. At the present time there are a lot of theories about why the smooth muscle disorder develops, but as the smooth muscle that composes the wall of the colon becomes weaker over time, the colon increases in size and eventually constipation becomes a problem. When this goes on long enough, the colon increases in size to accommodate the increase in stool and the result is the condition referred to as megacolon. In a few patients, this problem develops because there is obstruction of the colon in the pelvis, usually due to a pelvic fracture that has not healed with the full width of the pelvis unobstructed.

Increasing the fiber in the diet is sometimes helpful in slowing the progression of this problem. However, at some point it usually becomes necessary to use some sort of medical treatment. We have had very good luck, in our practice, using lactulose (Cephulac and Duphalac Rx), usually 1 to 3ml two or three times a day as necessary to keep the stools moist and soft. In many cases use of lactulose has been sufficient for a very long time. If it stops working we try cisapride (Propulsid Rx). However, this medication has recently been restricted by the FDA, I think, and may not be available for cats in the future. I am not aware of any major problems in cats with the medication but it isn't marketed or approved for cats and it was causing some problems in humans, apparently. I am not sure if the restrictions on human use will affect availability of the medication for cats but it seems likely. Alternative medications that might help include ranitidine (Zantac Rx) and nizatidine (Axid Rx) but we have never tried these, as far as I can remember.

It is still necessary to treat for behavioral aversion to the litterpan while treating for megacolon or chronic constipation in cats. The reason for this is that any aversion at all can contribute to the progression of the colon problems and it is easy for a cat to develop the opinion that the litterpan, the type of litter or some other factor is causing it pain when it tries to have a bowel movement. Providing more than one litterpan, changing types of cat litter or providing a choice of cat litters in different pans and making sure that the cat has "private time" with a litterpan, undisturbed by housemates, can all be helpful.

We sometimes seem to see a correlation between repeated bouts of cystitis and colon problems. I am not sure this isn't just a problem with distinguishing which one is the problem, though. However, we have used amitriptyline to treat some of the cats in our practice who have difficult to treat or recurrent bouts of cystitis and it has been helpful. It seems to reduce bladder pain. Since it may not be clear at this time which is the actual problem, I don't think a short course of amitriptyline to see if it is helpful would be a problem, if your vet thinks it might help, too. As long as it seems justified I don't worry too much about using antibiotics over and over again for cystitis. There doesn't seem to be a major problem with resistance as long as they are used for at least three to five days each time they are used.

Lastly, surgery can be done to alleviate the symptoms of constipation. Personally, I would put this off until all medical treatment options are exhausted but some vets think it should be done earlier than I do. If there is a problem with the pelvic diameter due to a previous injury it may help to consider surgery to widen the pelvic inlet. We have sent a couple of patients to orthopedic specialists for this when it seemed like it might help and have had pretty good luck in those cases, so far.

Hope this helps some.

Mike Richards, DVM 3/30/2000


Q: I have a 12 year old cat that has been battling with megacolon. It has become more severe in the past year or two. Right now I treat him with 2 1/2 ccs of Laxatone dailly and subQ fluids (150 ccs) 1-2 time per week. This seemed to work for awhile. Lately, he has been getting quite constipated. I have tried Propulsid to no avail. I feel if I could only find some kind of food, drug, anything that would soften his stool, he could expel the stool. The problem seems to be the hardness. He's a tough little guy and manages to pass some very large stools. So, it appears that he does still have some movement of the bowel. However, I just feel that if I could only make his stool much softer, he may be more comfortable and able to do this on his own. My vet has told me that fiber in megacolon cats will possibly create more bulk where more bulk is not needed. I really need help. I've been looking for answers for years and am becoming frustrated and sad for my cat. No one seems to know much about this and I don't know what to do anymore. I'd really like to stay away from surgery because of his age, if this is at all possible. Thanks for any help you can provide.

A: DL - . The most consistently successful medication for megacolon in our practice has been lactulose (Chronulac Rx and others). An alternative that has worked in some cases is adding pumpkin pie filling to the diet, usually about 2 TBS per feeding. This is increasing the fiber but I disagree with your vet over this - we feel that at times it will work, just not for all cats. I think we posted some information recently on using H2 blockers for megacolon in cats that came either from the Compendium or the Veterinary Information Network (or perhaps both). Your vet may be able to find these references.

I can understand trying to avoid surgery but it is pretty reliable in treating megacolon if medications won't work.

Mike Richards, DVM

Megacolon in cats

Q: Hello- My cat has been having trouble lately with bowel movements. He has been treated in an emergency situation, and well as drugs (Prepulsid), high-fiber cat food, and laxatives (i.e. Petramalt). My vet tells me that this is a case of 'Mega Bowel' (or something like that) where the normal bowel contractions do not occur. I am concerned that my cat is not 'getting better', and that he is in discomfort (until he finally has a bowel movement).

A: There are only two other treatments that I know of for this condition (megacolon) that you haven't mentioned.

Lactulose (I don't know the brand name) is sometimes successful in treating cats with megacolon if the problem is not too advanced. It is a liquid medication and the dosage has to be adjusted to the needs of each individual cat. We have had pretty good luck with this medication.

The other option is subtotal colectomy. This is removal of nearly the whole colon of affected cats. As bad as this sounds, it usually works well. There is obviously a larger surgical risk in this procedure than in most surgeries but it can be the difference between life and death, as well. Your vet should be able to refer you to a surgical specialist who can do this surgery, if necessary.

If your vet is not familiar with the use of lactulose, information is available on the Veterinary Information Network. Or your vet can email me if that is easier. I am not a specialist -- just a general practitioner willing to help another one!

Mike Richards, DVM

Megacolon diet

Q: My British Shorthair female cat who is a year old was just diagnosed with megacolon by our vet. He indicated I should try a 1/2 a tsp of Metamucil in her wet food each day. Is there a special type of food that would be better than regular canned food? A particular brand that might be better for her condition? Is this common to her breed? Is there a cause for this or was she just born with a large colon? Thanks for your help! I love your web page. It is so informative! T.

A: I do not know if megacolon is more common in British Shorthair cats. I have not seen any information suggesting this but there is less breed specific information available for cats than for dogs at the current time.

The current feeling is that higher fiber foods are helpful with this condition. The two highest fiber foods I know of are w/d and r/d by Hill's. There may be others. It is also possible to increase the fiber in the diet by adding psyllium (Metamucil) to the diet or by using pumpkin as a fiber source. A couple of tablespoons of pumpkin mixed with the food is a good source of fiber.

If dietary control is not sufficient, lactulose (Chronulac Rx) and cisapride (Propulsid Rx) are medications that seem to benefit a number of cats.

Most vets start off conservatively, trying to do control the problem without making it too expensive or too much of a hassle. There are a number of ways to deal with this problem and your vet will work with you to change treatment as necessary until the situation is under control. You might also consider surgery (subtotal colectomy) since your cat is so young and this problem often requires lifelong medication.

Good luck with this. Mike Richards, DVM

Constipation in cats (megacolon?):

Q: My cat has trouble getting his stools out. This has been an ongoing problem for about 7 years. He has also had a few urinary tract infections.he has been on docusate sodium for 3 years for his stool problem.I was wondering if you could give me as much information as possible about this?

A: I can't tell you for sure what the problem is in your cat, but I will describe the most likely problem, which is a syndrome known as "megacolon". Megacolon occurs for a number of reasons -- anything that can make it hard for the cat to pass stool long enough to lead to serious constipation. It also occurs for no apparent reason in cats. For whatever reason it occurs, the colon loses its muscular tone and enlarges. Stool size can increase to the diameter of the colon, making it hard for the cat to pass the resulting stools through the bony pelvic canal which does not increase in size. When this happens, the colon becomes impacted and serious secondary problems can occur. Cats are often unwilling to eat, may be depressed, might have a paradoxical liquid diarrhea which is passed in small quantities, vomiting may occur and sometimes there is pain associated with this. Unless the impaction is relieved the cat will eventually die. Many cats have chronic constipation that borders on impaction but never quite gets there. Many of them still have megacolon.

In our practice, we have had the best success in long term medical maintenance of affected cats using lactulose (Cephulax Rx, Chronulac Rx). Some cats will respond to increasing the fiber in their diet using psyllium products like Metamucil or Vetasyl. It is also possible to increase fiber in the diet using canned pumpkin. Surprisingly, many cats will eat pumpkin pretty readily. Cisapride (Propulsid Rx) has been recommended for this problem but we haven't had to use it much and don't have real feel for how well it works. Ducosate products have been the standard of treatment for a long time but we never had a lot of success with them. It's good to see that you have been doing reasonably well with them. When medical treatment fails, or if it is too difficult to medicate a cat chronically, there is a surgical procedure for this condition known as a "sub-total colectomy". Nearly the entire colon is removed in this procedure. Despite the drastic sounding nature of that, the surgery is reported to work pretty well and not to cause chronic diarrhea or other problems that you might anticipate. We have one cat in our practice who has had this surgery and the owner is happy with the results. Hope that helps.

Mike Richards, DVM

Last edited 09/17/02


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...