Colitis in Dogs


Eosinophilic colitis in Boxer - Azathioprine (Imuran Rx)

Question: Dr. Richards, My 4 yr old boxer that has eosinophilic colitis. He is currently taking 5mg prednisone once a day and 500 mgs metronidizole once a day. He does well on this but our vet is doing some research on a drug called Azathiprine that may be a better alternative. She said it is only usually used in cats but research has been done on its effectiveness in dogs. I am hoping you may have info on this drug or can steer me in the direction of where I can find info. The only info I can find on the web is for its use in humans. Thanks, Kim Kim- Azathioprine (Imuran Rx) is used fairly commonly in dogs in combination with prednisone, in an effort to decrease the amount of prednisone that is necessary to control a problem or to add to the effect of prednisone when it is not working well enough. This medication is usually dosed at 0.5 to 1mg/lb of body weight per day in dogs. It is usually given daily for a week or two and then given every other day after that, if intermittent use works. Often, it is given on a rotating schedule with prednisone, so that both medications can be given every other day but the patient is medicated with one or the other drug each day. For some patients, dosages as low as 0.25mg/lb (0.5mg/kg) per day will work. The biggest drawback to the use of azathioprine in dogs is that it causes bone marrow suppression in some patients. It is important to monitor for this effect by checking complete blood counts on a regular basis (usually weekly for two weeks, then the interval is adjusted based on what is found on the initial lab work. Azathioprine can cause liver problems in some patients so checking the liver chemistry values after a week or two on the medication and then at some regular interval would be a reasonable precaution, as well. Like prednisone, azathioprine is an immunosuppressive medication and this means that it is necessary to watch carefully for signs of illness of any kind when a patient is on these medications and report these signs to your vet when or if they occur. Five milligrams per day of prednisone is a pretty low dose. If this works well it does not seem to be a huge risk in a boxer sized dog, even though we would prefer to use it every other day, if possible, even at low dosages. If the condition that your boxer has is the ulcerative colitis problem seen predominantly in boxers, and not something like a food hypersensitivity or other form of inflammatory bowel disease, it is not likely that you will have success with alternate day prednisone unless azathioprine is used in conjunction with it -- and it may take some luck for that treatment to work out OK. Adding sulfasalazine (Azulfidine Rx) as an alternative to metronidazole might work if there is a need to change medications in the future. If this is histiocytic ulcerative colitis, this condition can be hard enough to treat that if you have control of it with what you are presently doing I would be really tempted not to change anything, though. Eosinophilic colitis, if this has been confirmed by biopsy, would be a different situation. It is more likely to respond to non-steroidal medications, such as sulfasalazine and it is more closely associated with parasite infections and allergies than other forms of colitis. So the first step is to deworm, even if worms can't be found on a stool sample. Then trying one of the hypoallergenic diets would be reasonable (Hill's z/d or Purina's HA). If these are not acceptable to your dog, a novel protein diet, such as duck and potato, or salmon and rice, might we worth considering. It is more tempting to try alternative approaches and alternative medications when dealing with this condition, since it is usually less severe and since it is usually possible to re-establish control of the colitis if it is lost, which is not always the case with histiocytic ulcerative colitis. Hope this helps some. Mike Richards, DVM 12/4/2000

Eosinophilic colitis in Boxer

Qustion: Dr. Richards, I have a boxer (~3 yrs) that was adopted a year ago. Jake had been in an animal shelter for 6-weeks and came to us with loose stools and major skin problems. Within a week of owning him, he was put on steroids and antibiotics for his "stress colitis" and a "staph infection", which helped immensely. He was on and off steroids for about two months and then the doctor wanted him off them for 6 weeks to do an ATOPY test. This test came up negative for all allergens. After that, a TLI test was done to rule out liver problems. Tons of blood tests were done. All was normal except elevated white blood cell count. So now it was "food allergies" and "folliculitis", with a little "pancreatitis" and "parasite infection" thrown in. He would constantly break out with big red bumps all over his head, neck, and torso; and his stool looked like pudding. Then came two months of food trials which helped skin somewhat but did not help "pudding poop." After several stool samples and nothing showing up, doc decided Jake may have giardia and put him on Metronidizole 500 mg. After a few days, his stool firmed up and we thought he was all better. Then came the oh-so-horrible blood in the stool. It was pure red and mucusy. Now, this is after 8-10 months of tests that only tell us what Jake doesn't have and thousands of dollars of vet treatments. We were extremely frustrated and completely broke, but back to the vet we went. The vet told us she suspected Inflammatory Bowel Disease and told us we needed to "go inside" and see what's going on in order to confirm her suspicions. We agreed (much to the delight of Master Card) to do the exploratory abdominal surgery the next day. That was exactly two weeks ago and a diagnosis of eosinophilic colitis was confirmed. I was told Jake's ntire GI tract was inflamed, especially his colon. His liver had been biopsied and was in excellent condition, as were his pancreas and gall bladder. Treatment right now includes metronidizole 500 mg (pulsing 2-weeks on, 5-days off) and feeding Innovative Veterinary Diets Rabbit and Potato food. hose 5-days off are met with skin break-outs and pudding poop. The vet wants to start Jake on steroids the first of August. So, on to my actual questions. What exactly is eosinophilic colitis? How bad are steroids for Jake? Would it be better to give oral steroids or injected? Should Jake's activities be limited or is it okay for him to engage in active play (etc. chasing balls, running around, agility training)? Thank you so much for all your help. Kim Answer: Kim - Eosinophils are one of the white blood cells. Control of parasite infections is the major job of this particular white blood cell. Therefore, whenever there are rises in eosinophil levels, parasites should be a consideration. In the case of colitis the parasites most likely to be involved are whipworms. It is considered to be prudent to deworm for whipworms in any patient with chronic colitis, since whipworms do not always shed the eggs used to detect them in the feces, making it possible to miss a whipworm infection on fecal examination. Unfortunately, when eosinophils are not fighting parasites they tend to be involved in the development of allergic responses, including food allergies or food sensitivities, at times. Eosinophilic colitis is colitis that is caused by, or at least has as a symptom, excessive accumulation of eosinophils in the colon lining. This can be due to parasites, food allergies or it can just occur for no discernible reason. Dietary control of eosinophilic colitis sometimes works, usually by using a diet that contains proteins the dog has not been exposed to previously (hypoallergenic diets) or by using an easily digested low fat diet designed to be minimally irritating to the colon. Examples of hypoallergenic diets include the Innovative Diets (tm) that you are already using and similar "novel" protein diets as well as hydrolysed protein diets such as Purina's HA (tm) or Hill's z/d (tm) diets. The usual recommended medical treatment is to try sulfasalazine, metronidazole or prednisone and to treat until at least two to four weeks after clinical signs are completely controlled, then try to taper off the medication. Although there are potential problems with each of these medications the general order of problems from least problems to most problems is metronidazole , sulfasalazine , prednisone. So we usually try these medications in this order but other vets have different preferences, especially since the general success rate is probably exactly the opposite with prednisone , sulfasalazine , metronidazole. It is acceptable to use dietary control and medical control at the same time and to try to sort out which one is helpful over time. Oral prednisone is considered to be safer than injectable corticosteroids for several reasons. It is easier to dose at intervals, a steady state of dosing is obtained instead of the high initial dosage that tapers off when using injections and the medication can be stopped when given orally but once the injection is in the dog you have to wait for the effect to wear off even if severe side effects occur. The side effects of prednisone use include increased drinking and urinating, weight gain, muscular weakness and increased susceptibility to infections. These effects have to be balanced against the benefits, which are strong suppression of eosinophils and inflammation. For many dogs with chronic colitis the benefits outweigh the risks. Once in a while we see a boxer who really seems to have stress induced colitis. These dogs do better if nervousness and stress can be kept to a minimum. Sometimes that means exercising them and letting them work off stresses but sometimes it means avoiding really exciting play times that bring on bouts of diarrhea. You just have to see which category your dog falls into over time. It is a bummer when it takes a long diagnostic process to finally figure out what disease is present. In this sort of disease it is not unusual to go through the steps your vets took to get to a diagnosis, though. Hope this helps some. Mike Richards, DVM 7/31/2000

Lymphocytic/plasmacytic Colitis.

Question: Dear Dr. Richards, Thank you very much for your response. Sammy did have a colonoscopy back in March 2000. The diagnosis was Lymphocytic Proliferative Colitis. It seems that the only way to treat this type of colitis is with 40mg of prednisone along with change in diet. Last week we changed Sammy's diet from Eukanuba Low-Residue to Waltham Select Protien with Lamb & Rice. Our vet along with the prednisone (for six weeks) put Sammy back on metronidazole (for one week) due to a high white cell blood count. His blood test showed his WBC=16.8; Lymphs=7392 and Calcium=12.1. Our question is: is there any other treatment available for colitis? At one point Sammy was given Sucralfate but had a poor reaction so is not allowed to have any sulfar drugs. Our problem is Sammy needs to be taken out every 1/2 hour to an hour to urinate. Because he drinks so much water each time he goes out it is quite a lot (his urine is clear, just about no sign of yellow). Our vet said he felt bad that we have to get up every hour or so through the night but there was nothing he could suggest. We are not sure how to cope with this as my husband and I, along with getting little sleep, are self-employed and need to be away from home 2 to 3 hours at a time which we cannot do now. What do other pet owners do who ave pets on prednisone? Any help you can give us would be greatly appreciated. Again thank you for all your help. Sincerely, Elizabeth Answer: Elizabeth- There are several treatment options for lymphocytic/plasmacytic (proliferative) colitis. It is not entirely clear why this condition occurs. In some dogs food allergy or food sensitivity does seem to play a role in the colitis. For this reason, trying diets made to be hypoallergenic is worth considering. Our experience has been that this is helpful in only a small percentage of dogs with lymphocytic plasmacytic colitis but for the dogs it helps, it is much better than using chronic medications. The lamb and rice diet is an acceptable hypoallergenic diet, as long as your dog has not been fed a lamb based diet prior to this time. Some dogs will improve if fed highly digestible diets such as Hill's i/d, Purina's EN and Iams Low Residue but it doesn't sound like that approach helped. Other dogs respond to moderate or high fiber diets. It is acceptable to use a diet like Hill's w/d or r/d to see if they help or simply to add Metamucil (tm) or another psyllium based product to a food your dog likes and does reasonably well on. The mainstay of medications for lymphocytic plasmacytic colitis has been sulfasalazine (Azulfidine Rx), which is a sulfa based antibiotic. I am wondering if this is the medication that Sammy reacted adversely to, because sucralfate (Carafate Rx) is not highly likely to cause sulfa reactions, even though it does have a sulfa component. I would have to carefully weigh the potential benefits and risks based on experiences with a patient, but I would not rule out trying sulfasalazine based on a previous problem with sucralfate, if the alternative is high dose prednisone use. It would be necessary to proceed cautiously with initial use of this medication, though. Metronidazole is used to treat lymphocytic plasmacytic colitis in many cases, as well. It will sometimes work as a single agent and it will sometimes work to lower the dosage of prednisone necessary to control the problem when multiple drug therapy must be used. If metronidazole will control the problems it can be used long term to do so. Metronidazole is used less commonly than sulfasalazine, probably because it doesn't work as often as a single medication. Prednisone is the other medication that helps to control lymphocytic plasmacytic colitis. It is usually necessary to use pretty high doses of prednisone (2mg/kg per day) for the initial dosing and to continue that for two to four weeks until the colitis is controlled. At that time, the dose should be tapered over time to the lowest effective dosage that can be given every other day. In dogs that are very sensitive to the side effects of prednisone we will sometimes reduce the dosage more quickly, trying to find a compromise between effectiveness and the side effects. It is often possible discontinue prednisone after several months or to get to a very low every other day dosage that controls the clinical signs and limits the side effects. Unfortunately, I know of no way to avoid the side effects associated with prednisone when it has to be used. Most pets on prednisone can still go several hours between urinations (some of our patients manage to go six to eight hours despite being on corticosteroids but have large volume urination when they do go). It might be a good idea to consider the possibility of a urinary tract infection that may be causing the need to urinate frequently, since these are a common problem in pets on prednisone, as well. Antibiotics may help with this situation if it is present. In a situation in which prednisone, or other corticosteroids, caused severe side effects that were simply intolerable, which your situation would be for me, I would consider using cyclosporin (Sandimmune Rx) or azathioprine (Imuran Rx) as the immunosuppressive agent for the colitis. Azathioprine can be used in combination with prednisone to reduce the dosage of prednisone that is necessary. Cyclosporin is used alone. There are no really good studies on the use of cyclosporin in dogs but anecdotal evidence of success with it exists. The dose has to be adjusted to each individual dog based on measurements of the medication in the serum and it is expensive, but it doesn't cause the increased drinking and urinating that corticosteroids produce. You may find that prednisone causes a lot less problems as it is possible to use lower dosages so it may be worthwhile to hang in for several weeks and then consider alternative medications if necessary. Good luck with this. Mike Richards, DVM 7/16/2000

Possible alternative treatment for lymphocytic colitis

Dear Dr. Richards, Question: I had emailed you in mid May regarding our 10 month old puppy who has colitis. The information you emailed back to me was very helpful. Right now Sammy is having an acute attack of colitis and I had a few more questions. My husband and I have kept Sammy on the metronidazole, cimetidine and the Hills I/D canned dog food. We were hesitant in putting Sammy on the prednisone because of the side effects - one being able to have unlimited water. If allowed, Sammy would drink water excessively and has since we adopted him. Our vet never seemed concern about his over drinking and, though not thrilled, said we could limit his water consumption to a point. This meant not leaving water out for him but giving him water through out the day, usually about 8 cups. It seemed cruel to me to not have water available at all times but it became a problem when we were trying to house break Sammy. About three weeks ago I notice that one of the three stools Sammy had per day was slightly loose. From there it progressed slowly to all stools being loose and then since last Wednesday full blown diarrhea. For some reason the metronidazole no longer worked. We took Sammy to our vet that Wednesday and he put Sammy on 40 mg of prednisone per day. He is also changing Sammy's diet to Waltham. It is now Monday night and Sammy still has diarrhea. I called my vet and he said to continue on the prednisone (6-8 weeks: 2 weeks at 40mg, two weeks at 20mg; two weeks at 10mg & then 5mg every other day) and give him loperamide for the diarrhea. My question is, are there any other possible alternative treatment for lymphocytic colitis? I know this is going to sound extremely selfish but we need to let Sammy out every hour to urinate because of the unlimited water (our vet said any restriction on water would cause kidney damage). It wouldn't be bad if it was just for a week but the course of treatment is six weeks possibly more. My husband and I take turns getting up through the night but we are still exhausted. Our house is such that there is no room Sammy can be confined to without causing damage from the urine/diarrhea. Outside is not an option for a number of reasons, one of which is the heat. If it was our home, a damaged room would not be an issue but it is not our home, we are renting. Our vet also told us that just about anything can bring on an attack, i.e. weather change, any kind of stress etc. We are trying not to panic but the long term quality of life doesn't look good. Are there puppies that have been diagnosed with colitis and lived a normal, basically healthy and happy life? Any information you can give us would be very much appreciated. Thank you, Elizabeth Answer: Elizabeth- There are many puppies with colitis who live relatively normal lives. This is especially true for puppies in which the colitis is related to food allergy or hypersensitivity. In a pet this young, a systematic work up to identify the cause of the colitis may prevent a lot of long term cost and discomfort for the puppy. It is good to review the history and try to be sure this is a large intestinal diarrhea (usually small stools on a frequent basis with some urgency about them) versus a small intestinal diarrhea (usually normal to large volume stools that may be nearly liquid to nearly formed and normal bowel movement frequency, such as two to three times a day). There is some overlap in these symptoms, though. I do not know which Waltham diet you are referring to but if it is a hypoallergenic diet that would be a good start in the diagnostic process. Most puppies with food allergy as a component of their problem show some improvement on these diets within three weeks but it may take two months or more to get total resolution of the problem. It is also a good idea to check for pancreatic insufficiency, which can be done by testing for trypsin-like immunoreactivity in the serum, a test that some commercial labs now offer. Testing for serum folate levels may also be helpful. Checking for parasites in the stool and/or deworming on the suspicion they might be there are good procedures, too. After that, examination of the gastrointestinal tract by endoscopy and obtaining biopsy samples would be a good idea. This does sometimes get expensive but it still often results in much less expense over the life of the dog, especially one starting with problems at such a young age. Hope this helps some. I am sorry for the delay. If diagnostics are not possible there are some other treatment alternatives. The first one I usually try in large intestinal origin chronic diarrheas is azulfidine, an antibiotic that is meant for long term use and is often helpful. You can not restrict water while using azulfidine, though. Tylosin is another antibiotic that sometimes works well for chronic diarrhea. It is better to do the diagnostic approach then treatment rather than the other way around, though. Mike Richards, DVM 7/3/2000

Colitis that is recurrent in Akita

Question: I first want to thank you so much for all the advice you have given us in the past. It is so helpful to have a "second opinion"on what is going on with our dog. To recap the latest - we have a male neutered Akita who is almost 10 years old. He has a history of seizures of unknown origin for which he takes phenobarbitol and potassium bromide. This combo seems to work. In addition, he has been recently taking a medication called PPA for incontinence which sort of works. Our problem now - he seems to have a case of colitis ( at least this has been the diagnosis from our vet) that comes - is taken care of with a medication called sulfathalazine ( I'm not sure of the spelling) - but then comes back within a week of stopping the medication. The last time we gave it to him we stopped after only a day. The vet said it was OK to do that - to treat the symptom and stop when the stymptom stops. I'm wondering if this is the problem - that we stopped too soon, like an antibiotic. He's showing the same problem again - he squats as if to go but really there's very little there. He does this off and on all day. Is this colitis? Should be not stop the medication? What do you think is going on? Thank you so much in advance for all your advice. I look forward to hearing from you. Louise for Major Answer: Louise- It is not unusual for colitis to return when medications are withdrawn. There are some dogs that require lifelong administration of medications like sulfasalazine to control colitis. However, I tend to want to try to stop the medication occasionally, just to be sure it is necessary. Usually it is a good idea to continue sulfasalazine for at least a couple of weeks after colitis seems to be controlled. Then gradually stopping the medication over two or three days is advisable, so that it can be restarted if there are signs that the colitis is returning. If it becomes necessary to use sulfasalazine on an intermittent basis (two or three months of the year, for instance) it is OK to do that, in my opinion. It might be worthwhile to consider an endoscopic examination of Major's colon, if that can be arranged. If this is done and no obvious problem is found, biopsies of the colon wall taken during the exam might still be helpful in identifying a cause that can be treated more specifically. The basic answer to your question is that I agree with your vet that using sulfasalazine intermittently is OK and that frequent small bowel movements with lots of straining is suggestive of colitis but doesn't give much information on the cause of it. If there stops being a response to medication it would definitely be a good idea to consider a colonoscopy exam. Good luck with this. Sorry for the delay in responding to your question. Mike Richards, DVM 5/24/2000

Treatment for Colitis

Question: Dear Dr. Richards: What is the best treatment for Colitis or IBD. Our puppy Sammy was diagnosed with this disorder in February 2002. Sammy is a 8 month old Golden Retriever. We adopted him the beginning of December and in January he started having the runs. He was tested for worms but was clear. Our vet put him on Metronidazole and within days he improved but as soon as he completed the treatment (at first 7 days, then 14 days, 21 days and currently 60 days) the diarrhea returned. To make certain of the diagnosis our vet suggested Sammy have a colonoscopy. He did and the diagnosis was confirmed. About a month ago in the mornings we would find that Sammy had thrown up during the night. The vomit contained no food only bile. Our vet then prescribed 200mg of Cimetidine to be given 4 times a day (the Metronidazole is 500mg given at breakfast and dinner). Once the diagnosis was confirmed the treatment prescribed was prednisone and Eukanuba Low Residue Canine (adult) diet. We changed over from the Canine I/D to the Eukanuba but decided to stay with the Metronidazole instead of the Prednisone since the Metronidazole seemed to be working. My questions: 1. Are we doing the right thing and how long can he stay on the Metronidazole and Cimetidine without long term effects. We looked into natural remedies (i.e. shark cartilage) but our vet advised against it. Sammy has had all his vaccinations and has been neutered. He is overall a healthy and active puppy. Only when he was taken off the Metronidazole did he loose weight (I think mostly from the diarrhea). He previously had never lost his appetite until now. He doesn't seem to want to eat at breakfast unless we hand feed him. He has walked away from his lunch and dinner a few times but mostly it's breakfast. Because he will eat when we hand feed him we were not concerned but should we be? 2. Sammy loves to go in the water. How long after Protocol is applied should we refrain from letting him in the water? We have started applying the Protocol weekly instead of monthly as per our vet's advice. Sammy had gotten two ticks when he was 4 months old (he was tested for lime disease, the results were negative) which were imbedded and needed to be removed by our vet. A few weeks ago I removed a tick from his chest area. I check him everyday for ticks (we live on Long Island where deer ticks are rampant) so this tick was not there long. Our vet said because Sammy goes in the water we should apply the Protocol weekly. Any advice you can give us would be greatly appreciated. Thank you. Sincerely, Elizabeth Answer: Elizabeth- Metronidazole is used very long term for some conditions and it doesn't seem to cause problems with long term use. Some cases of colitis are due to food sensitivities. To find out if this is the case, a trial diet consisting entirely of ingredients that your dog has never eaten before can be fed for several weeks ( at least 3 weeks, preferably 6 to 8 weeks). A number of commercial diets are made for this purpose, including Purina LA and HA (tm) diets, Hill's d/d (tm) diets, Innovative Diets (various types, such as duck and potato) and Waltham Limited Antigen (tm) diets. It is possible for a food sensitivity problem to clear up with antibiotic use but it is less likely to so than other immune mediated colitis problems. There are several types of immune mediated chronic colitis in dogs. lymphocytic/plasmacytic colitis, eosinophilic colitis, histiocytic-ulcerative colitis and granulomatous colitis are some of the names of these conditions. If you know the exact diagnosis I will be glad to try to review specific treatment options for you. The two most commonly recommended medications for immune mediated colitis are sulfasalazine (Azulfidine Rx) and prednisone. Sulfasalazine is recommended most commonly for lymphocytic/plasmacytic colitis and prednisone for eosinophilic and granulomatous colitis. It is acceptable to use metronidazole (Flagyl Rx) as a substitute for sulfasalazine and tylosin also works sometimes. If it works, dietary control of colitis is best, because side effects are not likely. After that, using the medications that work is the best approach. Since you and your vet have found a combination of medications that work, I'd want to go with that approach until it didn't work or until enough time had gone by with control of the diarrhea that it seemed reasonable to cut back on the medications to see if the problem had resolved. Your vet can help you figure out when it might be reasonable to do that. Good luck with this. I am willing to try to give you a little more detail on the type of colitis that is affecting your dog if you can find out what it is. Mike Richards, DVM 5/22/2000


Q: Hi Dr. Mike - My 3 year-old Welsh Terrier has been diagnosed with colitis. She is now eating W/D dry food which has helped immensely. However, she still has bouts of stomach problems approximately every 4 days. Like clockwork, she wakes up and will not eat (the night before having been 100% normal). She is lethargic that day, refusing food, and then vomits in the late afternoon or early evening. The vomit is clear, foamy; occasionally there is diarrhea. Then her appetite returns and the next day she is perfectly normal again. She takes elavil 2x/day and seldane 1x/day. The vet says the only other thing to do now is endoscopy. I am reluctant and wonder what you think. What could this habit indicate ? Should I be concerned and have the endoscopy performed ? Or should I just look at it as her idiosyncratic eating habits and relax ? I really appreciate your opinion. Thank you ! A: MJM- I might not worry about this situation if your terrier was just skipping meals once a week or so, but vomiting and occasional diarrhea do indicate that there is a problem present. If intestinal parasites have been ruled out by labwork and if bloodwork is normal or at least does not seem to indicate a specific problem, endoscopy is a reasonable step to take. It can provide a great deal of information and specific diagnoses. Given your dog's young age that may provide a lot of future relief from this problem. There are other approaches to consider, such as hypoallergenic food trials, X-rays (perhaps using the new BIPS capsules that help evaluate intestinal motility) and testing for specific problems indicated by labwork, such as liver disease (if there is an indication to do this). Intestinal endoscopy and biopsy is a effective tool for aiding the diagnostic process in intestinal diseases, though. Mike Richards, DVM


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...