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Digestive Disorders in Dogs

Also see these articles:

Disclaimer: I am not a veterinarian, nor do I have any formal training in any medical field. The information presented here is not meant to replace your vet's advice or prescribed medications, but only to suggest additional options to explore, based on your dog's condition.

Diarrhea (occasional or short-term)

See your vet if your dog has diarrhea accompanied by black, tarry stools or stools with a lot of fresh blood, loss of appetite, frequent vomiting, lethargy, bloating, signs of pain, or if the diarrhea lasts for more than two days. For occasional diarrhea with no other symptoms, try these remedies:

If diarrhea continues for more than a couple of days, or if it is accompanied by other symptoms, such as vomiting, see your vet for more help. Diarrhea can cause dehydration and may be a symptom of a more serious problem. Your vet also has access to more potent anti-diarrhea medication, if needed. See the following articles for more information:

The suggestions above are meant to help with occasional problems, not severe or chronic diarrhea. For those, see the section on IBD, IBS and Colitis below.

See GI Disorders: Part 3 – Management of Acute Cases for additional information.

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IBD, IBS, Colitis and other GastroIntestinal Disorders

IBD (Inflammatory Bowel Disease), IBS (Irritable Bowel Syndrome, which is caused by stress) and Colitis (inflammation of the lower bowel) can cause frequent diarrhea and be quite debilitating, even to the point of being life-threatening. These conditions can be difficult to manage and get under control.

IBD cannot be accurately diagnosed without a biopsy, but there are certain symptoms that will help you determine whether your dog is suffering from large bowel (colitis) or small bowel diarrhea, which can help you decide what the most likely cause may be and what treatments are apt to work. For example, small bowel diarrhea is more likely to be caused by bacterial infection or EPI (see below). See Chronic Diarrhea in Dogs for a description of the differences between the two, and an overview of the possible causes. Also see Colitis FAQ for in-depth information on this topic. A 2019 veterinary article, Gut check: Practical treatment of inflammatory bowel disease, provides some technical information on how treatment for this disease is changing.

Update: Antech announced that they have developed a blood test for IBD that can be used for both diagnosis and monitoring response to treatment. The test is expected to become available in the second quarter of 2020. See Antech completes final study of first diagnostic for inflammatory bowel disease for more information.

It's a good idea to treat presumptively for parasites to rule them out as a cause, as some can be very difficult to detect on a fecal exam (whipworms in particular are hard to find). Panacur (Fenbendazole) is a very safe drug to use that is effective against most intestinal worms, including whipworms, as well as giardia. It will not work for coccidia, unfortunately, but the drugs needed to treat that are stronger and I wouldn't encourage using them without a definite diagnosis. I know of people who have spent months trying different diets and supplements to try to help their dogs with chronic diarrhea, only to find out that the cause is parasites and treatment with either Panacur or Albon (for coccidia) clears the problem up quickly.

Although there are many causes of chronic diarrhea, one factor that I've seen come up over and over again is an intolerance for grains in the diet. Many dogs that are switched to a grain-free raw diet do very well, often better than they have in their entire lives. In general, you want to stay away from all grains and other starchy foods that take a long time to digest, such as potatoes and corn, limit the amount of fiber (from vegetables), and avoid dairy, to see if that helps. See below for more info on fiber.

Carrageenan, an ingredient used as a thickening agent in many canned foods, has been associated with intestinal ulceration, inflammatory bowel disease (IBD), and acid reflux. While most studies have been done on carrageenan, it's possible that other thickening agents, such as carboxymethyl cellulose, polysorbate 60 and 80, guar gum, xanthan gum, and agar agar, may also contribute to digestive problems in sensitive dogs. Look for stews and other more liquid (not formed into a pâte or loaf) canned foods to avoid these ingredients. See the following for more infomation:

Problems with grains may be related to food allergies, or to difficulty digesting carbohydrates, or to gluten intolerance. Sources of gluten include wheat (including Kamut and spelt), barley, rye, and triticale; oats are considered questionable (oats are gluten-free but processed oats can be contaminated with gluten), while buckwheat, corn/maize, and rice are gluten-free. Dogs with gluten intolerance may also react to dairy products and to soy. Grains can contain molds or storage mites that can cause an allergic reaction as well.

Chronic pancreatitis may be a cause of diarrhea, particularly if vomiting, anorexia (loss of appetite), or abdominal pain is also present, but symptoms may be as subtle as not wanting to play or skipping meals occasionally. There's a blood test your vet can do to find out whether pancreatitis is contributing to your dog's problems called the Spec cPL.

Many dogs with IBD, chronic pancreatitis, or other gastrointestinal problems have difficulty digesting fat and may need a low-fat diet. See my article, Healthy Low-Fat Diets for Dogs, for more information.

Some dogs with IBD may do better avoiding certain carbohydrates called FODMAPs. More information on which foods should be avoided, and which are OK, can be found at the following human-oriented sites:

Exercise may help some dogs with IBD, particularly if they are otherwise sedentary and get little exercise. See Exercise Helps Dogs with Inflammatory Bowel Disease for more information.

For IBD, colitis, and other forms of gastric irritation, here are some supplements that may help:

See the human-oriented article on Gastrointestinal Repair Nutrients for some additional information on supplements used to help heal the digestive tract.

See my post on Inflammatory Bowel Disease that discusses a recent veterinary conference Update on Inflammatory Bowel Disease, which talks about diagnosis and treatment for some additional information, including mention of using Budesonide (Entocort® EC) in place of prednisone when immunosuppressive drugs are needed, as it has fewer side effects and may be more effective.

An article on off-label use of drugs talks about how the anti-depressant bupropion (Luvox, Wellbutrin) may help people with ulcerative colitis (see This is why a third of antidepressants are prescribed for something else). I don't have a clue if this would work with dogs, but it might be worth trying. I was unable to find dosage information other than that dosages at ten times the amount used for humans caused seizures and other problems in dogs. Your vet, or a veterinary behavior specialist may know more. If anyone tries this, please let me know the result.

Here are links to more information on IBD, IBS and Colitis, as well as some other causes of chronic diarrhea:



Allergy Testing:

Gas (Borborygmus):

More technical:

There is an email group often recommended for people whose dogs have IBD, but it requires a definitive diagnosis of IBD to join: IBDogs


See Exocrine Pancreatic Insufficiency for more information on EPI.

Diarrhea and other stool problems can also be caused by diseases such as SIBO (Small Intestine Bacterial Overgrowth) and EPI (Exocrine Pancreatic Insufficiency). SIBO can be related to IBD.

Symptoms of SIBO include loud stomach noises, lots of gas, increase in stools, often mushy, and many times, DECREASED appetite and loss of weight. SIBO may be linked to a Vitamin B12 (Cobalamin) deficiency, which occurs due to problems absorbing this vitamin, not due to dietary deficiency. It is treated with B12 injections, and usually with Tylan (tylosin), an antibiotic powder, or Oxytetracycline. Antibiotics must be given for 4 to 6 weeks to be effective. Tylan is very bitter, so is best given in capsule form. It is expensive, but you can find it cheaper in bulk and just put it into capsules yourself using an inexpensive capsule maker (apparently the 00 size capsule holds 1/4 teaspoon). Additional treatment should include probiotics, and may involve feeding a low fat diet and/or a novel protein diet, if food sensitivities are suspected. L-glutamine might also be helpful in repairing the intestinal mucosa (give 500 mg per 25 lbs of body weight). In German Shepherd Dogs, SIBO may be a primary condition, but in other breeds, it is considered secondary to other gastrointestinal conditions, such as IBD, EPI, delayed intestinal transit due to partial obstruction or other causes, food sensitivities, etc., so it is important to find and treat the primary condition, and not just the SIBO. The most common test for SIBO is a blood test sent to the GI Lab at Texas A&M. It is a Cobalamin (B12) & Folate test (dogs with SIBO usually, though not always, have low Cobalamin and/or high Folate). If you run these tests, it makes sense to also run a TLI (for EPI) because if the results of the B12 or folate are off they are going to tell you to first rule out EPI (see below for more info on EPI). Go to Texas A&M University (TAMU) GI Lab to read about these tests (see the Research tab).  Dogs are required to be fasted 12 to 18 hours before the test. Note that B12 injections are colored red and may cause the urine to be a reddish color. See Bacterial Overgrowth in Dogs-More Common Than You Think for more info.

Symptoms of EPI include INCREASED appetite; huge fluffy, smelly, gray or yellowish stools (often described as "cow patty stools"); frequent defecation; weight loss; gas; and loud stomach noises (called borborygmus). The dog's pancreas doesn't produce enough digestive enzymes to break the food down and therefore no matter how much they eat, they can't digest their food and therefore they are literally starving. Loss of weight can be rapid. EPI is most common in German Shepherd Dogs, but occurs in other breeds as well. Dogs with chronic pancreatitis have an increased risk of developing EPI. A blood test called TLI (trypsin-like immunoreactivity) is used in combination with tests for Folate and Cobalamin to confirm a diagnosis of EPI.

This condition is treated with prescription powder enzymes, such as Viokase. Viokase is hundreds of times more potent than the standard digestive enzymes you would find in a health food store. Viokase is very expensive, but there are generic equivalents such as Bio Case that are a little cheaper (see below). Once your dog is stabilized, you can also try reducing the dose to see if the improvement can be maintained with less, as dosage needs often decrease over time.

Alternatively, raw cow or pig pancreas can be used to supply digestive enzymes; see this article on Exocrine Pancreatic Insufficiency for more information. See the sections on Frozen Raw Food Products and Raw Food Co-ops and Local Groups for help finding a supplier in your area (companies that supply parts may be able to get you pancreas even if it is not in their product list). You can also talk to butchers, ranchers and livestock processors in your area to see if they can supply you with raw pancreas.

See Gastrointestinal Function Tests  in Dogs and Cats for more info on interpreting the results of TLI, folate and cobalamin tests. See Chapter 1, Exocrine Pancreatic Insufficiency, for detailed, technical information on EPI diagnosis and treatment.

Note that Medium Chain Triglycerides (MCTs) may be easier for a dog with EPI to digest. Studies show that digestions of MCT fats in dogs with EPI is reduced only by about 25%, while digestion of long chain triglycerides (LCTs) is reduced by about 95%. MCTs are found in milk fat and in coconut oil. See Use of Medium Chain Triglycerides in Clinical Nutrition for more information on this topic. Note that when supplementing with coconut oil, you should use virgin (unrefined) oil in glass jars. You can give as much as 1 teaspoon per 10 lbs of body weight daily, but start with less and build up.

Low-fat diets are traditionally recommended for dogs with EPI, but surprisingly diets with 43% calories from fat have been shown to promote better protein, fat and carbohydrate digestibility compared to diets containing 18% and 27% calories from fat in dogs with experimental EPI. Another study failed to show any significant benefit of severe fat restriction (13% of calories). These observations suggest that feeding a higher fat and thus more energy dense diet could promote a rapid restoration of optimal body weight without recourse to medium chain triglyceride oil. However, I would exercise caution when increasing the amount of fat in the diet, as dogs with EPI may also have fat intolerance, so increased levels of fat may lead to diarrhea in some dogs.

Dogs with EPI will benefit from a low-fiber diet, regardless of the amount of fat in the diet. See below for more info on fiber.

Also note that there are studies, including one in the publication above on MCTs,  showing the bacterial lipase works better for dogs with EPI than pancreatic lipase, and is supposed to be less expensive. Unfortunately, all I can find on this are studies, not products. If anyone knows of any bacterial lipase products, I would appreciate it if you would let me know.

Links to more info on EPI, SIBO, and their treatment:

There is a new forum and an email group for people with dogs that have EPI:

Addison's Disease

See Addison's Disease: The Great Pretender, the article I wrote with CJ Puotinen, for more information.

Non-specific gastrointestinal signs are a common indication of Addison's Disease, even if electrolytes (sodium and potassium) are normal. These signs may include vomiting, diarrhea, inappetence, dark tarry stools (melena -- approximately 15-20% of dogs with Addison's will have this symptom) or blood in the vomit, especially if symptoms improve when the dog is given fluids and corticosteroids such as prednisone, then later worsen again. Five percent of dogs with Addison's may have acute gastroenteritis resembling Parvo or HGE (Hemorrhagic Gastroenteritis).

Dogs that appear to be in acute renal failure (high creatinine and BUN, with low urine specific gravity) may also have Addison's Disease. Low cholesterol, low protein (globulin and albumin), and elevated liver enzymes may point to Addison's Disease.

Hypoglycemia (low blood glucose), or hypercalcemia (high blood calcium)  may also be signs of Addison's; in fact, one person who knows a lot about Addison's, says, "I have yet to see an Addisonian (Primary/Typical, Primary/Atypical or even Secondary) who did not have a very low glucose reading prior to being medicated."

A sick dog with a normal or elevated lymphocyte count may have Addison's. Signs of weakness and even collapse that come and go point strongly toward Addison's disease.

Low sodium and high potassium resulting in a sodium:potassium ratio of less than 27 is a classic sign of Addison's disease, though they cannot give a definite diagnosis, and normal values do not rule it out. The definitive test for Addison's Disease is called an ACTH Stimulation test, where blood cortisol levels are measured before and one hour after receiving an injection of synthetic ACTH hormone. Low initial cortisol and little or no reaction to the ACTH indicate Addison's disease.

One of the medications used to treat Addison's Disease is called Florinef. It is expensive when purchased from your vet, but you can get it for much less from compounding pharmacies. Compounding pharmacies can also provide a liquid version which may be easier to get the proper dosage, especially for small dogs. Here are some compounding pharmacies that offer Florinef:
Tiffany Natural Pharmacy (recommended by people on the K9Addisons list)
Florinef for less lists a number of pharmacies that offer compounding for Florinef

Percorten-V (desoxycorticosterone pivalate or DOCP) is an injectable medication given approximately every 25 days. It is the preferred treatment, as it is easier to get dogs stabilized and keep electrolytes normalized than with Flornef. Once the appropriate dosage has been identified, you can save money by learning to give the injections at home. Percorten-V can be purchased from 1-800-PetMeds, who will match any lower price you find.

Please see the following sites for more information on Addison's Disease in dogs:

Addison's Disease: Uncommon or Underdiagnosed?
Addison Dogs
Canine Addison's Info
Addison's Disease (Hypoadrenocorticism)
Addison's Disease (includes links to more info)

There are two email groups for people whose dogs have Addison's Disease:AddisonDogs and K9Addisons.

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Rocky is a Yorkie-Poodle mix who had suffered from digestive problems his whole life. Click on his image to read about the diet his owner finally found to help him.
Pashoshe Fisher, a Chihuahua, was a wonderful, joyful companion to his owner for 19 & a half years. He was on a high quality raw diet for over half his life.
This is Ella, my Norwich Terrier.