Overview of Canine Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome (IBS) is an intestinal disease of humans that involves diarrhea and abdominal cramping of unknown cause. It is not a well-defined disease process in veterinary medicine for dogs and other pets, but is believed to be associated with some sort of functional disorder of intestinal motility or movement, rather than an infectious, inflammatory, or cancerous problem.
It is a chronic (long term) problem with intermittent clinical signs and is primarily a disorder of dogs. There are no breed or sex predilections. Some authors suggest that stress plays a role in the disease process, because IBS has been noted in high strung dogs and performance and working dogs.
What to Watch For
Intermittent bouts of diarrhea or soft stool
Increased frequency of defecation
Passage of small volumes of stool
Straining to defecate
Occasional nausea and vomiting
Diagnosis of Irritable Bowel Syndrome in Dogs
History and physical exam
Complete blood count (CBC)
Fecal tests for parasites, protozoa and bacteria
Tests for bacterial overgrowth in the intestine
Endoscopy and intestinal biopsy
Treatment of Irritable Bowel Syndrome in Dogs
Anti spasmodic/tranquilizer combinations for abdominal bloating and pain
Drugs to minimize gastrointestinal gas
Home Care and Prevention
Give all medications as prescribed by your veterinarian. Careful adherence to dietary recommendations is crucial. Feed only the prescribed diet. Do not feed table scraps or other foods, including natural chew toys (rawhides).
Observe for inappropriate response to treatment or worsening of clinical signs at home. Persistent diarrhea, lack of appetite, abdominal discomfort, and lethargy should prompt a call to your veterinarian.
Because of the possible role that stress may play in this disease process, potential stressors in the home environment should be identified and minimized when possible.
In-depth information on Canine Irritable Bowel Syndrome (IBS)
IBS is thought to be caused by abnormal motility or movement of the intestinal tract. It generally causes chronic and intermittent signs, but the affected animals do not lose weight and otherwise appear healthy. Certain patterns of illness may appear following a stressful event in the animal’s life. The most common signs are bouts of diarrhea and abdominal cramping, bloating or discomfort. There is no specific test to diagnose IBS, so it is therefore a diagnosis of exclusion. This means that all other known causes of gastrointestinal disease that produce similar clinical signs must be ruled out prior to making an appropriate diagnosis of this disease process. Other diseases that may cause similar clinical signs include:
Diseases involving other body systems that have gastrointestinal side effects. These might include diseases affecting the kidneys and/or urinary tract, liver, immune system and endocrine system (hormone producing glands).
Bacterial infection of the GI tract. Campylobacter, Salmonella and Clostridium are types of bacteria that can infect the GI tract and cause diarrhea and vomiting.
Parasitism. Intestinal worms or Giardia (a protozoal organism) can also cause vomiting and diarrhea.
Food allergy or intolerance. Animals that have allergies or an intolerance to certain foods may manifest their allergies via diarrhea and/or vomiting.
Overgrowth of GI bacteria. The GI tract normally contains many normal bacteria; however, excessive growth of the bacteria may lead to an overabundance, which impedes normal GI function.
Inflammatory bowel disease (IBD). IBD is a common cause of diarrhea and vomiting in both dogs and cats. The clinical signs may be very similar to IBS, but it is a different disease. IBD is characterized by the presence of inflammatory cells in the lining of the intestinal wall, as noted by intestinal biopsy.
Fungal disease of the GI tract. Histoplasmosis and Pythiosis are fungal infections that can involve the GI tract and cause vomiting and diarrhea. These infections are specific to certain geographical areas.
Neoplasia. Cancers affecting the GI tract, most notably lymphosarcoma, can cause similar clinical signs as IBS. Lymhposarcoma is a cancer of the lymphoid tissues, of which there is an abundant supply in the GI tract.
Diagnosis In-depth for Irritable Bowel Syndrome in Dogs
A history and physical exam are necessary to guide the diagnostic work-up. Careful history taking should help determine if the clinical signs are consistent with the classical presentation of animals with IBS. Physical exam findings of animals with IBS are usually unremarkable. Abnormalities found on the physical exam may be more suggestive of another disease entity.
Complete blood count. The CBC evaluates the red and white blood cells as well as the platelets. The CBC is usually normal in these patients, but it may be helpful to rule out other disease processes that may cause signs similar to IBS.
Biochemical profile. The biochemical profile helps to evaluate liver and kidney function as well as assessing blood sugar, protein and electrolyte levels (sodium and potassium are examples of electrolytes). This is imperative in ruling out diseases of other body systems such as liver and kidney disease.
Urinalysis. Evaluation of the urine together with the biochemical profile is necessary to fully assess kidney function.
Fecal tests. Fecal analysis is necessary to diagnose bacterial and parasitic infections. A fecal float looks for worm eggs. A fecal culture is necessary to rule out the bacterial causes of infection, and there is a specific fecal test to diagnose Giardia.
Fecal cytology. This involves examining the feces under a microscope to look for evidence of inflammatory cells, which may be indicative of an infectious process or another disease such as IBD. Fecal cytology should be normal in patients with IBS.
Bacterial overgrowth can be assessed in several ways. One method involves getting samples of intestinal juice and culturing it to evaluate the total number of bacteria present. Bacterial overgrowth can also be implied by measuring blood levels of cobalamin (Vitamin B12) and folate. Cobalamin is often consumed by bacteria and folate is a substance produced by bacteria. Therefore, alterations in the levels of these two substances can be suggestive of bacterial overgrowth.
Food trial. Switching the animal’s food to a new diet or a hypoallergenic diet may indicate an allergy to a specific food if the signs resolve following cessation of the previous diet.
Abdominal ultrasound. Ultrasound exam of the abdomen may help pinpoint the site of the problem. Animals with IBS have normal exams. Evidence of intestinal thickening or enlarged lymph nodes or tumors in the abdomen will help exclude a diagnosis of IBS.
Intestinal biopsy. Biopsy of the intestine is necessary to rule out inflammatory and cancerous causes of the clinical signs. This is often done via endoscopy, which is a scope placed into the animal’s intestinal tract either via the mouth or the rectum. Biopsies of the stomach as well as the small and large intestine can be obtained by this method.
Therapy In-depth for Dogs with IBS
Treatment principles for IBS involve manipulating the diet to create a highly digestible food source. Additionally, many animals respond favorably to addition of fiber to the diet. Fiber is thought to normalize gastrointestinal motility. Many animals will not respond to dietary therapy alone and may require anti-diarrheal, anti-spasmodic, anti-gas and even tranquilizing drugs during episodes of marked discomfort.
Dietary modification. A diet that is low in fat and highly digestible is recommended. This should be a diet that the pet has never eaten before. Hypoallergenic diets may also be used. Fiber can either be added to the diet, or high fiber formulations may be prescribed. It is important to note that each animal is different with respect to their response to a particular diet and the dietary modification must be tailored to the individual.
Antidiarrheal drugs. Loperamide (Imodium) and diphenoxylate (Lomotil) are drugs that may be useful in dogs whose predominant signs are diarrhea and urgency to defecate. They work by decreasing intestinal secretions, promoting absorption, and altering intestinal motility. They should be used under the supervision of your veterinarian, as some dogs may have worsening of bloating and abdominal discomfort as a side effect.
Antispasmodic/tranquilizer medications. Librax is one example of a combination drug that may alleviate discomfort associated with bloating. It contains a Valium-type sedative and an antispasmodic agent that reduces intestinal motility. This type of drug is generally used on a short-term basis only.
Anti-gas drugs. Over the counter medications such as Gas-X and Mylanta-Gas contain a drug called simethicone, which alleviates intestinal gas. This is another drug that should only be used after consulting with your veterinarian.
Home Care of Dogs with IBS
Optimal treatment for your dog involves a combination of home and professional veterinary care. Follow-up can be critical, especially if your pet does not rapidly improve.
Administer all prescribed medications as directed. Alert your veterinarian if you are having problems treating your pet.
Strict adherence to a new diet is imperative to successful dietary therapy. The prescribed diet should be the only food that your pet eats. This means that all treats (unless made of the same formulation as the new diet), table scraps and natural chew toys or flavored toys must be eliminated. It is important to notify your veterinarian if your pet is not adjusting to the new diet and is not eating appropriate quantities. Problems with palatability may require changing the diet or even formulating a special home-cooked diet in certain cases.
IBS can be a frustrating disorder because of its chronic and intermittent nature. Flare-ups should be expected. It is important to try to determine if recurrence of signs coincides with any specific activities or changes in your pet’s environment. All possible stressors should be minimized as much as possible.
IBS is not a life threatening disorder and will not shorten your pet’s life expectancy. Careful observations and coordinated care with your veterinarian will allow you to determine the proper therapy for your pet and hopefully minimize flare-ups.
Once a full work-up has been completed, the need for follow-up care will depend on how your pet is doing at home. If signs are becoming more frequent or worsening, repeat diagnostics may be necessary.