Chronic Diarrhea in Cats
Dr. Bari Spielman
Veterinary care includes diagnostic tests and subsequent treatment recommendations. Some, if not all, of the following tests may be necessary to diagnose the cause of chronic diarrhea: Complete medical history and physical examination are helpful in instituting an appropriate diagnostic plan.
Multiple fecal studies (flotation, smear and cytology, zinc sulfate test) to search for intestinal parasites, protozoal parasites, and bacteria should be performed on all patients with chronic diarrhea.
A complete blood count (CBC) evaluates the animal for infection, inflammation and anemia.
A biochemical profile assesses kidney, liver, and pancreas function, as well as electrolyte status, protein levels, blood sugar, etc.
A urinalysis helps to evaluate kidney function and the level of hydration of the animal.
A thyroid test is indicated in older cats with chronic diarrhea to search for hyperthyroidism, which results from production of too much thyroid hormone.
Abdominal radiographs (X-rays) assess the abdominal organs and may detect the presence of a foreign body, obstruction, or tumor.
Thoracic (chest) radiographs are recommended in geriatric patients and animals who may have cancer, to detect metastasis (spread of cancer) to the lungs.
Bacterial fecal cultures may be recommended in some cases.
Serologic tests may be performed for viral and fungal diseases that cause chronic diarrhea.
Depending upon the clinical signs and the results of the above tests, your veterinarian may recommend further testing. These tests are chosen on a case-by-case basis:
Serum trypsin-like immunoreactivity (TLI), serum folate, and cobalamin are blood tests that help assess digestion and absorption within the small intestines.
Abdominal ultrasonography helps to evaluate the size, shape and consistency of the abdominal organs. It may detect thickening of the intestines, masses, partial obstructions and other organ abnormalities. Abnormal organs, lymph nodes and masses may be sampled with a needle or biopsy instrument with the guidance of ultrasound. This test may require referral of your animal to a veterinary specialist in internal medicine or radiology.
An upper gastrointestinal (GI) barium series helps assess the passage of food stuffs through the upper intestine. A barium enema helps assess the lining of the lower bowel. The two tests may detect motility disorders, thickening of the bowel, twisting or displacement of the bowel, obstructions, strictures and masses of the intestines. They may also be helpful to detect foreign bodies that are not seen on plain radiographs.
Endoscopic examination and biopsy are often required for diagnosing the cause of chronic diarrhea. Endoscopy involves passage of a flexible viewing scope into the stomach and small intestines. Colonoscopy involves passage of either a flexible or rigid scope into the rectum and colon. Small biopsies, as well as samples for cytology and culture are obtained through the scope
A blood lead level may be performed on cats with chronic intestinal signs, especially if their environment is suggestive of exposure to lead, if there is material showing up on plain x-rays that resembles lead in the intestines, or if certain characteristic changes of lead poisoning are seen on the complete blood count.
Serum bile acid tests may be performed in animals with evidence of liver disease.
Exploratory abdominal surgery (laparotomy) is often considered if other diagnostic tests are inconclusive, or if a disease is suspected that requires corrective surgery. It is sometimes needed to reach a conclusive diagnosis.
Symptomatic or empirical treatment may be tried in some cases of chronic diarrhea, especially if initial diagnostic tests are inconclusive and the animal is feeling well and relatively stable. Empirical treatment does not replace the need to define the exact cause of the chronic diarrhea, it at all possible. Empirical treatment may include one or more of the following:
Deworming for intestinal parasites, which do not always show up on routine fecal tests
Short course of antibacterial sulfa drugs for coccidiosis and trichomonads, especially in kittens and young cats
Changing the diet to a high-fiber diet if large bowel diarrhea is present or to a hypoallergenic diet if small bowel diarrhea is present
Supportive therapy for ill, malnourished and unstable patients may involve hospitalization with intravenous fluids, and supplemental nutrition and vitamins.
Plasma transfusions and infusion of other dense fluids may be required for animals with low protein levels.
Intestinal protectants, antacids, and antivomiting drugs may be administered while results of diagnostic tests are pending, etc.
Motility modifiers (medications that effect he movement of food through the intestinal tract) may be tried in some cases.
Specific therapy of most cases of chronic diarrhea depends upon reaching a definitive diagnosis as to the cause, and then instituting therapy for that cause. Such therapy varies widely and can involve medications, dietary changes and surgery:
Deworming agents are required for intestinal parasites.
Products used for protozoal parasites include sulfa drugs for coccidiosis and metronidazole for giardiasis.
Antibiotics are administered for bacterial infections, small intestinal bacterial overgrowth, and some forms of colitis.
Antifungal drugs (e.g. ketoconazole, itraconazole) are given for fungal infections.
Corticosteroids and dietary manipulation may be necessary for inflammatory bowel disease, lymphangiectasia, and other immune-mediated inflammatory disorders.
Dietary manipulation is helpful in cases of dietary intolerance, food allergy, colitis, short bowel syndrome, and irritable bowel syndrome.
Chemotherapy, radiation therapy or surgery may be helpful in certain cases of cancer.
Surgical exploratory is indicated to correct causes of chronic obstruction, intussusception, cecal inversion, remove foreign bodies, etc.
For some diseases, especially the viral infections, no specific therapy exists and supportive therapy is the primary treatment.
Intravenous fluid therapy and specific treatments for any liver and kidney disorders may be indicated.
Motility modifiers (medications that effect the movement of food through the intestinal tract) may be helpful in cases of irritable bowel syndrome.
Supplementation with cobalamin, folate and other vitamins is often required in the malabsorption/maldigestion diseases.
If lead poisoning is diagnosed antidotes may be started either orally or by injection.
Keep in mind that the resolution of chronic diarrhea is usually gradual with treatment. In a few cases, despite a correct diagnosis and proper therapy, diarrhea may not completely resolve or may worsen, especially in patients with cancer.
It is important to monitor your pet closely if he/she has chronic diarrhea. Pay particular attention to stool volume and character, the frequency of defecation, and any straining to defecate. Note the presence of any blood or mucus in the stool. Also monitor the cat's body weight, appetite and activity level.
Administer all prescribed medications exactly as ordered by your veterinarian. Notify your veterinarian if you have any problems medicating your pet.
Repeated follow-up examinations, fecal tests and blood tests may be needed to bring the chronic diarrhea under control and prevent it from returning.