Colitis is an inflammation of the large bowel (colon). This inflammation may be acute (sudden onset of brief duration) or chronic (long-term), disrupting your pet's normal bowel habits.

Acute colitis occurs commonly in dogs and frequently responds to one to three weeks of therapy. Chronic colitis can go on for several years or perhaps a lifetime.

Many things can cause colitis, from parasitic, bacterial, or fungal infections to inflammatory diseases, allergies, and tumors. In many cases, the exact cause of colitis may never be determined.

Signs of colitis may vary to some degree in their severity. Some dogs and cats may have minor clinical signs; others have severe and sometimes disabling or fatal signs. The inflammation in chronic colitis leads to excess water in a dog's or cat's stool. This is manifested as diarrhea, most likely seen as the frequent passage of small quantities of mucus and/or blood-streaked stools. The diarrhea may be intermittent or continuous. Abdominal pain, depression, fever, weight loss, and a dull coat may also be present.

Your dog or cat should be brought to your veterinarian for an examination if showing any of the above signs. If your veterinarian suspects colitis based on your pet's history, clinical signs and examination, he or she will recommend various diagnostic tests to determine if it is colitis and its exact cause. Then the appropriate medical and/or surgical treatment will be recommended. The important step is to recognize that your pet has a problem and that action can be taken to start a cure or at least make your pet more comfortable.

The writers are Dr. Steven B. Holzman, Dr. William R. Haagenson and Dr. Kathleen Tapley. They are associated with the Nassau-Suffolk Veterinary Hospital of Farmingdale.