Colitis is an inflammation of
the colon. It is responsible for about 50 percent of cases of chronic diarrhea in dogs. The signs of colitis are painful defecation,
prolonged squatting and straining, flatulence, and passing many
small stools mixed with blood and mucus. These signs can easily be mistaken for
The usual cause of colitis is one of the inflammatory bowel diseases. Whipworms are another frequent
cause. Fungal colitis is uncommon. It targets dogs with immune deficiency and
lowered resistance. Prototheca colitis is a rare disease caused by an algae. It
produces a severe form of colitis and can become systemic. Treatment has not
All forms of congenital heart disease occur
in dogs. The most common defects
are valve malformations (called dysplasias),valve narrowing (stenosis),abnormal
openings between the heart chambers (septal defects), patent ductus arteriosus,
and Tetralogy of Fallot.
Patent ductus arteriosusis a persistent arterial connection between the
aorta and pulmonary artery that normally closes at birth or shortly thereafter.
In the uterus, the ductus plays an important role in shunting blood away from
Colitis is diagnosed by colonoscopy and colon biopsy. Stool specimens are
examined for parasites and fungi.
Irritable bowel syndrome describes a diarrhea motility disorder often
associated with stress. It tends to occur in high-strung, nervous dogs. Dogs
with irritable bowel syndrome have frequent small stools, often mixed with
mucus. The diagnosis is based on the exclusion of other causes of colitis.
Treatment: Treatment is directed toward the underlying condition, often an
inflammatory bowel disease.
Irritable bowel syndrome can be helped by a high-fiber diet (see Constipation).
Bacterial causes of colitis, such as salmonella, campylobactor, and
clostridium, will respond to appropriate antibiotics.
WebMD Veterinary Reference from "Dog Owner's Home Veterinary Handbook"