Listing the causes for a cat with a distended or bloated abdomen. I was prompted to write this because of a comment to the page on home treatment for cat constipation page. Hightops, the cat in question has a bloated stomach and is constipated (June 23rd 2012). A blockage in the colon is one reason for a distended abdomen. Chronic constipation might be the cause.
Other possible causes for a distended stomach are:
1. The well known disease toxomplasmosis can cause swelling of the abdomen. This disease is usually asymptomatic (no symptoms in the cat). Other symptoms of a cat suffering from toxoplasmosis are: lethargy, loss of appetite, cough, fever, ‘visual and neurological signs’.
2. Overeating. I won’t elaborate.
3. Eating fermented foods.
4. Worm infestation (kittens).
6. Heart failure.
8. Sudden swelling: Urgent treatment required if there is also pain or discomfort. This can be caused by an intestinal obstruction in the bowel or bladder outlet, abscessed uterus or peritonitis (FIP).
10. Obstruction of urethra (tube that connects the urinary bladder to the genitals). Lower abdomen can be extended.
11. Uterine infection. Pyometra (abscess of the uterus). Inflammation of walls of uterus plus pus in the cavity of the uterus.
12. For kittens toxic milk syndrome causes diarrhea and bloating.
13. Kitten: blood infection. Septicemia. Other signs are straining to defecate.
This is not a comprehensive list but quite extensive.
Source: Cat Owner’s Home Veterinary Handbook.