Cats with distended abdomens that are losing weight despite an increased appetite are definitely sick. The question is how sick, and what can be done? The answer depends upon accompanying symptoms. A veterinarian will run diagnostic blood, urine and stool tests to determine the cause of the symptoms, and plan an appropriate treatment.
The most common cause of distended abdomen accompanied by weight loss and increased appetite also is the most easily remedied--tapeworms. Because of their habitual grooming, cats are likely to ingest an infected flea, and the tapeworm will take up residence in the cat. The parasite feeds off the nutrients the cat ingests, causing the ravenous appetite and weight loss. If untreated, the worms can grow large enough to form a mass in the cat's abdomen. Tiny, white rice-sized segments in the cat's stool are a telltale sign of tapeworms, which are easily treated with injectable or oral medication.
When the wall of the intestine becomes inflamed, cats can begin to lose weight, begin vomiting and having diarrhoea, and the inflammation can cause the belly to swell. The causes of feline bowel disorders are unknown but genetics, improper nutrition and infections are thought to play a role. Treatment involves switching to a hypoallergenic diet, and medicating with antidiarrhoeal and antibiotic medications.
Feline lymphosarcoma most commonly develops in the intestinal tract, and is a cancer that affects the lymphoid tissues of cats generally between the ages of 2 and 6 years. Cats that have the feline leukaemia virus are more likely than others to develop lymphosarcoma. Although treatment may be extended and difficult, lymphoma usually responds to chemotherapy. Some cats may not be able to tolerate the treatment cycle and may succumb to the disease.
A disruption in pancreatic function can cause increased appetite, distended belly, and weight loss by disrupting the cat's metabolic chemical balance. Diabetes is usually the culprit, especially if increased thirst and urination are present. Pancreatitis also can occur, although most pancreatitis patients have a loss of appetite. Treatment for diabetes involves doing a glucose curve to figure out the appropriate dose for insulin, which the cat will be dependent upon for life. Treatment for pancreatitis depends upon how much damage has been done, and whether the case is acute or chronic.
Cushings disease is a rare disorder caused by an overproduction of cortisol by the adrenal gland, most of the time due to the presence of a small pituitary tumour at the base of the brain. Cushings causes increased appetite, weight loss and a "pot-bellied" appearance; ethargy, bruising and hair loss also may occur. The most effective medication is the surgical removal of both adrenal glands, after which the cat must remain on medication for the rest of his life. Cats that develop Cushing's usually have diabetes as well, and having the adrenal glands removed will change his insulin-dosage requirements. After surgery, the cat must be medically evaluated several times per year to monitor for metabolic changes.