Based on the answers you provided, the Web-DVM Symptom Checker has determined that the following are possible causes for your cat’s distended abdomen. Please read the Web-DVM articles for more information on these diseases. Not listed but a possible cause for distended abdomen at this advanced age, is a mass growing from an intra-abdominal organ. Masses can be benign (not cancerous) or malignant (not cancerous) in nature. If you still seek further information, please visit our Ask The Vet page to submit a one on one consultation with a licensed veterinarian 24 hours a day, 7 days a week.