My female cat has a suspected tumour and fluid build up around stomach and intestine. The vet removed 600ml of fluid a week ago. She was eating very well the last 2 months of this condition, yet gained no wait. The test turned up negative for any illness - thyroid, kidney etc as mentioned above. This last week though, she has eaten virtually nothing. Each type of food once and then no more including medical, salmon (human canned), etc. She nibbled lightly on fresh cooked fish, cheese in last 2 days and drank lots of water. She seems to have an infection in her mouth which has smelled very strong in the last 3 days. Now she can barely stand. As with the other writer here, there seems to be no answers. Before when she was eating, she still had some energy to walk and climb, but gained no weight.