chronic cat flu

Question
Hi,

I have a 14 months old persian male cat (not neutered). When he was about 7 months old, he was diagnosed for chronic flu. The thing is that he always enjoyed food and had a normal weight even with the flu. Recently, his appetite decreased and I noticed that he doesn't poop as he used to. There are also changes in his behaviours; I used to have no trouble grooming him or giving him a bath. Now, it is impossible to do so. He started hissing at strangers and sometimes at me. I noticed also that sometimes his pupils would be larger than normal, that even somtimes they would enlarge in a way that freaks me out!! He does not seem depressed or anything. He's is still active but what worries me that under that thick coat is a very thin body. I can feel his ribs and hips very easily. His current weight is around 3.45 KG.
Also, every once in a while he would get severe diarhea.
Something strange happened today; while I was struggling to give him a deworming solution with a syringe, he suddenly started drooling a bubbly pinkish substance more than 3 inches long!! He kept on running around himself nervously for about 5 mins until the drooling stopped.
What is wrong with my cat? how can I get him to eat more food? I tried eveything.. The only thing vets in my country would tell me is that he has chronic flu!! They keep on injecting him antibiotics but with minimal results. I am starting to think that he might have herpes or calici!!
Please any advice would help! I don't know what to do. Vets here are not helping me much! I already spent more than $500 trying to find a cure for him.

BTW, I feed him royal canin dry food, and I use revolution on him every month since he was a kitten.

Answer
Well neutering him would help with his attitude, that's for sure. He is acting like a tom cat- nasty!
I don't know what chronic flu means- does he have leukemia? Does he have a respiratory illness? Cats don't get 'chronic flu'.
They get viruses like Leukemia which are persistent and eventually fatal. They get FIV, feline Immuno-Suppressant Virus, which is like AIDs in humans.

So you need to get a better diagnosis from this vet. The symptoms you mention, weight loss, disproportionate pupils, diarrhea, are all hallmarks of cats with Leukemia.

Herpes is certainly something they get chronically, but they also get upper respiratory illness with it and you didn't mention that.

Get him tested specifically for leukemia, FIV and FIP. That is another one they can carry for a while.

You cannot breed a cat like this so there is no reason for him to not be neutered. He and you both will be much happier if he is.

Good luck and let me know what the test results are.