Possible FIP in kitten

Hi everyone,

I rescued 3 kittens and momma about a month ago from my backyard. I'm working on getting them adopted but I'm concerned about one of the kittens. When I first found them, they were all very playful and energetic but about a week ago, the one just seemed to lose interest. Took him to the vet, no fever, she thinks it could be a parasite. I will be getting those results today.

He's still eating, but he has diarrhea. Very lethargic and thin. He got his first vaccine and Revolution about two weeks ago. He is approximately 2-3 months old. Any advice would be much appreciated. Thanks!

for the kitten. It could be something like giardia or coccidia, both of which are far more common than FIP.

Thank you! I really hope so. Vet just called with the results of the fecal, no sign of parasites. She said she is going to treat for a bacterial infection. Hoping this brings him back to normal