2 years old cat suddenly angry and spitting

[emcee]

Hello,

i am a bit in a despair about our 2 years old male cat, Fantastic.

We adopted him a year ago, he was homeless on the country side. He tested fiv+ but still we kept him, and had him vaccinated and sterilized.

He never went along so well with our 11 years old cat, but they could share the space. We now have a 4 months old kitten and he played with her a lot until this week.

Suddenly, he bitted our 11years old cat, and does not play with the kitten anymore, instead, he is spitting at her and even at me. He eats well, run around, but seems only to be interested in eating, sleeping and fighting with all cats around. And marking is territory in and out the house.

Since he is fiv+, i think he is a danger for the surrounding cats, including ours.. And i really wonder who would like to adopt such a cat... so we are left with the euthanasia option, or to leave him on his own in the forest, as he was when we found him (although it would not be the forest where we found him).

Any advice will be welcomed, my heart is broken at the idea of having to put him to sleep... i am so against this 'solution' but don't know what else to do...

emcee