My cat has very bad mouth odour and is producing thick saliva, It has been diagnosed as FIV?

Hello & sorry about your cat, beings it has no cure , is fatal, if it were me, I would have the cat put down so it don't have to suffer & no more cats now for awhile ..this virus will live in the soil, etc, wherever the cat has been for long periods of time..there are vaccinations for it, but no kitten can be vaccinated, if you find or can adopt a cat already vaccinated for FIV, then things should be OK..sorry, but I am one who is greatful they will & can put sick, suffering, dieing animals down..even tho you love them..sometimes you have to love things enough to let them go as well...Take Care :)