Whilst there is no proven evidence about the effects of treatments such as flea and worming, vets are generally very cautious about prescribing any medication including flea and worming as the concern is it may or may not stimulate their immune system. This could cause the FIP to reactivate causing it to come out of remission.
It is also well known that FIP cats and kittens should never be vaccinated again.
Fleas can be checked for by using a flea comb and if you suspect fleas FIP cats and kittens can wear a Serestro flea collar.
Worms can be checked for by asking your vet to do a faeces check no more than every six months and if worms are present a wormer can then be used however not a multi function product just a straight wormer.
Antibiotics should also be avoided unless necessary and then ask your vet to consult with a treating vet as what is the best option.
Try and avoid anaesthetics as well unless absolutely necessary. There are other ways to deal with desexing such as Superlorin implants which are done by injection.
Try and avoid as many treatments as possible for your FIP cat and kitten.
Remember diet is everything to help them build their immune systems. A high protein diet or kitten diet will help. You can talk to your vet and be guided by them or contact one of our mentors for guidance.