It sounds like the vets are suggesting prescribing the FIP meds as it is a three month (84 day) course. I have copied this verbatim from the FIP Global cats (UK and ireland) Facebook group, I'd suggest joining it, they will link you up with an admin to get excellent personal advice.
'It’s natural to worry about the cost to treat, whether you have insurance or not. Some vets are still quoting scary amounts - in the thousands - and usually it’s because they haven’t checked prices recently.
The reality is that prices have fallen a lot in the 4 years since treatment became available. Vets have a choice of two suppliers, can prescribe GS 441524 in different forms (oral suspension or pills) and prices vary wildly from vet to vet.
So, what should you expect to pay?
Well, a 3kg cat with wet FIP can be treated for around £660 in total for 84 days - if they respond super fast and meet the criteria, this could even be reduced to around £440* if they only need 42 days of treatment.
A 4.5kg cat with neurological FIP (so higher dosage) can be treated for around £1320* in total for 84 days.
The critical thing to ask your vet is for a price per bottle of oral suspension and a price per 50mg pill - we can then advise if you are being charged more than the average.
Oral suspension is always more cost effective than pills
As of July 2025:-
A 30ml bottle of Summit oral suspension is around £220
A 30ml bottle of BOVA oral suspension is around £250 - £350
A 45ml bottle of BOVA oral suspension is around £280 - £380
A 50mg pill ranges from £19 - £25.
Here at FIP Global CATS ® UK/I we have a database of vets with FIP experience and we try to maintain a list of current charges. We will do our best to help identify well priced vets in your area so that you get the best priced treatment for your cat.
If you need to fundraise, we have a platform to help with that.
We believe that EVERY cat deserves a chance to beat FIP.
*example prices based on £220 per 30ml oral suspension
Edited to add. We can also help you to discuss with your vet what tests are most useful and help you to have an open conversation about what is affordable for you. In many cases a treatment trial is a sensible way forward to keep costs down. People who have spent a lot of money in the past have often spent that on unnecessary referrals to specialists and expensive diagnostics (like MRIs) that may not have been necessary.
Overnight hospital stays will always incur expense, but for the majority of cats diagnosis and treatment can be delivered by your regular vet and your kitty can stay home with you.'