When treatment doesn't work

Most cats treated for FIP do come through. The evidence is genuinely good, with roughly eight to nine in ten cats responding to treatment (Gokalsing et al., 2025; Taylor et al., 2023). I tell you that not as a measure you should have met, and never as a reproach, but because it's the truth and you deserve the truth: this treatment usually works, which is exactly why it can feel so bewildering and so unfair when it doesn't.

But some cats don't respond, and that is about the disease, not about you. A small number of cats are simply too unwell by the time treatment can start, and some deteriorate in the first weeks despite everything being done correctly (ISFM, 2024). FIP is a serious illness that until very recently took almost every cat it touched. That your cat's body couldn't win this particular fight is not a failure of your love or your effort. It's the hard edge of a disease that doesn't always yield, even to good medicine and a devoted owner.

If part of what you're carrying is guilt, that you didn't notice soon enough, didn't have more money, didn't do something differently, please try to set it down. Those thoughts are grief looking for somewhere to land. They are not the truth of what happened.

The truth is that FIP can hide and can move fast, that diagnosis is genuinely hard, and that even cats who start treatment early and get everything right can still be among the small number who don't respond. Hindsight lays out a tidy path that was never visible at the time. You made your decisions in real conditions, in fear, with love, on the information you had. That is all any of us can do, for a cat or for a person, and it is enough. There was no secret door you failed to open.

Some of you are reading this not at the end, but in a frightening middle, where things are slow or wobbling and you don't yet know which way it will go. If that's you, please don't read "doesn't work" as your answer, because slow is not the same as failing.

Recovery from FIP is often gradual, and a cat who isn't bouncing back on schedule may still be getting there. When a cat's response is genuinely stalling, there are things a vet can still weigh: reviewing the dose, sometimes increasing it or splitting it through the day, extending the course, or looking harder at whether a harder-to-reach form, like the neurological or ocular type, needs a different approach (ISFM, 2024). These are decisions for your vet to make with you, and it's worth having that frank conversation before concluding that nothing more can be done. If you're not sure whether your cat is stalling or truly failing, that uncertainty is itself a reason to talk to your vet today rather than sit with it alone. And if what you're really trying to understand is what a good outcome would even look like from here, what remission really means may help you frame the conversation.

I've kept this part brief on purpose, because if you're in the fighting phase, this isn't the article you need most. But I didn't want a single owner with options left to feel those options had already closed.

There may come a point, and your vet will help you see it clearly, when continuing to treat the disease is no longer the kindest thing, and keeping your cat comfortable becomes the goal instead. This is one of the hardest turns a loving owner ever has to make, and I want to be very plain about something: choosing comfort over more treatment is not giving up. It is a different kind of love, the kind that puts your cat's experience of their days above the fight itself.

The question that matters here is not "have we tried everything" but "how is my cat, right now, in the life they're actually living". A cat who has stopped eating, who is in pain that can't be settled, who no longer seeks out the things they loved, is a cat telling you something, gently, in the only way they can. Vets often talk about looking for more bad days than good ones, and about the small things that made your particular cat themselves, the sunny spot, the greeting at the door, the lap at night. When those are gone and can't be brought back, letting go becomes an act of mercy rather than defeat.

If it would help to have a steadier way to see it, rather than trying to judge through tears, your vet can walk a quality-of-life assessment through with you: a simple, gentle look at appetite, comfort, mobility, and whether the good moments still outnumber the hard ones. Many owners find it a relief to have something to lean on other than their own second-guessing, and it can turn an impossible feeling into a clearer, kinder picture. Your vet will not rush you through it, and there are no wrong answers in it.

There is no prize for waiting longer, and there is no shame in deciding it's time. Equally, there is no shame in wanting a little more time to say goodbye properly, as long as your cat is comfortable. You know your cat better than anyone. Trust that.

If you reach the decision to let your cat go, I want to spare you having to search for this at the worst possible moment, so here it is, calmly.

Euthanasia is a gentle process, designed above all to be peaceful and free of pain. Your vet will usually give a sedative first, so that your cat drifts into a deep, comfortable sleep in your arms or on their favourite blanket, unafraid and unhurting. The final injection that follows is painless and works quickly and quietly. Most cats simply slip away as if falling asleep. You can choose to be there or not, and neither choice is wrong. You can ask for it to happen at home rather than at the clinic if that feels gentler, and many vets will arrange this. You can take whatever time you need, before and after. Your vet and their team have walked beside many families through this, and they will guide every step so that you don't have to hold the details, only your cat.

Whatever you choose about afterwards, a burial, a cremation, ashes returned or not, there is no right answer, only the one that feels right to you. If you're not ready to decide in the moment, it's perfectly all right to ask your vet to hold your cat while you take a day to think. Nobody will hurry you.

If there are children in the house, or other pets, you may be wondering how to help them too. Children usually cope best with gentle honesty in words they can hold, and other cats or dogs sometimes seem to search for their companion for a little while. Both are normal, and there's warm, practical guidance for both further on, whenever you feel able to look for it.

Grief for a cat is real grief, and after FIP it often comes tangled up with exhaustion, with the strange emptiness where the medicine routine used to be, and sometimes with a guilt that has no business being there. Please be as gentle with yourself as you were with your cat. You are allowed to be undone by this. The size of the grief is only the size of the love.

That emptiness where the routine used to be catches many people out. For weeks or months your days were shaped around doses, weigh-ins and checks, and now there's a quiet where all of that stood. It can feel disorientating, even purposeless, and it can make the loss hit in waves at the exact times you used to care for your cat. If that happens to you, it's not a sign you're grieving wrongly. It's just love that still has somewhere it wants to go and nowhere to put itself for a while. That eases, gently, with time.

And if you're carrying the particular weight of having chosen the moment, please know that owners who make that decision are, in my experience, almost always the ones who loved most carefully. You didn't fail your cat by letting them go. You spared them, which is the last and hardest gift you had left to give.

When you're ready, and only then, there is somewhere to bring it. Our Rainbow Bridge space holds a community of people who understand this particular loss, and a place to remember your cat. Our end-of-life care and loss guides are there too, with gentle, practical support for grieving, for helping children or other pets in the house, and for finding your feet again. There's no timetable. Go there when it helps, not because anyone is telling you to.

For now, there's nothing you need to do. You loved a cat through a hard illness and you stayed with them to the end. That was the whole job, and you did it. Whatever comes next can wait until you're ready for it.

And if, one day, it comes back to you at an odd moment that your cat lived a short life or a hard-fought one, try to let this sit alongside the grief: they were never once, in all of it, unloved or alone. Cats don't count the years. They know warmth, safety, a familiar voice, and being cared for right to the last. You gave your cat all of that. It was a life well loved, and that is the thing that lasts.