Possibly FIP

Hi from Melbourne, Australia. My cat Ollie (Domestic Short Hair, approx. 11 months, neutered, around 3kgs) is a foster fail who came to us 6 months ago with cat flu (treated & recovered well) but apart from that he has been all good!

On the 9th of December at night, he didn’t come for his dinner like he normally did and I thought not much of it as we had wormed him just before.

On the 10th as I was leaving in the morning, I noticed that he hadn’t eaten his food and had no desire for food, and was a bit lethargic. He was also wheezing. I came back around 2pm and noticed that he hadn’t eaten (we have cameras), hadn’t gone to the toilet, was still sleeping, he wasn’t coming for food, barely drank water, his lethargy increased, he was breathing rapidly and still wheezing, and he seemed quite weak. As soon as I noticed this I decided to take him to the emergency vet as he wasn’t himself. However, when I went to pick him up he was lying in his own urine and it stunk and was orange.

We got to the vet and she told us we could either keep him overnight or take him home with us but come back 1-2 days later and assume it’s cat flu. I decided to take him home with us and we left with some doxycycline which I administered shortly before I went to bed.

Today, the 11th, I syringe fed him water as the vet advised and gave him his dose of doxycycline. He seemed the same as yesterday and still wasn’t eating or drinking. I left to get a bunch of cat broth and food for him and came back 2 hours later. I syringe fed him water but noticed that he was quite weak and stumbling everywhere. He was breathing very loudly and rapidly again with the wheeze but it seemed to be worse. I then decided to rush him down to the vet.

Now he is on oxygen and they have found fluid in his lungs. The vet is very adamant that it’s probably FIP or pyothorax.

I would like to know what other people think? Thank you.