What’s the topic for today?
Feline infectious peritonitis, known as FIP for short
Ok, and what exactly is FIP?
It’s a fatal viral disease of cats.
By fatal, do you mean there is no treatment?
Yes, that’s right. It’s fatal in 100% of cases with no treatment available
How do they catch it?
It’s a very common virus that is found in cat faeces. It spreads very easily between cats, and most cats will have picked up the virus at some stage in their life.
Now hang on a minute. If it’s always fatal and it’s common, how come there are so many cats around?
Now that’s a good question, and it’s quite a complicated answer. The virus is very common, but in most cats it doesn’t cause a problem at all. Their immune system destroys the virus. In a few cats, however, the virus mutates, and it’s this mutated virus that causes FIP.
So is FIP contagious between cats?
No, it isn’t. The harmless form of the virus is contagious, but the mutated virus isn’t. A cat with FIP cannot give FIP to another cat.
Why does this virus mutate in some cats but not others?
That is a question we simply cannot answer, as we don’t know. We do know, however, that some cats are genetically predisposed to getting FIP. We believe this is because some cats’ immune systems are incapable of destroying the mutated virus.
What are the symptoms of FIP?
The classical symptoms are typically a cat that is going downhill for no apparent reason with weight loss, lack of appetite and lethargy. Sometimes the abdomen or chest fills up with a dark yellow fluid. Basically, all the blood vessels of all the organs become inflamed, which leads to multi-organ failure.
How is FIP diagnosed?
It can be very difficult to diagnose, as there is no one specific test for it and often the symptoms are quite vague. If the chest or abdomen fills with yellow fluid, then we can do some tests on that fluid, which gives us an idea if we are dealing with FIP. If there is no fluid, then the diagnosis is more difficult.
Can’t you simply test for the virus?
It’s not that simple. We can test for the virus, but because the virus is so common, it is meaningless. There is no test for the mutated virus.
So how else can you diagnose it?
We have to collect as much information as we can and then make an educated guess. We are particularly interested in the ratio of proteins in the blood, as gamma globulin levels are usually raised in FIP. FIP is more common in young purebred cats, so we are always more suspicious of those cats.
Can you diagnose it by taking biopsies of any tissues?
We could diagnose it from a liver biopsy, but in most cases, the cat is in no fit state to go through with an anaesthetic and surgery. Sometimes we only find out for sure after doing a post-mortem examination of the liver.
So once you diagnose it, do you need to euthanise the cat?
It depends on the cat’s quality of life. Usually, they are already suffering, and so euthanasia is the best option. If they are not suffering, then because it is not contagious, we can send them home for a short while until they start to go downhill. Unfortunately, that is usually only a matter of a few days or weeks.
Is a vaccine available?
There is overseas, but it is not very effective, so it really isn’t a practical solution. Most vets don’t recommend its use. It isn’t available in NZ, so it is not an option here.
Is there any way to control it?
No easy way. It is impossible to eliminate or avoid contact with the virus, as it is so common. The best approach will be to attempt to breed cats that are resistant to the mutated virus, but that is going to be a difficult and slow process.