My cat's FCoV test: positive antibody, negative antigen. Is she sick?

Cats infected with a feline coronavirus generally do not show any symptoms during the initial viral infection, and an immune response occurs with the development of antiviral antibodies. In a small percent of infected cats (5 to 10 percent), either by a mutation of the virus or by an aberration of the immune response, the infection progresses into clinical FIP. Cats can become persistently infected and continuously or intermittently shed virus with the feces. One of the most difficult aspects of FIP is that there is no simple diagnostic test. The ELISA, IFA, and virus-neutralization tests detect the presence of coronavirus antibodies in a cat, but these tests cannot differentiate between the various strains of feline coronavirus. A positive result means only that the cat has had a prior exposure to coronavirus, but not necessarily one that causes FIP.

Hi, thanks for using Petco Pet Education Center, formerly Petcoach! FIP is hard to diagnose. It is usually a diagnosis of exclusion, meaning all other diseases have been ruled out. The most accurate test is PCR of belly or chest fluid when the cat has the wet or effusive form of FIP. There is also the Dry or granulomatous form which likes the brain and eye. A simple blood test is riddled with false negatives and positives. Simple put a cat positive for coronavirus doesn't mean it has the mutated viral form that causes FIP. Unfortunately Mia's eye problem could be from FIP, but also many other things and sadly there is no 100% way to tell you that. FIP is not curable, it is a terrible disease. If Mia is doing well then I'd take that. And see if anything happens in the future. I hope this helps and I wish Mia the best!

I'm sorry to hear that! FIP is a nasty disease in cats, so I definitely understand your worry. I will try to answer your questions and give you some basic information about how this disease works - it's a bit more complicated than most other infectious diseases! FIP is caused by a coronavirus - coronaviruses themselves are extremely common in cats, and almost all kittens are exposed to them at some point. In a very few cats, the virus mutates into a much more dangerous form and causes FIP - this seems to be partly related to genetics, but it's not fully understood why this happens in some cats but not others. So although the coronavirus can be passed from cat to cat, FIP is not really considered to be a contagious disease because most cats who are exposed to a coronavirus will never develop the more dangerous, mutated form that leads to FIP. So, the bottom line is that your kitten will probably be just fine. There isn't much you can do at this point, since there is no diagnostic test for FIP. Although a vaccine does exist, it isn't recommended by the AAFP (American Association of Feline Practitioners) because it hasn't been shown to be effective and can actually cause illness in some cases. I would recommend preventing your kitten from having any further contact with your friend's cat to be on the safe side, and monitoring your kitty for any signs of a problem - but it's very likely that she will be just fine :)

It can take around 3-4 weeks for a titer test to become positive after exposure to feline coronavirus (FCoV). However, the vast majority of cats have been exposed to coronavirus at some point in life and a positive titer does not provide any useful information regarding the treatment, prognosis, or clinical signs potentially associated with this virus. Only 5-10% of cats may convert a coronavirus infection to feline infectious peritonitis (FIP), but there is no way of knowing which cats may make this viral seroconversion. I hope this helps to clear up any confusion!

Coronavirus is present pretty much anywhere and most cats would be positive for it (even asymptomatic ones). Being positive does not mean that coronavorus is the cause of the signs. These could be compatible with an upper respiratory tract inflammation/infection or possibly to a rhinitis (inflammatory, allergic, infective). A clinical examination at your local veterinarian is essential to confirm these clinical suspicions and treat appropriately. Antibiotics may be needed. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!

Hi and thank you for your question on Petco Pet Education Center, formerly Petcoach! The blood results are in German so it is hard to interpret. There are two types of the feline corona virus: the enteric version and the mutated enteric version which causes FIP. A FIP diagnosis requires a blood test, clinical signs/symptoms and a history. If fluid is present in the abdomen, testing that fluids for the virus will indicate FIP. Just becomes Hadid has antibodies against the corona virus, does not mean he has FIP. All is means is he has been exposed to the virus and developed antibodies. Blood results together with Hadid's history will help determine diagnosis. It is great news Hadid is eating and has no fever. This is a good sign Hadid is heading the right direction. I hope this has helped!

I'm so sorry to hear about Theo's battle with FIP. That is, by far, one of the most heartbreaking diseases to diagnose in this field. Most cats are exposed to the coronavirus that causes it, but only an unlucky few convert the virus to FIP. As far as we know, this is based on a genetic predisposition and has nothing to do with exposure from the environment or other cats. If Meika is having loose stool, I would recommend having her seen by a vet. It is much more likely to be due to a common problem, such as a minor parasitic infection or stress colitis from grieving her playmate. They will likely recommend a bland diet, probiotics, or a short course of anti-diarrheal antibiotics if her only symptom is mild loose stool. I cannot say that FIP is impossible, but it would be very low on my list of concerns. I hope this is helpful and gives you some peace of mind. Thanks for using Petco Pet Education Center, formerly Petcoach!