I am sorry to hear your cat is sick. My name is Rebecca. I am a veterinarian, and will do my best to help.
How old is Bean? You wrote 42, but I assume that is not her age!
Do you mean FIP, or FIV?
Sorry that is my age oops! she is 7 in April
Then it would be very unlikely for her to have FIP. That is usually seen in young cats and kittens. Possible, but I have never seen it in a cat older than 2. Most are under 1 year of age.
Which is good, because FIP is a fatal, incurable disease.
Any ideas of what it could be?
Has she been tested for FIV and Feline leukemia?
She had a booster 10 days ago
Booster for what?
Feline panleucopenia, feline clamydiosis, feline herpesvirus/calicvirus (dead vaccine), Feline leukaemia virus
But has she been tested for Feline Leukemia, or FIV?
If she is infected with the feline leukemia virus already, the vaccination would not help.
Here in the US, we do not give the feline leukemia vaccine to cats older than two, and do not give the panleukopenia, chlamydia, herpes/calici vaccine to cats older than 7.
So if she has not been tested for feline AIDS (FIV) and feline leukemia, that would be the first thing I would do.
Not yet the vets have sent the blood off to check for FIP she was ill last year after the booster and i think she was checked when and the results came back negative.
I would also consider testing for Toxoplasmosis.
FIP has no reliable test, but would be very rare in a cat this old.
But FIV does have a reliable test.
And could cause these symptoms.
what is Toxoplasmosis
Toxoplasmosis is a parasite, that sometimes migrates to places like the eyes and brain.
Is there a treatment for it?
Not common, but something I would test for. But I would test for FIV first ( Not FIP; two different diseases).
There is a treatment for Toxoplasomosis, yes. Clindamycin.
I don't know whether she's been tested for that. are the symptoms the same then?
The symptoms for all of these are fever, not eating, dehydration, sometimes anemia, seizures, blindness. The symptoms can vary from cat to cat.
I would first do a test for feline leukemia and FIV. Those are the more common diseases. If that is negative, I would send out a test for Toxoplasomosis.
I would also be doing tests of her red and white blood cells counts, and "chemistries" to check for liver or kidney disease.
Her white blood cells count was very low they are checking for liver problems
The low white count, with a fever and blindness, is all the more reason to test for leukemia and FIV, to me.
What treatment can be taken if I get the vets to test foe them and it comes back positive?
If the tests for either of these viruses is positive, the prognosis is not good. There are therapies, like feline interferon, that may help for awhile, but these, like FIP, are fatal diseases. I have seen cats live for years with them, but they do eventually die of these diseases.
But if they are negative, you know you have ruled them out, and move on to testing for things like Toxo.
I will have a chat with the vet about the Toxoplasmosis, can you think of any other illness it could be apart the ones we've spoken about?
It would help if I could see her blood tests: liver and kidney values, red and white cell counts, etc.
FIP has to be on the list, but I have never seen it in a cat this old.
Another thing that has to be on the list is lymphoma, a form of cancer.
But viral diseases, and Toxoplasmosis would be the first things I would rule out.
Since she is showing signs of neurologic disease (blindness, unsteady on her back legs), a spinal tap and analysis of the fluid would be a helpful test. But that may require a specialist.
But start with the feline leukemia and FIV tests. These are simple tests, can often be done in-house, and are accurate. There is no accurate test for FIP, unfortunately.
I am not seeing responses from you, and the website says you have gone offline. Is there anything else I can answer, or help with?
Sorry just trying to get her to feed and drink some water. Thanks for your help I will talk to the vet about all this.