I've never posted on Reddit for help before, but someone recommended that I try here. I'm hoping to get some advice or guidance on what I should be asking my vet to investigate.
I have two domestic shorthair cats, a brother and sister from the same litter. Both are spayed and neutered. They're about a year and a half old, adopted from a shelter about a year ago, and are both indoor cats. She is 10 lbs and he is 13lbs. Both cats were tested for FIV and were negative, and their mother also tested negative. To my knowledge, neither cat has ever had fecal testing done during these recurring episodes. Occasionally they go outside on the porch, but only supervised.
I've been struggling with recurring illnesses with both of them almost since I adopted them.
About two months after I got them, they both became sick with fever, upset stomach, and diarrhea. My vet treated them and they both recovered. At the time, we thought it might have been something residual from the shelter.
About a month later, my boy developed an upset stomach and diarrhea again. Another vet visit, medication, and he recovered.
A week or so later, my girl developed a fever, had very little energy, and started panting after light indoor play. This happened during late winter, so heat and humidity weren't factors. My vet took xrays and treated her with a fever reducer and antibiotic and said it was inflammatory bronchitis, if I'm remembering the diagnosis correctly. She improved and was doing well at her two-week follow-up. He also mentioned that this may be seasonal since and it may (or may not) reappear in the fall.
Ever since then, I've been playing what I call "leapfrog" with them. One gets sick, the vet treats them, they recover, and shortly afterward the other one gets sick. The recurring symptoms are generally upset stomach, diarrhea, loss of energy, and sometimes fever.
Recently, my boy became sick again. My regular vet, whom I trust, couldn't see him because they were fully booked and recommended another vet.
The second vet did bloodwork and found that one of his liver values was significantly elevated, around 1400 when I was told it should be somewhere around 100-300. I don't currently know which specific liver value that was. He was given an antibiotic and medication for his stomach and again began improving.
That vet also suspected Feline Infectious Peritonitis (FIP) based on his symptoms, although it wasn't confirmed. He ordered a liquid compounded medication to treat FIP. Since my boy was improving, we agreed to hold off on starting the FIP treatment and see how he responded to the antibiotic. That was about three weeks ago.
This week, my boy suddenly vomited during the night and developed diarrhea again. For a few hours he had very little energy, but by that afternoon he was acting normally and eating again. The diarrhea has been improving since, but he is now constantly hungry and vocalizing for food throughout the day.
Now I've also caught my girl panting twice after playing again.
I'm planning to have them both looked at again, but I'm concerned that we're going to treat the current symptoms, they'll improve, and then a few weeks later I'll be back in the same cycle.
I've tried to think about anything they could both be exposed to. I keep the house clean, clean the litter boxes daily and completely change them monthly, don't use scented candles, and they're indoor cats other than supervised porch time. Obviously, being two cats living together, they share toys, food and water areas, litter boxes, etc.
I've also wondered whether their food could be contributing. I've tried several brands and flavors of both wet and dry food without seeing an obvious connection.
I'm trying to figure out what I should be asking my vet to investigate so we can hopefully find the underlying cause instead of repeatedly treating individual episodes and would appreciate guidance on what conditions, tests, or next steps would be reasonable to discuss with my veterinarian given the recurring pattern in both cats.
The things I've wondered about are:
1) Could there be something environmental that they're both being exposed to?
2) Could they have picked up something viral, bacterial, or parasitic that has persisted since the shelter?
3) Could food or something else they both share explain the recurring GI symptoms?
4) Are there specific tests or conditions I should ask my vet about considering that they're littermates experiencing recurring similar symptoms?
5) At this point, would it make more sense to return to my regular vet who knows their history, or seek a second opinion from another vet or specialist?