Adopting an FIP Survivor: 84 Days, 3 Rechecks, 6 Months

An FIP survivor is adoptable, but the file decides more than the cat's mood on the day you meet. Three numbers separate a real case from a story: 84 days of antiviral treatment, 3 rechecks after the last dose, and 6 months of observation before anyone says cured. Ask for those three and you can judge a file in 10 minutes.

84 days is a course, not a suggestion

The accepted antiviral course for feline infectious peritonitis runs 12 weeks, which is 84 days, and most cats look well long before it ends. Appetite often returns between day 10 and day 21, and abdominal fluid may be gone by week 4 or 5. That improvement is the trap: owners stop at day 45 or day 60 because the cat is eating again, and the file then documents a partial course. A properly handled case shows a dated first dose, a dated last dose, and 84 days between them.

Run two arithmetic checks. Twelve weeks is 84 days, so a course that ran 40 days was not a course. And the weight should appear twice, at day 0 and day 84, because a cat that gained 0.8 kg over 84 days is a different patient from one that lost 0.3 kg. Ask for the day 0 albumin and globulin too: a starting albumin:globulin ratio under 0.4 with a globulin over 5.0 g/dL describes a cat that was genuinely sick.

Why the clock reads 6 months

Relapse clusters in the first 90 days after the last dose, which is why nobody responsible calls a cat cured on day 84. The common protocol is 6 months of monitoring, meaning 180 days past the last dose, or day 264 counted from the first tablet. Some clinics extend to 12 months for cats that had the neurological or eye form, since those carry the highest relapse rate.

That is not a reason to refuse the cat. It is a reason to price the next 180 days into the decision: 3 vet visits, 3 blood panels, 1 or 2 abdominal ultrasounds, and a weight log you keep at home. A kitchen scale that reads to 10 g costs less than 1 panel and catches drifting weight 2 to 3 weeks before most owners notice a thinner cat.

Three rechecks, and the numbers inside them

The 3 rechecks are not 3 identical visits. They are spaced to catch different failure modes, and each has a number you can read off the report without a vet translating it.

Checkpoint	Day of protocol	A:G ratio floor	Weight vs. day 0
Baseline before dose 1	0	recorded, often 0.3 to 0.6	100%
Mid-course panel	42	0.6 or higher	100% or more
End of course	84	0.8 or higher	100% or more
Recheck 1, 30 days after	114	0.8 or higher	within 2%
Recheck 2, 90 days after	174	0.8 or higher	within 3%
Close-out, 180 days after	264	0.8 or higher	stable for 30 days

Recheck 1 is the globulin check. Recheck 2 is the ultrasound, looking for fluid that has come back in the abdomen or around the kidney. The close-out visit is the one that lets you insure the cat without arguing about a pre-existing condition, so book it before month 8.

Two risk classes you are underwriting

Medical risk is the obvious one. The signals that end a good streak are a temperature at or above 39.5 Celsius (103.1 Fahrenheit), weight loss of 5% or more in 14 days, a rising globulin with a falling albumin, fluid re-accumulating within 8 weeks of the last dose, and any new wobble, head tilt or pupil change. Any 1 of those 5 means a vet visit within 24 hours.

Financial risk is the one adopters underestimate. Most insurers treat FIP as a pre-existing condition, so anything related to it is excluded for the life of the policy, and a relapse at day 200 bills like a new case. Hold 1,500 to 3,000 USD aside for the first 12 months; the cost calculator shows the first-year total faster than a spreadsheet at midnight.

What a complete file contains

Five documents. The treatment log with the first and last dose dates and the drug name. Lab values at day 0, day 42 and day 84: albumin, globulin, A:G ratio, hematocrit, total protein. The imaging report, not a phone photo of a screen. A weight curve with at least 6 points. And a discharge summary signed by the treating vet that names the form of the disease, effusive, non-effusive, neurological or ocular. If the foster home kept a daily appetite note, read it: a cat that ate well on 78 of 84 days is a better bet than one with 3 unexplained fever spikes, and no panel shows that pattern.

Cost of the 264 days, not just the 84

Treatment is the largest line and varies by country, weight and drug source; in the United States, 84 days commonly lands between 2,500 and 6,000 USD. After the course, expect 120 to 250 USD per blood panel, 150 to 350 USD per ultrasound and 60 to 90 USD per recheck exam, so 3 rechecks plus 1 scan adds 500 to 900 USD. A relapse caught at day 120 costs a second course, which is why funding the monitoring is part of adopting rather than an optional extra.

Red flags in the first 90 days

Call the clinic the same day for labored breathing over 40 breaths a minute at rest, refusal of food for 24 hours, a temperature over 39.5 Celsius, yellow gums or ears, or a belly visibly larger than it was 7 days ago. Call within the hour for open-mouth breathing, collapse or a seizure.

Before you sign

Ask for the 5 documents and read the dates, not the summary line.
Confirm the form of FIP: effusive, neurological or ocular.
Book recheck 1 for day 114 before the cat comes home.
Set aside 1,500 to 3,000 USD for the first 12 months.
Start a 10 g weight log on day 1, same hour each week, before feeding.

If the shelter cannot produce the dates, ask whether the cat was treated or merely suspected, and read the screening guide before you decide. A survivor with a documented 84-day course and a 6-month follow-up is one of the better bets in a shelter; a cat labelled cured with no numbers is a question mark with fur.

Terms mentioned in this article

FIP

Frequently asked

Is an FIP survivor contagious to my other cats?

The virus that causes FIP is a mutated form of feline coronavirus, and that mutated virus is not shed in any meaningful way by a recovered cat. Most vets treat a survivor as no more risk than any other cat, though routine separation for the first 7 to 10 days is sensible while you watch for stress-related illness.

What if the shelter only has a 40-day treatment record?

Treat a 40-day record as an incomplete course and ask the treating clinic for the original dates, drug name and day 0 lab values. If nobody can produce them, the cat is a suspected rather than confirmed case, and you should budget for a baseline panel, an ultrasound and 6 months of monitoring before committing.

Can I insure a cat that finished FIP treatment?

You can buy a policy, but nearly every insurer excludes FIP and anything it links to as a pre-existing condition, and some add a 12-month waiting period for immune-related claims. Get the close-out visit and its lab values on paper first, then ask the insurer in writing how they will treat a relapse at day 200.