After treatment: follow-up and relapse

Most treated cats go on to live normal lives. Your vet will usually want follow-up checks for a few months after the last dose.

Normal after successful treatment

• Some lymph nodes may stay slightly enlarged, and lymphocyte counts can be a little high.
• Cats that had nerve signs may keep a mild wobble. This can be lasting damage rather than active disease.

Relapse

Relapse is possible, usually within the first few months. In one molnupiravir study about 1 in 8 cats relapsed between 9 and 99 days after stopping, and a second course brought those cats back into remission. Relapses with nerve signs have also been described after short courses. Watch for returning fever, appetite loss, a swollen belly, breathing changes, wobbliness or eye changes, and contact your vet promptly.

Later care

• Vaccination and neutering have been done during or after successful treatment without relapse. Your vet may time them carefully.
• One study found a slightly higher rate of a type of lymphoma (about 2%) within two years after treatment. It's not clear whether this is linked to FIP or the treatment, so it's worth keeping up regular check-ups.

When your vet ends treatment, mark the plan complete in FIP Together. Your records stay available for follow-up visits.