Can feline distemper (panleukopenia) heal on its own?

Feline distemper generally does not heal on its own. If you see symptoms, take the cat to a vet promptly; timely treatment lowers the death rate. Signs include persistent high fever, stubborn vomiting, acute diarrhea, no appetite, and sharply dropped white cells.

Note it is highly contagious – isolate other cats and watch them; at the first sign take them to a vet too. Safest is to have all cats checked, or test at home with a distemper antibody strip.