How to check if a cat is a ‘week cat’ (doomed kitten)?

When buying, watch the cat’s spirit and appetite; normal reaction, activity and appetite mean it is healthy and unlikely a ‘week cat’. Check eyes, nose and anus for discharge; clear eyes and clean nose or anus mean health.

Also note breathing – heavy breathing suggests disease, possibly a week cat. Finally, a vet virus test: if it has panleukopenia it often dies within about a week, marking it as a week cat.