Cat of the March :) Puzzle

There was a cat. The hostess adored him, but cat behaved terrible.
Just March is outside at the yard - no cat. Only at the end of May - all ragged, thin, but happy cat returns.
At least the hostess got sick, she took him to the vet. The vet something, somewhere clipped, sewed, and said - now you have not a cat, but "just kitty."
Again came March, and the cat disappeared. April, May, summer - there is no cat.Fall - no cat, just with the first snow cat back fat, fluffy, and again, very pleased and happy. The hostess could not stand:
- Listen, Bob! We're with you were a doctor, and he something to you had clipped ...
- Oh! With my talents and experience, I was worked as consultant! :)