older and younger cat getting along

Question
We have a 4 year old neutered male cat that we introduced a female 8 wk old kitten to about 3-4 mo ago. (He grew up with a neutered dominant older male cat in the house - but then he died. They had gotten along famously.) We slowly introduced the 4 yr old cat and the kitten, and afterwards they were great friends. They played and groomed each other. Once in a while, starting about 3 weeks ago, our male cat started hissing and swatting at the kitten when she came by him, but they still occ played together. Then the hissing and swatting started to increase - yet they till played sometimes, but less often. Two days ago, I brought the kitten home from the vets after getting her spade.  Now it doesn't appear like the kitten is even trying to play - just wanting to walk from one room into the other, as she tries to get by him and our male cat just spits, swats and hisses at her. Is there anything we can do? What might be going on?  

Answer
Hi Karin,

It's nothing to worry about yet. What is happening is normal cat behavior. Social play with kittens lasts about 4-6 months. It then tapers off but not to the point were they don't play together.
When you brought your kitten home from the vet she had all sorts of strange animal smells on her. This is making the male think that a new cat is muscling in on his territory. Take something with your scent on it and rub it over the kitten. This should help here.
The kitten just had major surgery; let her recoup from it. She will be better in a couple weeks. Good luck and write back to me if things don't settle down between them.

Ciao, Karen