I have a 2 year old cat. My husband and I bought a new kitten for both ourselves and we thought that my 2 year old cat would enjoy having him around to play with when we are not home. At first, Macie, the oldest, did not like the kitten! After a couple of days they began to explore each other and within a week they seemed like best friends. They played, chased each other, slept together, everything! I left for college and now Macie seems to want to kill the kitten. She hisses, growls and even attacks the kitten. I am afraid for both of them but want to keep them. What was strange is that the first time it happened, the next day Macie was his best friend again. But it has happened again just a week later and I don't know what to do. Can you help?

Hi sometimes the weather can put cats in a strange mood raining mainly, It could be the kitten as picked up some scent off another cat, But I think your older cat is letting the kitten know who is boss and to keep away when it does not want to be bothered, Don't worry about them the kitten will survive without much damage.
CHRIS.

Macie is probably stressed that you are going away. She's taking her feelings of stress and transferring them to the kitten in the form of aggression.

I suggest you get a Feliway Comfort Zone plug in. Feliway is a natural phermone produced by cats facial glands. It helps them feel more relaxed and less stressed. I am using them in my home and it works wonders.

Also, leave something with your scent on it like a shirt or something you have worn recently. Put it where Macie likes to sleep.

Regards,