Cant reconize eachother? (kitten, male, smells, house)

[koterman99]

Hello, I have 2 male cats, One is 7, And the other one is 8 months old. They were BEST friends till today, My 7 year old cat ran away last night for 12 hours, but I found him around 12 PM and I brought him back in the house and my 8 month old started hissing and growling at him then he started to attack him. (My 7 year old does not have front claws but my 8 month old does.) I tried to get them to bond but they just hissed and growled at eachother. Is there a reason for this?

[Happy in Wyoming]

They do this because of different odors they pick up while they're away. I had this experience when a cat was away in the hospital for several days. When he returned home the other one hissed. The one who had been away tried to show affection but he received only strong rejection. That episode lasted several hours but it could be longer depending upon the individual cats.

[Rene S]

This is a classic case of misdirected aggression. Your older cat has different smells that your younger cat doesn't recognize or like. This happens at our house every time a cat goes to the vet.

Separate them for overnight or a day, and slowly re-introduce them. You can also rub a towel on the younger one, then rub the same towel on the older one to help them smell the "same." Whatever you do, don't force them together. Let them work it out slowly.

[goyguy]

"Ditto" to all of the above - what an impressive response time!!!
When my now 15-month-old "cat-olescent" Seteria came back from the vet last July after spaying and an overnight stay, her own mother gave her nothing but grief for almost three days. It seems so strange when cats have eyes and should be able (with their relatively limited visual capabilities relative to ours) to "know" another cat right away. But it is what it is!
Whatever you do, please don't de-claw the kitten.