Why are my cats fighting?

As with any change in behavior, you should always see a vet. Could be that Toby is in pain. Cats will often act out aggressively when they are hurting.

If it isn’t health related, it could be misplaced aggression. Has there been any new cats in the area? My boy cat sometimes get very stimulated by outdoor cats (he is inside only) and he will try to attack my other cats. Put Toby in another room for about 10 min. to decrease his stimulation.

Other than those explanations, I don’t know what it could be.

This page has a lengthy discussion of the different types of aggression that you may want to read. It specifies behaviors to help you identify the type of aggression.

Here is an excerpt:

“Territorial Aggression

Territorial aggression can sometimes arise suddenly between two relatively evenly-matched cats, and can take place between male-male, male-female, or female-female. Territorial aggression in the form of fighting is often accompanied by urine spraying or “marking,” which helps identify this form of aggression. The aggressor cat is not necessarily the older cat, nor the one who has been in the household the longest. He will preface his attack with much posturing: back raised, ears laid back, with accompanying growling and hissing, then leap on his victim and attempt to bite him on the back of the neck. In many cases, the “victim” cat will back down by turning and walking slowly away, and the social hierarchcy process will have begun. Other times, the victim will give tit for tat, and a violent battle may ensue.

Most housemate cats will eventually resolve their disputes; one will reign as the “alpha cat,” and the other will be satisfied with his lesser role in the “hierarchy line.” On the other hand, you may be faced with the dilemma of two cats who will never get along, and may have to be permanently separated.”

A physical exam for both of them is definitely warranted. If everything checks out ok, you may want to try a product called Feliway. It mimics a cat pheromone that reduces stress – for probably about 60% of people who try it, it doesn’t work at all. The other 40% are thrilled by the results. It’s non-invasive and easy (you can get an automatic spritzer, like a room deodorizer) and worth a try.

The attacking doesn’t sound good, but..I have a male/female pair ( fixed ) also and my male is much bigger than the female. They play well together but sometimes he tackles her too hard and she gets upset hissing and growling, but no serious fighting.

Yes, maybe check with your vet or a cat behaviorist.

Try yo put yourself in your cat’s position. Being kept in a house all the time for 5 years is bound to make anyone a bit stressed. Are your cats getting enough of your attension? Do you play with then in equil amounts as much as you did when they were younger? How long has it been since you bought them new toys? I have a male and a femal cats from the same litter (both are fixed) and it is the female that starts all the fights I think because the male gets far more attension. He is so way lovable. She gets enough attension now and is less agressive.

Could there be mice or food in the basement that Toby is defending as his?