We have a couple of two year old male neutered cats, Ed and George, who have lived with us since they were kittens. Until yesterday, they were on exceptionally good terms, and would play, groom, and sleep together, and generally do things as a pair.

They are house cats, but we do give them a couple of hours of supervised time in the garden each day. It was during one of these outdoor sessions yesterday that the problems started: Ed suddenly became aggressive, and decided to chase George into the house out of our sight. From this point on, George has barely appeared from under the bed, and whenever Ed approaches, he hisses and growls. On the other hand, shortly after the initial attack, Ed returned to his normal self, and appears to be unfazed by George. He keeps attempting to make contact with his brother under the bed, but is constantly rejected.

To assign human emotions to them, it looks like George is now scared, and Ed is confused about his brother's behaviour. However, I know that this might not be a true reading of their 'thought processes'.

This situation has now been ongoing for around 24 hours.

A theory we have as to why Ed initially became aggressive is that it was a case of mistaken identity: there are other cats on the street, and we wonder if he detected the smell or sound of another cat nearby, but then mistook his brother for a rival. We think this has happened once before, but without lasting consequences. However, it is a guess on this occasion as we never saw any other cats during the incident.

Why would two otherwise loving cats suddenly turn on each other? Is it possible that George is now too scared of Ed to be around him? Or is it more likely that Ed is trying to obtain a dominant position? And how can we return back to the status quo in this sort of situation?


1 Answer 1


I don't think it's really possible to guess why exactly this happened. Occasionally something like this happens because of some change. For instance, it's relatively common for cats to suddenly not get along if one of them undergoes a medical procedure such as a surgery. The cat that underwent the procedure most likely has a weird smell which alarms the other cat. Sometimes sudden aggression could be a medical issue also, but I don't think that is the case here as the aggressor has resumed its normal behavior.

As for what to do about it, I would try separating the two cats for a little while, and then once they seem calmer, a gradual re-introduction, along similar lines as if you were introducing new cats. Start by feeding them close together, but with a door separating them. Then have short supervised meetings. Gradually increase the time of the supervised meetings, and then let them be together unsupervised when you are satisfied the cats are comfortable with each other again. I think since they were fine up until now, it is likely that they will be able to coexist in peace again after they are given time to calm down.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.