I have a 2 year old male cat who is not fixed. He has always been a really lovey cat who wants attention ALL THE TIME. We recently moved in February to a house in the city, and now all he does is whine outside and when he comes in the house he attacks my brother.
Is there something that I can do to help him in any way? He just acts like he does not want anything to do with the new house or any of us. Thank you!
Cats can certainly react to stress with fear, aggression, or distance, just as we can. But, the change in your cat's behavior could also indicate that he is not feeling well. While stress is most likely the culprit for the change in your cat's behavior, I would first suggest bringing your cat to a veterinarian for a thorough physical exam, especially if he has not been to a veterinarian recently. Cats that go outdoors can encounter all sorts of things, and any number of feline illnesses or injuries could be causing your cat's crying and change in personality or aggression.
Assuming, however, that your cat is fine medically, there are some important things to try. First, since your cat is not neutered, I would recommend doing so right away. Allowing an unneutered male outdoors will likely contribute to the already overwhelming pet overpopulation problem. Cats that are not spayed or neutered are also more likely to have medical issues, including cancers, later in life. But also, a male cat that is not neutered is much more likely to be aggressive.
I'm not sure how long you kept your cat indoors before allowing him outside in your new home, but he may be whining or crying because he is disoriented or unfamiliar with his new environment. If he is crying to be let back inside, and doesn't particularly seem interested in being outdoors, would it be possible to keep him inside?
In terms of the aggression your cat has toward your brother, without more information, it would be difficult for me to make recommendations. However, one of two things come to mind: Either your cat is fearful of your brother OR you are dealing with displaced feline aggression. The latter is especially likely if your cat only attacks your brother when he is let in from being outdoors. If your cat attacks your brother aggressively at various times, it could be a response to fear, and there are many things to try that could help.
I would recommend reading this question and answer from another reader regarding Displaced Feline Aggression and this question and answer regarding A Cat Who Attacks Only One Person for tips and information about things to try to help resolve the issue.
Again, feline aggression and other unusual behaviors can be signs that a cat isn't feeling well, too, so if your kitty hasn't seen a vet recently, bringing him for an exam would be wise. And, at the vet visit, you can also get more specific tips for how to help the cat behavior issues you are experiencing.
All the best,