My 4-month-old cat is aggressive. Is locking her up making it worse?

Sudden aggression and behavioral changes in cats can indicate pain or illness, so if you haven't already, a veterinary check up is best. If your cat checks out healthy, it may be there is a lot of stress causing your cat's behavioral issues. Making sure she has her own access to food, water, toys, treats, hiding spots etc from other pets or people is best. She is also still very young, and may just have a lot of energy/is still learning what appropriate behavior is. Ignoring bad behavior, increasing play and activity times, and rewarding calm, quiet behavior is best to teach her the right way to interact and to get out that excess energy. If the behavior continues even with this, speaking with a veterinary behaviorist is the best next step.

Unfortunately, kittens that were bottle fed can be aggressive and not as friendly. You can try to put some feliway diffusers in the House and spray her sleeping areas. Feliway is a cat pheromone which can sometimes help to calm them. Also, give her more time. She has been moved from multiple house in her short life and now around new cats (they don’t usually remember family). This can be stressful and can take weeks for them to acclimate to. I hope this helps and she starts to get use to her new living conditions.

Aggression is usually associated with negative behaviors such as hissing, growling, swatting, etc. What you are describing sounds more like normal kitten playfulness, if Bella is just pouncing, nipping, or hopping around. Keeping her out of your room if she is too excitable can help keep her form hopping on you when you are trying to sleep. A pheromone diffuser such as Comfort Zone can also help her to relax and settle down some. Making sure she has plenty of toys to play with, including things you can safely play with together such as a feather on a stick or a laser pointer can help get out some of that energy without having her bite you or scratch your hands. If she becomes too excited, getting up and walking away/ignoring her until she has calmed down again can help teach her that the fun ends when she gets too excited. If she is calm and quiet, rewarding her with a treat, a play session or some attention can help teach her that's the behavior you like. If she is actually showing aggression, IE biting hard, hissing, ears pinned, low growling, swatting, etc, then I would highly recommend seeking out a trainer or behaviorist in person to address the issue and try to find the cause such as stress or fear.

I am sorry to hear about Lucy! Many cats can have personality changes at around 2 years of age as they truly reach maturity. That compounded with the fact that she is unspayed and has had a changing life situation over the past few months could definitely be affecting her personality. I would recommend an exam by a vet and having her spayed. I would recommend a feline pheromone diffuser in the house called Feliway, and a calming supplement such as Composure or Zylkene https://m.petco.com/shop/en/petcostore/product/vetri-science-composure-feline-bite-sized-chews# as well. If her aggression continues then a veterinary behaviorist consultation would be recommended.

It sounds as though Sam has a behavioral problem with aggression. If you have not tried the Feliway products yet, I would recommend doing so. These are pheremone products that are supposed to help calm cats down. I would make sure that she has plenty of environmental enrichment (toys, scratch posts, etc.). If these do not help, I would recommend discussing anti-anxiety medications with your veterinarian. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

You can consider re-homing him if that is what you would like to do. Your other option is to take him to the vet and speak to them about getting him some behavioral modification medication that he can take daily which will hopefully calm him. You should also try some Feliway diffusers and some environmental enrichment for him. ( https://www.feliway.com/us/Products/FELIWAY-CLASSIC-Diffuser ) ( thedrakecenter.com/materials/environmental-enrichment-indoor-cats ) ( https://www.youtube.com/watch?v=AejmrLa_Cs4 )

Unfortunately the new cat is likely causing stress and this is a common feeling reaction to stress. She may not want to go outside as long as that other cat is around. It may be difficult to keep the other cat out of your area unless you want to purchase or build a fence. There are fences available that have curvature to the top that make it difficult for a cat to climb over. There are some things you can do at home that can help to manage her stress. Set aside 30 minutes a day for a vigorous play. Use a pheromone diffuser. There is a special prescription food made by Royal Canin called calm which may help. Use food puzzles. Give environmental enrichment. Lastly, your veterinarian has medications which can help as well. Many cats require a combination of therapies. Best of luck.