Why is my 10-year-old cat suddenly aggressive and attacking me?

Sorry you are having some troubles with Monster! I recommend that you take him to your vet for a senior blood panel. They can check his thyroid as well. Hyperthyroidism (an overactive thyroid gland) is not uncommon in older cats and can lead to behavioral changes, more vocalization, eating more, acting odd. Get him in for bloodwork when you can! Thanks for asking Petco Pet Education Center, formerly Petcoach!

Aggression in cats can sometimes be due to an underlying medical cause such as hyperthyroidism that can be treated by your veterinarian. Unusual aggression can also result from increased stress from a change in routine e.g. a move, a new animal or baby in the house etc. If this is the case, your veterinarian can prescribe anti-anxiety medications to get Maria through this stressful time.

That is very unusual and sounds scary! There could be a few reasons for this behavior. Sometimes there could be pain or a medical condition causing a change in behavior. Since Oscar can't talk and tell you what is happening, I recommend to have him examined by the veterinarian to be safe. Sometimes this behavior is related to the stress of seeing another cat outside. For some cats, this causes frustration and they can then exhibit bullying type behavior to other pets or people within the house. If the veterinarian thinks this is behavioral, there are a few things you can do. Try enriching the environment. Here is a great article about cat's instinctual needs: https://www.petcoach.co/article/why-every-cat-needs-a-place-to-climb/ Use a Feliway diffuser, set aside 30 minutes a day for vigorous play (really get him moving) and/or switch the food to Royal Canin Calm. If he is the only cat in the household, you may try feeding him out of a food puzzle. Hide food for him to find. Do not use these last two mentioned options if you have other cats. Provide a stand or resting place by a window so he can look outside. You may also try clicker training him for positive behavior. Here is a link about training cats: https://www.petcoach.co/article/can-i-train-my-cat/ Wash all windows and doorway exteriors where a cat may be spraying outside. Try to drive out the cat if possible. You may also need to block the window where you think Oscar may be viewing the cat most frequently. Most cats response best to combination therapy. The veterinarian can also prescribe medications which can help with aggression/stress. I hope this helps and please feel free to post any additional questions.

A sudden change in behavior may have, at its root, injury or infection. Ideally, Rostom should be physically examined by your veterinarian to diagnose and treat any medical causes for his sudden aggression. Neutering him should be strongly considered as testosterone can be a driving force behind aggressive behaviors. Once medical causes have been ruled out, you can address behavioral concerns such as stress or anxiety. A pheromone product, such as Feliway Spray or plug in diffusers, may help decrease any aggression or anxiety. A gradual desensitization to loud noises can also be done to lessen Rostom's response to them.

If this is a recent change in behavior I'd recommend having your veterinarian perform a thorough physical examination as a first step. Some common diseases in older cats like hyperthyroidism can make them much grumpier than usual. Pain from arthritis can also make cats react in an aggressive way. If your veterinarian feels there is no medical reason for the behavior change I would then recommend talking to a feline behavior specialist to see if there are changes you can make at home to address this behavior. Cat bites are no joke - veterinarians have lost fingers due to infected cat bites and cellulitis! But it sounds like there could be some other things to look into before deciding on euthanasia.

A sudden behavioral change in cats that previously got along with no other changes to the environment can sometimes indicate issues such as underlying pain or illness. Bringing the cats in for an exam is a good first step to rule out any health issues that could be causing the aggression. If they check out healthy, adding in some pheromone diffusers can help with inter-cat stress. Making sure each cat has their own access to food, water, litter, places to hide, etc can also help decrease tensions.

Hello, Sudden changes in behavior can be secondary to an overactive thyroid or disease in the brain. I would advise you to have Digit examined by a veterinarian and discuss diagnostics such as bloodwork including thyroid levels, chest x-rays and abdominal ultrasound.