Why is my female cat suddenly aggressive towards my male cat?
Updated On September 23rd, 2025
My 7 yr. Old indoor female cat is suddenly becoming aggressive and wanting to fight and growl at my MALE 5 yr. Old indoor cat. They both are up to date with their shots! She almost acts as if she doesn't know him.
2 Answers
Most Helpful Answer
Published on July 2nd, 2017
Something is probably going on with her, she is possibly ill or in pain and that may be causing her to be aggressive. i would recommend taking her to the vet for a checkup and blood test to make sure she is in good health first.
1Pet Parents found this answer helpful
Related Answers from Veterinarians
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Published on July 4th, 2018
Cats can have very strange behavior while in heat. This is probably why the male cats are acting strange around her. My best recommendation is to have your cat spayed as soon as possible. This will eliminate any further issues. In the meantime you can keep the female away from the males to avoid any dangerous interactions. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck.
1Pet Parents found this answer helpful
Health & Wellbeing
Hi there! I have three cats that I’ve lived in the home together for a minimum of three years. All of a sudden within the last few weeks the two male cats have shown random aggression in fear towards each other. They get into growling/yelling match
That is concerning! As with any sudden change in behavior, it's a good idea to schedule a veterinary checkup for all of yours cats. In some cases, aging related issues such as pain or arthritis may cause a cat to become more aggressive in an attempt to protect itself, or it may start getting picked on by other cats in the household. In the meantime, making sure all three cats have easy access to food, water, litter, places to hide and rest, etc can help create zones where they can relax without starting a fight over these resources. Adding in a pheromone diffuser such as Feliway to shared spaces (such as eating or sleeping areas) can also help reduce inter-cat aggression.
Updated on September 24th, 2025
Training & Behavior
We have three cats in a 2 bedroom apartment. We have had the 2 of the cats for 3 years and the other one for 2 years. One of the older cats, who has always been docile and nice has recently turned very mean to our younger cat. She has not let her out
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.
Updated on September 24th, 2025
Food & Nutrition
Hi. I have 3 cats. One I introduced 2 years after getting the first 2. The 3rd has become very withdrawn and acting aggressively, one of my older ones chases her and seemingly plays but she reacts very aggressively with hissing and retires to a hidde
Sudden aggression and behavior changes in cats can sometimes indicate pain or underlying illness. I would make sure to schedule a vet checkup to rule out any health issues that could be causing the behavior. If she checks out healthy, making sure all of the cats have their own access to food, water, litter, bedding, places to hide, etc can help decrease inter-cat tension. Spending some time with each, and giving your cat a break if she becomes too irritated or agitated may help as well. If the behavior persists or worsens, speaking with a trainer or behaviorist in person is a good next step as well.
Updated on September 24th, 2025
Health & Wellbeing
One of my Male cats has started to bully one of my female cats.they have grown up together since they were both small and have never had any problems at all until about a month ago. I'm confused because there hasn't been any changes in their enviorme
Have him examined by your veterinarian to diagnose illness or injury. Either are common culprits of a sudden behavioral change. Being an intact male may also be playing a role in the behavior. Consider having him neutered. In the meantime, provide additional food/water bowls, beds, toys and litterboxes to prevent food aggression or resource protection. Consider a pheromone product, such as Feliway Spray or plug in diffusers, to decrease any anxiety or aggression in the home.
Updated on September 24th, 2025
Health & Wellbeing
My cat has gotten very violent lately for no reason, what could be the problem?
Any sudden change in behavior warrants an exam with your veterinarian. Frequently, illness or injury can be the cause. It may also be some redirected aggression, especially if Bella can see or hear cats outside. If she is upset by them and can't get to them, she may strike out at whoever is close. Once medical causes are ruled out, check your property for signs of nearby ferals or neighborhood cats. Use a pest repellant along the border of your property. You can buy a liquid or powder at most hardware or home improvement stores. Try to limit her sight from windows or doors if possible. Try a pheromone product such as Feliway spray or diffuser to decrease any anxiety or aggression.
Updated on September 24th, 2025
Health & Wellbeing
My 2 years old female cat who i've had since she was 7 weeks old has become aggressive towards other people in the house and visitors for no reason. My cat has attacked my sister till the point that she had about 4 holes in her arm where my cat had
I'm so sorry to hear that Kitty seems to have a change in her behavior. I would be concerned that she may not be feeling well or potentially be in pain, causing her to be aggressive. I would recommend you take her to your veterinarian to have a full physical exam. There may be something physically wrong with her causing her to act out. If she is not spayed, I would also consider spaying her, as hormones can cause behavioral problems. If she is healthy and there is no underlying medical cause of her change in behavior, there may be something in her environment that is causing her stress. Sometimes environmental enrichment, like shelves, cat towers, etc, can help with behavior issues. Feline pheromones (Feliway) can also help some stressed cats and calm them. Finally, some cats do need to be put on behavior modification drugs, if the other previously discussed things are not the problem. You can discuss this with your veterinarian. Best of luck! I hope she is acting more frien
Updated on September 24th, 2025
Health & Wellbeing
For about a week my cat is all of a sudden being a bit aggressive, shes growling, hiding, hissing and hitting my kitten who shes used to love and get along with. This happened after she finished being in heat and doesn't seem to be getting better, sh
Aggression can often be a response to pain. I recommend getting her checked by your vet as soon as possible, especially since she just finished a heat cycle. She could have an infection that is making her uncomfortable and in turn making her lash out against the kitten. You vet may run some labwork, do a physical exam, and based on these results, will be better able to tell you what is going on with your cat and how to treat her from there.
Updated on September 24th, 2025
Health & Wellbeing
Why have my cats (who are sisters) suddenly turned on each other and viscously started attacking the other one?
It may be due to illness or injury. It can also be redirected (or displaced) aggression. This is when one cat is unable to directly respond to a perceived threat and "vents" on whoever is closest. This is usually an owner or another pet. Never handle or grab your cat if she is displaying aggressive tendencies. This can lead to a serious bite or scratch.
Schedule an exam with your vet to rule out medical causes. If they are indoor cats, provide a ' cool down' period by separating them. Keep stray or strange cats away from windows or doors and out of your yard. Control what your cat sees by closing doors or drawing the blinds. Consider using pheromone products to decrease anxiety/stress level in the house. Search www.pet360.com for pheromone products.
Updated on September 24th, 2025
Health & Wellbeing
My friends cats have begun fighting after getting along for quite some time. She knows that means someone I'd sick but which one and with what possibly?
Those are tough questions to answer without being there to visualize each cat. But I would say generally speaking whichever cat is acting abnormal. Abnormal behavior can mean anything from the cat being lethargic (lacking energy), vocalizing more, drinking more water, or even going to the litter box more frequently. As far as what illness could be causing this, there isn't enough information as of yet as to what symptoms either cat is displaying besides be increased aggression. Do some monitoring of both cats over the next few days to gather clues and then feel free to repost your question with specifics so that we can discuss some possible causes. However, in general we do worry about kidney and urinary infections in cats. Also a change in mood could indicate an endocrine disorder, brain malfunction or even diabetes. I hope this helps and look forward to more information about your fur babies. I do hope we can figure things out soon and get them to being friends again.
Updated on September 24th, 2025
Health & Wellbeing
You I have a cat that is roughly 10 yrs old he is a Male few months ago we got another older female cat both are fixed..recently our Male cat has been attacking our female I mean really attacking her...I am worried that there maybe could be something
A sudden change in behavior from the normal, including suddenly being aggressive, can be a sign of a medical illness. I would recommend having him seen by a vet in the morning for a health check. By the way, I love the picture of them in their beds in front of the fire. So cute!
Updated on September 24th, 2025
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