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Neutered male cat 6 weeks ago: Why is he still aggressive and humping?

Updated on September 23rd, 2025

Pet's info: Cat | Russian Blue | Male | neutered | 10 months and 20 days old | 9.25 lbs

Got my male cat nutered 6 weeks ago and he's still very aggressive towards my 4 year old female cat. Also still has the urge to hump.

4 Answers

Most Helpful Answer

Answered By David Darvishian

Veterinarian

Published on July 31st, 2017

Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sounds like Prince is still experiencing some signs associated with the male hormone testosterone. The testosterone levels drop after the neuter and should be decreasing now. Hopefully this behavior will ease up as the remaining testosterone gets out of his system. If things don't resolve or his signs worsen, I would advise that your veterinarian take a look at both of them to assess any problems. I hope this gets better soon.

1Pet Parents found this answer helpful

Related Answers from Veterinarians

Answered By Cara, DVM, cVMA
Veterinarian
It may take some time for the effects of testosterone to leave Princes system, and some of the behavior may just be kitten play as he is still pretty young. I would have your female cat spayed as well if she isn't already just to reduce the stimulation for him.
1Pet Parents found this answer helpful
Answered By Megan, DVM, CVA
Veterinarian
Unfortunately sometimes the humping doesn't go away. If Prince is really dominant the aggression and humping could be a sign of dominance. Also, Russian blues can sometimes have an aggressive personality. You may want to consider adding some feliway diffusers and sprays in your house to help calm him. Also, try to increase the environmental enrichment. Also be sure there are plenty of places for each of them to have their own personal space and be sure you have at least 2-3 litter boxes so no one is guarding and getting territorial over one litter box. Finally, if this doesn't help, he may need to be placed on a low dose of anti-anxiety medicine to help him adjust. Unfortunately, not all cats get along but most will get to the point where they tolerate one another. I hope this helps!
0Pet Parents found this answer helpful
Answered By David Darvishian
Veterinarian
Published on December 9th, 2017
Hi and thanks for using Petco Pet Education Center, formerly Petcoach! Sorry to hear about your cats. Not sure how old Batman is but it could take up to 2 months for the testosterone level to decrease after neutering if he is an adult cat. These 2 cats may never get along and you may have to resort to using some medication(s) to address this problem. You could try some pheromone sprays (Feliway) or calming sprays and see if that doesn't help. There are also some diffusers that you plug in that can potentially calm down some pets. If this behavior continues and it's significant I would advise taking them to your veterinarian for a consultation. Your vet may advise some medical tests to rule out a medical problem but this sounds like primarily a behavioral problem. One or both cats may need to be put on some medication to address any fear/anxiety/stress that they are experiencing. Good luck with your kitties.
1Pet Parents found this answer helpful

Smart Picks for Smart Questions

Related Questions

My kitten was just neutered. Why is he still humping my other cat?

Once all the male hormones have left the younger one's body, this should stop. It sometimes takes a few weeks (3+) for all the male hormones to go. Now that the younger one has no more testicles, there will not be any significant testosterone production anymore. Your older fellow is a sweetie and obviously not too worried and might see it just as play. As long as they do not have serious fights, I would not worry about it.

Updated on September 23rd, 2025

Training & Behavior

My neutered cat still humps and pees outside the litter box. Why?

Well, it can take about 60 days for the hormones to leave his system after neutering, so some may still be hormonal. However, cat’s will often have inappropriate urination if they are stressed about other things or if they are painful or otherwise upset. If the marking doesn’t improve in the next month then I would highly encourage you to have him evaluated by your veterinarian soon to discuss options. Best of luck and I hope he improves soon. Thank you for using Pet Coach.

Updated on September 23rd, 2025

Why is my neutered cat suddenly aggressive towards his twin?

It can take several weeks for testosterone levels to decrease after neutering. Until then, consider using a pheromone product, such as Feliway spray or plug in diffuser, to decrease any anxiety or aggression in the home. Provide extra litter boxes, bowls, toys and bedding to prevent food aggression or resource protection.

Updated on September 23rd, 2025

Why is my neutered cat spraying and humping? Is he really neutered?

Male cats that are neutered after they reach sexual maturity are more likely to continue to exhibit behaviors that were caused by testosterone even after they are neutered. These behaviors can include urine marking and humping types of behaviors. That is one of the reasons that we recommend neutering before sexual maturity. If the shelter neutered him before you adopted him, then I would not doubt that he is neutered, but you certainly can have your veterinarian examine him just to be on the safe side. Cats that have testosterone in their system will have physical characteristics that your veterinarian will be able to determine on exam. Good luck! I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

Updated on September 23rd, 2025

Training & Behavior

Why is my male cat aggressive, hissing, biting, and fighting? Is neutering the answer?

Hi and thank you for your post on Petco Pet Education Center, formerly Petcoach! These can be common behaviors in male cats that are not neutered. I would recommend neutering him soon to help decrease these behaviors a bit. In addition, neutering him will help lessen the risks of cancers later in life as well as help decrease the feral cat population.

Updated on September 23rd, 2025

Food & Nutrition

Why is my male cat aggressive and hungry after neutering?

You should have him checked, or rechecked, by your veterinarian. Neutering typically does not result in more aggressive behavior. Additionally, any sudden behavioral change can be due to illness or injury. Once medical causes have been ruled out, you can focus on behavioral issues. Consider a pheromone product, such as Feliway Spray or plug in diffusers, to help decrease anxiety or aggression. Provide additional litterboxes, bowls, toys and bedding to prevent resource protection. You may have to separate them for a week or two then gradually reintroduce them while employing the measures described above.

Updated on September 23rd, 2025

Training & Behavior

Why is my cat still aggressive after neutering? Feliway isn't helping.

It takes 4-6weeks after neutering before the hormones and related behavior subsides. Be aware however that not all bad behavior is hormonal and some cats will never be friends and many need to be segregated. Calming diets and supplements such as kalm aid can help alongside the feliway

Updated on September 23rd, 2025

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