How Long After Cats Are Neutered Are the Hormones Gone?

The advantages of neutering don't necessarily appear overnight.
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Neutering a male cat often brings upon a lot of positive benefits, from eliminating icky urine-marking behaviors to even drastically minimizing issues with aggression -- phew. Once your precious pet is fixed, however, it may take a little while for the hormones to exit his body completely.


If you're experiencing a little bit of behavioral difficulty with your little one, you may feel a little impatient. However, the North Shore Animal League indicates that it usually takes a maximum of between six and eight weeks for all of the hormones to fade out. Don't get antsy if your cat still continues on behaving in his usual hormonal way. Allow his body a little bit of time to adjust and adapt to the surgery.


Remember that your male cat also may remain fertile for a little bit of time post-surgery. Because of this, be cautious for a while and keep your fluffball away from all unfixed female cats. After all, he may still be able to get them pregnant -- no thank you. The East Bay SPCA indicates that, surprisingly, tomcats may remain completely fertile for a maximum of six weeks after the procedure.


Neutering surgery entails the removal of a tomcat's testicles, which are home to the male hormone testosterone. These hormones are the driving force behind male reproductive traits. Once the hormones are completely gone, a male cat is simply no longer driven by his hormones, and understandably so.


After approximately six weeks or so, you may notice that your male cat's hormonally influenced behaviors have either been totally eliminated or at least greatly reduced, much to your joy. Some of these pesky behaviors include restlessness, urine spraying, aggression, excessive vocalization and constant attempts to roam and run away. Although rather rare, some male cats may retain these behaviors out of habit, especially if they were fixed at a comparatively older age -- perhaps over 1 year in age.

Early Neutering

The North Shore Animal League indicates that it may be preferable to neuter tomcats before they hit the 5-month mark in age. If you fix a cat at an early "kitten" age, it may minimize the chances of him having already developed and taken on hormonally charged behavioral patterns, whether urine marking or fierce and aggressive fighting with neighborhood felines.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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