Why is my neutered male dog mounting a spayed female puppy?

Yes, I recommend to have her spayed between 5-6 months of age. It's hard to know exactly why he suddenly started doing that, It's possible she is coming into heat. It's also possible the mounting was not sexual in nature: https://www.petcoach.co/article/mounting-behavior/ I hope this helps.

Hello. He is just being a male dog. Even after neutering, some males may still try to mount females, but in his case, he is still strongly attracted to your spayed female. If you do not plan on neutering the male, keep an eye on the male as the female can get annoyed at him & you may have a fight on your hands. If your male is still quite young, he may mature out of this behavior as his instincts are very strong right now. Just keep an eye on him. Thanks for contacting Petco Pet Education Center, formerly Petcoach.

This is not a sexual behavior, but likely a response to stress, anxiety or to assert his dominance. Correct the behavior immediately when you see it. Remove him from the dog with a stern "No" and offer a toy or task to distract him. Praise and reward him when he complies. If he persists, separate him until he settles down. Be firm and be consistent.

Humping is not only a sexual behavior, it can also be a dominance behavior, a stress response, etc. Any new changes lately - new pet in the home, any major changes in his routine or in the house? I suggest you refer to this article for more information. Hope this helps. ( https://www.aspca.org/pet-care/dog-care/common-dog-behavior-issues/mounting-and-masturbation )

Hello and thank you for reaching out to Petco Pet Education Center, formerly Petcoach. No, it is not concerning that he is mounting other dogs. This is a dominance behavior, more than a sexual behavior. Neutering does not make these types of behaviors go away - even some female dogs will mount other dogs! Rico is likely just playing and trying to assert his dominance and be "alpha" to the other dogs. As long as he acts playful to the other dogs and is not being aggressive/biting/fighting, this mounting is just fine! I hope this is helpful - best of luck with Rico!

This is generally more of behavioral issue but spaying Pixie may also help to decrease the behavior. Here is a link about mounting: https://www.petcoach.co/article/mounting-behavior/ I hope this helps and best of luck.

No, there is nothing wrong with the surgery. Dogs hump for other reasons like dominance behavior, play behavior or excitement. I suggest you refer to this article linked below: ( https://www.aspca.org/pet-care/dog-care/common-dog-behavior-issues/mounting-and-masturbation )