I have an 8 y/o neutered dog. I recently adopted a female, spayed 8 m/o dog. I had no idea a neutered dog would still mate!

She is much smaller and he is constantly trying to mate with her.

Can anything be done to stop this behavior? I do not have the space to keep them separated outdoors and only have a bathroom or bedroom to keep one of them while the other is outside.

Please help!

He needs to be checked by a vet to make sure the neutering was complete or is still in effect.

(Did you adopted him from a shelter? We had adopt a supposedly neutered cat from a shelter, but the cat turned out to be still intact.)

If he's neutered, he's not mating. But rather trying to show that he is the alpha dog.

I've seen neutered dogs still try and get it on... It's not abnormal. Your boy just really thinks he's a man

She needs to tell him no. All the correction from you in the world will not stop it.

If he is endlessly trying and no sign of stopping... Than you may be a single dog family.

It is most likely a dominance thing. Neutering does not reverse.