Intact male behaviour issue with older spayed female
I have a 14 month old intact male GSD who lives with a much older spayed female. He gets quite a lot of exercise every day, and I'm starting to work with him on some more formal training. I won't try to pretend he's an angel, but he is friendly, regularly socialises and plays with other dogs without any issues, and generally listens well and is eager to please me and learn.
...that is, until it comes time to let him outside at home.
At the moment, his main goal in life at home is getting out in the garden with the female so he can run his face through her urine, preferably while she's doing it. When I stand up, he rushes to the door, licking his lips and chattering. The instant he thinks they'll be going out, I have a raving lunatic on my hands. All training goes out the window and he is completely unable to concentrate on anything other than getting out to the female.
This has quickly become an issue that creates a lot of stress. It's difficult to get the two of them out the door without him potentially hurting her. He's so obsessed that he very briefly gets somewhat aggressive with her. If I let him out first, he will either turn around and jump on her or else charge her down from across the garden. If I put her out without him, I have to physically restrain him while she goes in and out. It sounds like I'm murdering him: wailing, barking, crying, foaming at the mouth, and so on. He is 85 pounds, and I wouldn't be able to hold him if I weren't a big guy. Once the two of them are actually outside, he's perfectly fine.
I'm not really sure what to do about this. I've tried distracting him when he's outside so I can let her out, but it isn't much help. The obvious solution is that he doesn't get to go out with her, but this is a huge physical challenge. He is somewhat dominant of the female in other aspects of home life like when they meet me when I get home, and what's worked well for that is making him lie down and stay for a time out until he calms down. That option is completely useless here because he is so single minded about getting out to her that his attention span drops to almost nothing, he ignores treats, he doesn't listen to corrections, and so on. Lately I've tried crating him while she goes outside, but I'm afraid he might hurt himself. I've considered leaving him in there for longer periods so he doesn't know when she's actually going out, but it doesn't solve the issue of him constantly being on alert waiting to get out with her.
I asked for some help with this elsewhere and most people simply couldn't get past the fact he isn't neutered. I realise this is a sexual behaviour, and I have no attachment to his testicles whatsoever, but I'm not at all confident it would magically solve anything. I'm quite worried anything I try without getting advice from more knowledgeable dog owners is just reinforcing his bad behaviour and might cause other issues. I would greatly appreciate some help or comments of any kind.