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Canine Behavior/Male dog mounting castratedmale dog


Hello,I have just read one of your post and was quite intrigued. I have a entire male that has as of yesterday, started humping one of my other castrated dogs. He got to the end point, where his penis was swollen, it would not go down and was bleeding, I had to wait some time before he went down, then I had to manually put his penis and the surrounding glands back into sheath. I contacted vet when I noticed initially he had got so aroused that he finished, however they said it is ok, the dog has continually tried to mount the castrated dog, so now I have to separate them, what can I do
P.s olive in Melbourne australia

Thank you for your question. I apologize for the delay in responding.

Intact males will mount other individuals (male and female) for many reasons, none of which are actually sexual in nature. In dogs, the penis becomes erect when the dog contracts muscles around a bone that push the penis forward. This muscle may contract when the dog is excited, nervous, angry or sexually aroused, and so simply seeing 'pink' isn't necessarily an indication of sexual arousal. Many dogs (male and female) will go through the motions of mounting and thrusting as part of social rituals, inept play behavior, attempts to solicit attention, attempts to control an overly stimulating environment, to establish role/dynamic with that other dog, etc. The act of mounting and thrusting can bring on the erection simply as an instinctive reaction to the physical motion (sort of like mouth watering at the smell of tasty food, it's just a reaction with no thought behind it).

Sometimes dogs who become erect during that process will actually complete the act to ejaculation. Once a male has ejaculated, the penis and surrounding glands swell. During normal mating, this swelling is referred to as the "tie" because it ties the male and female together. That tie usually lasts from a few minutes to half an hour before the swelling goes down and the dogs can separate. Nature does this with dogs because they are promiscuous and tying is nature's way of the male making sure the female doesn't go and mate with another guy before his sperm have gotten a fighting chance at "landing."

So, the fact that your male dog became erect and ejaculated and then became swollen for a period of time is not something to be concerned about. In actual fact, you probably didn't need to physically assist as the swelling would have continued to diminish and would have returned to a normal state on its own. So long as the dog didn't appear to be in pain, I wouldn't be terribly concerned about that.

But, I am concerned that you saw it bleeding. Was it really blood? Was it just a reddish discharge that could have been semen? If it was actual bleeding, I would bring that information to the vet again for discussion.

Let me be clear - I am NOT a vet. I have NO formal medical or veterinary training. I cannot diagnose any medical condition. I can only share my thoughts and what I might do if this were one of my boys...

To the best of my knowledge, it is NOT normal for a dog to bleed from his penis after ejaculation. I would be concerned about an infection or a growth that was irritated by the action of ejaculating. I would probably ask my vet to do a thorough examination of my dog's penis and run a urinalysis to check for a bladder or urinary tract infection (UTI). I may request blood work to see if the white cell count was elevated (indicating infection) so that if no UTI is found, we would know if we need to look elsewhere in that area for infection.

So while there are many reasons why the mounting took place, and it's not totally uncommon for the dog to complete the act even if it was not part of a proper mating, the bleeding is of concern to me.

As to why your dog may have aimed his affection at your neutered male, and in the several days since, continues to do so, my best guess is that there's a female in heat in your neighborhood. If you male can't access the female, but he's filled with hormones, he may direct it at the nearest object available, in this case your other dog. I've known of dogs who will direct that attention at plush toys or pillows - also completing the act - because it was the nearest thing to him. Another possible trigger would be a health condition in the intact dog that is triggering an increase in hormone production (this would likely be a pituitary issue).

You didn't share if these dogs just met or are new to living together. If they are just getting to know each other, it may be triggering a social behavior and they are determining who will make the rules between them - though mounting and thrusting to the point of ejaculation in that circumstance is a lot less common and so I'd still find it to be a bit concerning.

For the time being I would not allow them to have unsupervised time together. When they are together and you're supervising them, I'd be watching for any signs that the intact male is about to mount the neutered male. I would interrupt that behavior before it starts, or as soon as it starts if possible and redirect their attention to another activity - a favorite game, some tasty treats, a brief training session, a nice marrow bone or stuffed Kong to chew on (in separate areas to avoid conflict over ownership of such high value items).

If it is just a female in heat, then in a couple weeks your intact males' behavior should subside and life will return to normal. You may also find your male trying to escape your property to go hunt for that female, so be cautious about his outside time, or leaving doors open, etc.

I hope this proves helpful. Please feel free to followup if I can be of any further assistance.

Jody, APDT
Los Angeles Behaviorist

Canine Behavior

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Jody Epstein, MS, CPDT-KA


IF YOU BELIEVE YOUR DOG IS ILL OR INJURED, PLEASE CONTACT YOUR LOCAL VETERINARIAN IMMEDIATELY. THIS IS NOT THE FORUM TO ADDRESS URGENT MEDICAL ISSUES. I AM NOT A LICENSED VET AND HAVE NO DIAGNOSTIC SKILLS. ***I have been answering questions on All Experts for over 8 years now. I enjoy being able to offer assistance in this forum. I do need to be clear, though. If you’re looking for free advice about a specific behavior question, you MUST submit your question to me via All Experts. If you bypass All Experts and write to me directly through my website, I will ask you to submit via All Experts. On the flip side, if you’re local to Los Angeles and you wish to speak to me privately about an in person consultation, please go through my website. I appreciate your assistance in keeping my volunteer work on the volunteer site.*** I can answer questions about the following canine behavior issues: obedience, timid/fearful & fear-based aggression, nuisance behaviors, families that are expanding with either new human or new animal members and many other issues. If you have potty training questions please first read my trio of blogs at If you still have questions after reading the blogs you can post your specific questions here. PLEASE be as specific as possible when asking a question. Give me a detailed example of the situation - dog's behavior, body language, circumstances surrounding the issue, what the consequences are (another dog's response, your response), etc. I can only provide insight if I can get a picture of the whole scenario. If I ask for further details, please provide them. In person I would normally observe for at least 90 minutes to assess the situation and the dynamics before offering tools and suggestions to modify it. In writing it is ever so much more difficult. Thank you for your participation in the process.


I have been a professional obedience trainer for 9 years, and specializing in behavior modification for 8 years. I have owned dogs my entire life. I own my own dog training and behavior modification business called Nutz About Mutz.

I am a Certified Profession Dog Trainer - Knowledge Assessed (CPDT-KA), #2133301 ; I am a member in good standing with the Association of Professional Dog Trainers (APDT), #77763 ; I am an AKC certified Canine Good Citizen evaluator (CGC), #71253

Publications ; ; Multiple articles in the local pet magazine Pet Press (found across Southern California)

I have a masters degree (MS) in Animals and Public Policy, with a minor in Animal Behavior, from Tufts Cummings School of Veterinary Medicine. I also have 3 years of graduate education in Animal Behavior and Learning from UM-Missoula and UL-Lafayette. I continue to educate myself to canine-specific behavior through extensive reading, online interactive workshops, vidoes and attending canine behavior conferences, workshops and seminars. Beginning in March, 2017, I will be the Behavior & Training Manager at Second Chance Center for Animals in Flagstaff, AZ.

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