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Why is my intact male dog suddenly marking and dominating his brother?

Updated On September 23rd, 2025

Pet's info: Dog | Miniature Pinscher | Male | unneutered | 6 months and 10 days old | 8 lbs

I have two 6 month litter mates males. One is a runt (Radio) & the other it pretty large for his age (Mega). Both are still in tact. Last night Mega raised his leg on the wall like he's marking. A few minutes ago he raised his leg on Radio. Nothing came out, but I immediately seperated them. Mega's behavior has been strange. He'll literally stand over Radio, pushes him with his body, basically walk all over him. I stop it and put Mega in time out but it's not working. What is going on with him?

1 Answer

Most Helpful Answer

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Answered By Mirissa Duncil, DVM

Veterinarian

Published on July 15th, 2017

Well the key here is both of your pups are intact. This sounds like Mega is exerting dominance over your other pup with his new found hormones. I would recommend neutering both if you do not plan to breed.

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