boxer mood change

Question
QUESTION: I have a large male boxer who I've had for several years along with three pomeranians(two male, one female). My two male pomeranians are fixed but the female pomeranian and male boxer are not.We recently had a very bad experience with our boxer. He attacked one of my male pomeranians and broke his jaw. He was never aggressive before this incident.We also kept our female seperated from him as much as possible. Was this just because she was in heat or could there be some other reason why his whole demeaner changed?

ANSWER: In my opinion, this occurred most definitely because your female pom was in heat.  Dogs can sense a female in heat from miles away.  And the fact that your male boxer is not neutered explains a lot of his mood change.

Your boxer sensed a female in heat, which means ready to mate, therefore his natural behavior is to want to mate with the female.  He attacked the male pom because he was competition.

Is there any specific reason your boxer and female pom are not spayed and neutered?  I can't stress the importance of spaying and neutering your pets and not adding to the pet overpopulation.

That being said you should be careful of having your dogs all together when your female is in heat as this is likely to happen again if this situation were to arise again.

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QUESTION: I kind of figured that was the reason but we have had them all for years and he has never attacked any of the dogs even during her prior heats. During this incident the female pom wasn't around the other dogs it was just them two. I also hadn't got around to fixing the other two dogs I guess because I never had a problem with the dogs and figured my boxer couldn't mate with her even if he tried. I also fear that since he now knows that he is the dominent dog that he would attack again for any reason just to let the other dogs know who's boss.

ANSWER: If you don't plan on neutering that i do suggest to monitor the situation when your female is in heat.  He can trained to resist his urges when you are there to correct his behavior.

Also, how old is your boxer, around 2 years old is when he reaches maturity and most owners notice a change in their males around this time.

I know my mothers mail boxer, even neutered started to become more assertive of his dominance around this age and we had to step up with training to let him know he is not alpha.

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QUESTION: My boxer is 6yrs old & we have never had any issues with him being aggressive he is just one big puppy.

Answer
Well while the female being in heat could have set him off, it could have also been some other factor that triggered this behavior.  If he has never done that before just be mindful of his actions and see if you can notice anything that triggers him into a different or aggressive mood.

If this was just a one time thing where something agitated him i would not worry since he has no prior show of aggression.