My Male Shih Tzus are Fighting?

Brief：
I have 2 four year old male shih tzu brothers that we have had since they were babies. One of them is neutered and the other one that is not. The neut.. 

I have 2 four year old male shih tzu brothers that we have had since they were babies. One of them is neutered and the other one that is not. The neutered one is calm, but the one that is not is picking a fight with the other one. He would growl at the other one when he passes by then he would get closer and start fighting. This has never happened until recently, but I am afraid that when we are not home, they will start fighting and hurt or even kill each other. What should I do?

i had the same problem until i neutered all of them.end of problem!they never fought again! You'll have to crate them separately while you're gone until the aggressive male gets over it. Check with your vet, he/she may have a better solution. I think when u are not home put the one that is agrasive in another room and close the door. Do this untill they stop fighting when u r home. When u are home whatch them and if they start growling than spank the one lightly. What u could also do is get someone else to help u by putting them on a leach and walk them around ur house so when they pass each other if they growl say no in a stern voise and lightly spank him. u could also give treats to the one that stays calm, if the one that growls stops growling than give him a treat he might realize it was wrong. So good luck. Cya! Why isn't the second one neutered? Neutering not only helps with hormonal issues with dominance and such, it also decreases the risks of cancer.

You should separate them when you are not there to supervise. Either crate them or put them in separate rooms.

Also, most dogs don't reach maturity until 2-4 years old, so this could be his "adult" personality coming out. You may want to rule out any medical problems and then consult with a behaviorist.