black lab attitude problems

Question
We have a black lab who is about 3 years old. We have gotten another puppy, and he (Captain) was completely fine with this. In the past week or so, Captain has begun to growl and show his teeth at me and my husband when we correct him for for trying to hump our little puppy, or for simply chewing on furniture. He is fixed, so I do not understand where all the anger is coming from. Do you know of anything we can do? If not, I'm afraid he will have to be put down, I do not want his anger to be directed towards our son.

Answer
Usually changes in behavior stem from health issues or changes in the home.  You might want to do a health check just to make sure nothing is wrong.  But you and your husband might be behaving different now that the puppy is in the house, and Captain has decided that you 2 are not acting like you are in charge, so he is taking over.  

Usually when you bring a puppy in, you acclimate the puppy to the schedule already set up in the house for the adult dog.  Him humping the pup is telling the pup HE is in charge.  Dogs get it, people don't.  

This also might be a good time to re-enroll in an obedience class to remind Captain about what is expected of him.  You take the adult, your husband take the pup and everyone gets a nice refresher on general good manners for the household.  

About chewing the furniture, he is just showing you that the house belongs to him and it might be a good time to make sure he has plenty of toys to chew on and if he can't be trusted in the home, there is nothing wrong with taking a few steps back and crate him up when no one is around to supervise.