I think he is resource guarding his bone but they may feel a bit left out now that baby is home. I haven't had a kid yet, but from what I have heard from other dog owners is that it is pretty difficult managing both baby and dogs at first, but once you get into a pattern and into the hang of the things it gets much easier. Just hang in there!This is my first time owning a dog. My wife and I complicated the situation by taking in a young stray only 6 months after getting our first dog. We went to lots of classes and got help from many friends on training them and they are well behaved in the sense that they respond quickly to my commands, I can walk them without a leash and make them come with 100% recall, and they respect the rules we set for them.
One of the dogs is a large dog, he's half great pyrenees, half lab. We had him since he was very young. The other dog is smaller about 50 lbs and she is also well behaved except that she is jealous (always trying to get pet when you are petting the other dog) and she takes the larger dogs food from time to time. This has made the larger dog, who before this has always been very very passive to become defensive when it comes to his treats.
Today I was with the smaller dog and approaching the larger dog while he was eating his bone. He looked defensive so I put the smaller dog in the garage and approached him at which point he growled at me. I think I made a mistake then because i slowly walked away went inside grabbed a treat and used it to approach him. Should I have tried to reprimand him for growling at me? I have to admit I love my dog but even though I met him when he was 5 lbs, seeing a 100 lb dog growl at you menacingly is still scary.
Never, ever punish a dog for growling. That is their way of warning you, and if you punish them for warning you they will skip the growl and go straight for the bite. A growl is something to listen to, because it is telling you to back off. You did the right thing by going to get a treat. He is "resource guarding" his bone because it is high value. You can help this by giving him a treat every time you walk by him when he is chewing. He will learn he doesn't have to protect his bone. Also, if you have to take the bone away, "trade up". Offer him a treat, and when he goes for the treat, take away the bone. You can practice doing this too.
In any case I would like to know how others feel the proper way of dealing with a situation where a large dog is growling at you. He has never been aggressive except for this one time he growled at me. He has never bit anyone and has been in one short fight with a pitbull who has gotten into a fight with every dog on my block.
Oh one thing I forgot to mention which is probably the most important factor. We just had our first baby 10 days ago so there is a chance the dogs are feeling neglected (they get a walk a day now instead of 2 and less play time with me).