black lab mix

Question
I have a 2yr. old black lab that was fixed about 4mo. ago after having 2 litters. After this she is still great during the day but in the evening she gets very aggressive. If she is sleeping you cannot go near her she will bite you, but all day she will play and want to be loved on. Can you help me figure out my little girl. Oh I also have a 3yr. choc. lab no problems there he is great

Answer
You may want to double check with the vet to make sure nothing is wrong with her (problem with spay or other health issue).  Also, why is anyone bothering her when she is sleeping?  That could be part of the problem there.  Part of it could also be a training issue...I would make sure the dog has had obedience training and you consistently reinforce that so that the dog knows that the people in the house are the boss.  

Having had 2 litters by age 2 is very wrong, as a lab is not mentally mature until over 2 and final health clearances can't be done until 2 years of age.  It's a good thing she is spayed now.

I would have the vet do a full work up, then if nothing is wrong, start on obedience class with a trainer who is trained for behavioral issues, not a Petsmart training class.