aggressive adult female lab

Question
QUESTION: Wanting advice on how to stop aggressive behavior.  7 yr old fixed female lab is aggressive(has bitten)to puppies and other female dogs.  She is a saint to cats, children/adults and large breed male dogs.  She has been with me 24-7 from 4 months, will obey with voice and had commands, used as therapy dog with children and teenagers.  I am totally confident with her training in any situation UNLESS there is a puppy/small breed dog. This behavior is not healthy for her, and effects her ability to be around other dogs.

ANSWER: Hi Heather,

I think at 7 years old, she is who she is. You can try creating a better association (counter conditioning), expose her to lots of small dogs safely (desensitize), you can train for incompatibility or you can manage her. It sounds like you are doing the last two effectively.

What you are dealing with most likely is a wrinkle in her brain that you cannot undo. It sounds like she has a pretty good life other than this.

---------- FOLLOW-UP ----------

QUESTION: I have heard about using a muzzle to control the biting until the animal is desensitized. Have you or others you know had positive results with this?  I do not want to scare her for the rest of her life, but I also do not want her to literally scar my friend's puppy. My vet suggested it, but has never used one herself.  Thank you for your time.

Answer
Then with all due respect to your vet, she should not be advising you about something that she has no experience with.

Muzzling will create frustration. The wrong type (soft bite miki muzzle) prevents biting but also panting. Dogs pant to cool themselves off and alleviate tension. Over heating and heat stroke can result from this approach.

Dogs aren't stupid, they can tell when they are wearing a muzzle and when they are not. When I have done civil protection work (no bite suit, muzzled dog) they bite much harder the next time.

Don't do it!!