Black Labs

I agree it does not seem totally normal, however I have a 3 year old female lab. She is very playful and well behaved but after she got fixed she did become more agressive towards other dogs. She has been fixed for over a year now and her health is fine but her alpha female defintley kicked in afterwards.
Let us know what you find out! =]
Best of Luck!

Colleen,
this is not normal behavior for any dog. there are numerous possiblities that could cause this behavior.
---has she routinely (monthly) been around other "unkown" dogs? some dogs do great with "their" pack (normal play group at park) but don't tolerate unknown dogs.
----is she doing this behavior when "on lead"? some dogs get nervous when they can't control their escape & will become aggressive.
----has she had an injury or illness? i recommend a vet check to be sure there isn't any underlying illness or pain that could cause this intolerance.
good luck!'
Mary