My 1 year old yorkie is out of control!! HELP!!

Question
I have a 1 year old female yorkie! She had her female surgery, and after that she has completely changed we dont know what happened. She lays her ears back and growls and bites you if you do something she doesnt like, for ex. if she is asleep and you start talking to her and walk over to pick her up she growls at you and tries to bite you. She has been doing that quite a bit here lately. Also when you go to leave it is a fight to catch her to put her in the bathroom(where we keep here when we leave.) I really need help, she has started biting my family more and more. We just want our little sweet dog back.

Answer
First, have her thyroid level checked as hypothyroidism can cause aggression in some dogs.

I really do think, however, that your dog is just a spoiled brat who is used to having her own way... think DOMINANT. Get her into ongoing obedience classes (several months), work with her every single day, and everyone in the family must start practicing "Nothing in Life is Free" with her. http://k9deb.com/nilif.htm  She must WORK for every single thing she wants in life.... be it food, petting, jumping up on the furniture... EVERYTHING. If she is up on the furniture, tell her to GET DOWN and then sit where she was. If she doesn't move, pretend to sit on her (and I HAVE sat on more than a few who chose to not move... gently, of course... we don't want totally squished dogs).

Spaying, by the way, had absolutely nothing to do with this attitude change. When she became an adolescent at 7-8 months, she decided to take control because she did not see a pack leader in the house. Your family members need to learn to assert themselves over her. If you are not capable of doing that on your own, you need to call your vet for the name of a qualified animal behaviorist in your area.