A very different behaviour

Question
Hi,

My pet(Pomeranian female dog) is almost 9 years old. She used to be a very nice and very friendly with all my family members. And believe it or not she never touched and ate the non-vegetarian food. Though she is a good hunter and killed small cats, rats, lizards etc but never ate them, instead after killing she throw them outside the campus. But recently ,something has happened. She started growling and snapping to my Mom and others. One very peculiar change is recently she killed one cat and instead of throwing out of the campus, she started eating it and sucking her blood(yuck...yuck). It's disgusting. Could you please guide me what may be the reason for this sudden change.

Answer
I saw your original question in the answer pool after somebody else didn't feel they had a good answer.  I didn't answer it thinking I didn't have the best answer either.  I will do what I can.  Such a behavior change is unusual in a dog of that age.  The first thing I would do is have a vet carefully check her over.  Let him know about the problem.  There could be a physical change causing it.  

She needs stronger leadership too.  The key to most behavior problems is approaching things using the dog's natural instincts. Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog. Life is much easier if the 2 legged pack members outrank the 4 legged ones. You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/ For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm

Your mom and everybody needs to act the role of top dog.  They are all higher status and go through doorways first, get the best seats, eat first, etc.