Kyla got spayed on Tuesday morning and she since then she seems to be EXTRA aggressive towards other dogs. Before she might raise hair a bit but if I said "enough" she would calm down. Once she has been introduced to another dog then she was more interested in playing. Now though, woah! She sees another dog down the street and her hair is up from neck to nub and she is barking, growling and jumping trying to get them.

Its like she is a different dog
Is this because of her feeling vunerable after her surgery? A sort of defence mechanism of sound loud and scarey to keep them away when she is not feeling well? Anyone else had similar experience at all??