My 11 1/2 year old cat has a wound on her head that does not seem to heal. For over 2 years, I have gone back and forth to our local vet, and have used antibiotics and various other methods of wound care to nurse her back to health. We seem to make progress, and then it starts again. Lately, I've noticed that she has several spots on top of her head, and a new one on her face on the side of her nose (next to her eye). They are small and pussy. Any thoughts as to the cause?