If you have a cat, do not immunize him EVERY YEAR!
My cat was just diagnosed with a golf ball sized malignant tumor right where his injection site was from only a month ago. The vet suspects in one more month, the tumor will be the size of his head.
It comes from these fvcking immunization shots, and you don't need to do them every year. Should be every 4 years.
Look up Vaccination-Associated Fibrosarcomas (VAS) tumors on google and you'll see what the deal is all about and how it's caused by these excessive vaccination shots. My cat is VERY healthy for his age (12) and I thought this lump on his shoulder was odd. Figures it only started developing a few weeks after his last shot.
Just a warning.