I had cats when I was younger (born in the 60's) and after a fight, they'd lick themselves clean, never needed a vet, never had vaccinations either! I've only had cats since then for the last couple of years and they constantly need the vets. Every bite seems to get infected. Vets always say it's likely another cat. I live on the edge of town and there's a lot of cats around here.
I can't keep them in as they are too used to going out. I've stopped them being able to use the cat flap to go in and out at night now but still they get into fights. They are healthy cats otherwise, no underlying health conditions etc.
I'm wondering if constant vaccinations somehow weakens their own immune systems. Also, constant antibiotics can't do much good either. Any theories on this anyone?