Common diseases and parasites pass between pets and humans?

Oh, yes! Ringworm. It's a skin fungus, an "kissing-cousin" to athletes foot. Many years ago I took in a stray kitten that had some scaley patches on it's skin. I just figured it had gotten beat up bu a larger cat. The summer was hot and my cats were cranky, and they developed scaley patches everywhere they had "scored" on each other. I had an infestation of spiders in the basement, so when I developed scaley patches on my arms, I thought I was alergic to spider bites. When I took one of my cats to the vet, she said, "It's ringworm. And it looks like you have it too." So for the next couple of months, I was anointing my cats with a Miconozol Nitrate lotion and rubbing Micotin creme on my rash, and doing a LOT of clothing and bedding laundry. Eventually it cleared up.

It is not life-threatening, but it is EXTREMELY contagious, and the spores that spread it can linger in the environment. Any warm-blooded animal can catch (and pass) it. Isolating the affected animals and disinfecting their living quarters with bleach water is also part of getting rid of it.

By the way, the term for diseases and such that can be spread from animals to humans and vice verse is "zooanotic (sp?). It also includes Lyme disease, and mange (called "scabies" on a human).