I've worked and volunteered at 3 shelters during the past 5 years. I've been around SO many sicknesses, almost every one in the book, and never brought one thing home to my dogs or cats. I even constantly take in fosters, but I'm careful with quarantine so my animals don't get sick from the fosters either.

I have shelter shoes that I keep in my trunk. I just bring along an extra pair of shoes to put on after I take the shelter shoes off and throw them in the trunk. I also throw my clothes directly into the washer. I don't always take a shower when I get home, but I usually do. While I'm at the shelter, I disinfect my hands and arms between each animal anyway.