Chances are you have nothing at all to worry about. Most zoonotic diseases that humans can get from dogs (or other animals) are intestinal and are transmitted by the humans handling contaminated feces. There are also skin parasites like mange mites, but you don't have to worry about these unless your dog has mange, and you would definitely know whether or not your dog had mange. If you would feel more comfortable about it, you can put some peroxide on a cotton swab and dab it onto the scratch, but unless your immune system is compromised for some reason, you shouldn't have a thing to worry about.
Ghilly
Sure, but you could also get an infection just because his feet are dirty ... because they are feet.
Have you talked to his breeder or other GP owners to see if this is common problem with them?