Here's what I found:
Pictures of Yorkies with ringworm:
http://www.brisbio.ac.uk/ROADS/subje...reterrier.html
Treatment:
RINGWORM
This is a common problem in the 1st 4 months of a puppy's life. The spores are usually picked up on grass with terrible effects.
Check regularly from 5 weeks - sit in the sun and check for dandruff flakes. When you catch it when it's small it is easier to care for, but if you only realize that there is some ringworm when the hair is falling out, and it's the size of a 50cent piece, it's usually spread already. Treat it with 1% lamisil spray 3 times a day, followed with tinaderm cream, and don't stop until the hair is at least 3mm long again. An eighth of a microcidal tablet must be given for 24 days at least. So do get 3 tablets from your chemist and please make sure not to overdose.
http://www.yorkiesparadise.com/Care.html
More info:
How is ringworm spread?
T. mentagrophytes is thought to be contracted from exposure to rodent nests, and M. gypseum from contaminated soil, though the potential also exists for spread from animal to animal in a contaminated environment. M. canis is most often spread from contact with an infected animal or a contaminated environment, and therefore is by far the most likely to be a serious problem in a shelter.
Ringworm is very durable in the environment. Ringworm can persist in carriers, furniture, carpets, dust, heating vents, furnace filters and the like, and can infect animals housed in a contaminated environment months and even years later. It can be spread readily on grooming implements, contaminated toys and bedding, or by humans on clothing and hands. It can be found on the hair of animals from a contaminated environment even when the animal itself is not showing any signs. In nature, the incubation period for ringworm is between 4 days and 4 weeks.
http://www.vetmed.ucdavis.edu/ccah/P...d/ringworm.htm