I have heard that pugs are prone to having skin allergies. But if you suspect your dog may have fleas at all, you should definitely treat it for fleas with frontline or advantage/advantix. I woudlnt' immediately suspect ringworm unless your dog has a lot of contact wtih other dogs and their poop especially. You can take the dog to the vet and have a skin scraping done to check for parasites to be on the safe side though. Also, feeding cheap and low quality dog foods can contribute to skin problems.
Do you already have a pug puppy, & does your puppy already seem to have some skin problems? Ring Worm is actually a fungus that grows on the skin - it is commonly found in soil, so can be picked up just about anywhere. Some animals & people are more susceptible to becoming infected with it. If your vet suspects ringworm they can do a culture to confirm diagnosis.
Thank you all for youe replys..I do have a male pug puppy he is 15 weeks old and full of life..He eats Iams puppy food since he could eat, and he gets bathed and i dont find lots of fleas on him but i am still interested in hearing anything anyone has on pugs and thier skin
After seeing a vet of course, I would bathe any dog with any skin problems in medicated tar/sufla shampoo. Most pet supply stores carry it or can order it. I have groomed many dogs. This always seems to soothe the area and helps to promote healing. When grooming a dog with flea this shampoo is also great after the flea bath and before the dip. It helps relieve the itching.