"rookie" had a spot (missing hair) on his tail when i purchased him as a puppy. a quick trip to the vet and an anitbiotic cleared it right up. no other major problems until around 3 months ago (he is 2 1/2 yrs old now) he started to get really bad bumbs all over his back and sides. well the bumps ended up scabbing over and made his hair fall out (probably lost 25% of his coat). tried the same antibiotic as last time but it didnt seem to help. Got a second opinion and this vet diagnosed it as a fungus (more than likely he got it from a lake he sometimes swims in). but 2 weeks on an anti-fungal med cleared it right up. his coat is almost completely back to normal. just glad it did not leave any scars or anything.