Oh my gosh. I bought Maxi in January @ 12 weeks old and found she had fungus. She has been treated for ringworm for about two months now with fulvacin. It is a liquid that costs about $75.00 per bottle and I have bought 4 of them and she still has it. I caught it from her and so did my other dog. It doesn't affect their health unless they get a secondary infection. It is very contagious. I wash the floors with bleach water and the spores can live for a very long time in the carpet.
Puppies are most likely to get it. It is not a worm but a fungus. I hope the seller takes into concideration what you will be investing in treatment for the new puppy. My breader didn't acknowledge she had it when I purchased her but her spots were small at the time and I couldnt see them untill I really looked.
It has been a real headache, but I love her and am hoping for the day when she has a full coat of fur and the bald spots and scaling are gone.
Maggie, Maxi and Vea