Ringworm or something else?

Hi vets. We brought our puppy home almost a month ago. Shortly after I found a crusty patch of skin. When I asked the breeder, she mentioned it could be ringworm since they had treated a cat on the property for that in the weeks prior. I’ve been treating with lotrimin and medicated shampoo just in case - today it looks like a bald patch of skin. Does this look like ringworm or something else like a hot spot? It doesn’t seem to bother him at all and I haven’t noticed him itchy it or biting at it (it’s on his hip area). Thanks!

Hello!  You're right, something like this could be ringworm, but could also be a number of other things including demodex mites, or simply a pulled away foreign body, sticky spot or 'matt' in the hair, or superficial bacterial / yeast infection.  There is no technical definition of a 'hot spot' - it could refer to any itchy or red spot on the skin, so you likely had one.  In older dogs ( and some unlucky young ones), hair loss can also be connected to underlying hormonal disturbances .  Good to note the use of gloves in the pictures (are all these of the same dog?  The hair colour looks decidedly different) and of course, the right thing to do is to show the lesion to your vets for diagnosis before trying any treatments.  Ringworm treatment, for example, won't touch a demodex lesion or hormonal lesion - nor will demodex treatment touch any form of ringworm and no drug is without potential side effects, so they need to be used appropriately.  Best of luck!

Hello, did you ever figure out what this spot on your puppy was? I have something nearly identical on my young dog, and I've also seen him itch or bite at it.