I have two papillons that are prone to "hot spots". We adopted our second one last September and his hind end was a mess. It cleared up nicely but I would like to keep it from happening again. They are both scratching like crazy. We live in SoCal. Could diet play a part?
Just like humans, dogs can suffer from a vast array of allergies from mild to severe with a wide range of reactions. Food can certainly play a large part in skin problems, itchiness, ear problems, etc... I am no pro at what a good diet for the little guys might be, but there are common allergens to watch for in any food. Here are some of the most common; wheat, corn, beef, dairy products (including eggs), chicken, lamb, fish.
I'd check with the vet, but in the meantime, you might want to try switching things around..if you're feeding beef & wheat, try chicken & rice...eliminate products one at a time, check for improvement. Unfortunately, unless you pay for allergy testing, it is a matter of trial and error and treating the symptoms along the way.
Make sure there isn't a case of insect (fleas, mosquitoes, chiggers, etc..) bites.
"Some days you're the dog; some days you're the hydrant". author unknown
I would take them into the vets and have a skin scraping done. Sounds like a good possibility of Mange mites. All dogs have the mites, but when an immune system is immature or comprimised...the mites can over populate and cause "hot spots". Hope this helps.
When our Saints dealt with hot spots we would first give them a quality dry kibble. Then treat the spots: cut the hair around it, clean with Betadine then apply some hemmeroid cream to cool it. It has always helped. We also use Frontline on them to keep any itchy fleas off of them. Good Luck!