My dog is allergic to flea bites. We moved to a new house where I guess we had fleas in our backyard, and he'd developed sores over half his body and an infection on his back leg from scratching himself. His hair was half gone too. His vet prescribed antibiotics for his infection, a new flea medication, and PrednisTab to stop the itching and heal his skin. I got all from vet depot and my dog is about 80% better and improving every day.