Food Allergy

• Meat, dairy, wheat or additives in dog food can trigger an allergic reaction. Your pit bull may chew at its legs or rump within 30 minutes of eating, and begin to lose hair and develop scaly patches of skin or even sores in the chewed spots.
  
  

Environmental Allergy

• Dust, mold, pollen and dust mites can cause sores and hair loss as the pit bull's immune system kicks into high gear to eliminate what it perceives as a toxin, producing itchiness as the "toxin" filters through the skin. It's likely you're dealing with an environmental allergy if your pit bull develops hair loss and sores at certain times of the year, such as in the spring.
  
  

Parasites

• If you know your pit loses hair and develops sores when fleas are present, be proactive; begin treating the dog with flea repellent before warmer weather draws out parasites. If you live in a region with warm weather year-round, consider presumptively treating for fleas to avoid an infestation.
  
  

Treatment

• Veterinarians test for food allergies, singling out various foods to avoid and creating a diet that doesn't include those substances; however, some allergies are tenacious, producing a skin reaction in pit bulls from substances not previously problematic. Veterinarians recommend adding variety to the dog's diet, alternating lamb with chicken or other meat sources that don't produce an allergic reaction. Cortisone shots or anti-itch medications can reduce skin inflammation and rash, but to treat hair loss, eliminating the allergen is your best bet.
  
  

Prognosis

• Identifying and treating allergies can be difficult, according to Rescue a Pit Bull.com: "With our dog we were able to eliminate the food allergies, which decreased her reaction to the other allergens in the environment. We continued to need sporadic cortisone shots for her during certain seasons," the website says.