2. Infection or Infestation
An infestation with parasites such as fleas, ticks, and mites (scabies, mange) is another source canine alopecia. Along with hair loss around the ears, eyes, abdomen, and chest, signs your dog may have mites or fleas/ticks include inflammation, itching and redness. Bacterial or fungal infections, such as in the case of ringworm (which is actually a fungus), can also be attributed to hair loss in dogs. Symptoms of ringworm include circular or irregular hair loss, inflammation, and infected crusts.