What is breed of your dog? Some breeds like Yorkshire terrier has very sensitive skin and is more prone to develop skin allergies. Hair loss in dogs can be due to flea allergy, allergy to pollens, molds, and foods, scabies especially sarcoptes mange, Cheyletiella or lice which causes pruritus, pyoderma, ringworm infection, Cushing's disease, endocrine diseases due to hormonal imbalances, autoimmune skin diseases and almost all skin diseases. As hair loss in dogs always indicates some underlying cause, so, it should not be taken easy and a visit to vet for accurate diagnosis and treatment is necessary.
