The most common cause of shedding is scratching. And such scratching might be because of excessive itching and licking in dogs. Thus some of the factors that contribute to skin shedding are:

Skin disease: It might be that the pet is suffering from some skin disease or skin allergy which causes excessive itching and/or shedding in dogs. All kinds of skin allergies and diseases have the common symptom as shedding.

Skin allergy: Dogs might be allergic to pollens, molds and certain food items. This may cause shedding and itching in dogs.

Allergy to fleas: This is one of the leading causes of shedding.

Autoimmune skin diseases: Autoimmune skin disease in dogs might lead to shedding. In such a case, it is vital to consult the veterinarian at the earliest.

Lice: Lice might also cause itching and irritation in skin. This may lead to scratching and thus shedding of skin or dander.

Other common causes: Some other common diseases and infections seen in dogs are pyoderma, ringworm skin infection and endocrine disease. This can also lead to shedding. If your dog is not having any such mentioned skin infection, skin parasites then there might be some internal cause for shedding. In such a case, vet’s advice would be apt.