Your dog needs to be investigated for allergies and skin diseases including autoimmune skin diseases. This can be done by the vet because he is in position to have physical examination and laboratory test to confirm diagnosis. Scratching in dogs can be due to itching and irritations and many factors can cause these itchy skin conditions. Most common are
1. Lice infestations
2. Scabies
3. Ringworm
4. Pyoderma
5. Allergy to flea, pollens, molds, dust, food,and insects bite
6. Contact allergy
7. Endocrine diseases
8. Autoimmune skin disease
9. Cushing's disease
So, take your dog to vet for diagnosis and treatment.
1. Lice infestations
2. Scabies
3. Ringworm
4. Pyoderma
5. Allergy to flea, pollens, molds, dust, food,and insects bite
6. Contact allergy
7. Endocrine diseases
8. Autoimmune skin disease
9. Cushing's disease
So, take your dog to vet for diagnosis and treatment.