What other symptoms your dog is showing? Is she scratching and chewing? Hair loss in dogs of all ages can be due to itching and scratching. There are many irritants which cause this itching. Major irritants that itching and hair loss in dogs are allergic reactions and some diseases. Dogs lose hairs due to following allergic reactions.
- Flea allergy
- Food allergy
- Pollen allergy
- Mold allergy
- mange
- Lice infestation
- Ringworm infection