Definition of Alopecia
Hair loss, technically called “alopecia,” is broadly defined as any deficiency in a dog’s normal hair coat. Alopecia doesn’t refer only to hair loss; it also includes coat defects from failure of hair to grow in the first place. Many medical conditions involve hair loss, including color dilution alopecia, seasonal flank alopecia, alopecia X (“black skin disease”), acanthosis nigricans, follicular dysplasia, congenital hypotrichosis, pattern baldness and pituitary dwarfism. Some have a genetic component. External parasites, fungal and bacterial skin infections, certain drugs, hormonal/endocrine imbalances such as Cushing’s Disease, Addison’s Disease, hypothyroidism, hyperthyroidism, allergies, stress, poor nutrition, lactation and cancer can all cause hair loss, with or without redness, itchiness, scabbing, scaling or bleeding. Because hair loss typically is associated with an underlying medical disorder, annual veterinary examinations can help identify and manage the problem before it becomes out of hand. These tests are especially important for older dogs.