Poor hair coats and alopecia that are not a result of inflammation or pruritus and are symmetric or involve much of the body most commonly reflect a disorder of hair growth that is metabolically or genetically related. In general the disorders will fit into one of four categories.

Nutritional/Metabolic

Inadequate intake or utilization such as results from malabsorption or liver disease
     • protein,
     • fatty acids
     • zinc
     • vit A
     • Endocrine
          o Hyperglucocorticism
          – Natural pituitary dependent, adrenal tumor
          – Iatrogenic
          o Hypothyroidism
          o Hyperestrogenism
          – Gondal, iatrogenic, neoplasia, adrenal
          o Hyperprogesteronism
          – Gondal, iatrogenic, neoplasia adrenal
     • Follicular dysplasia
     • Endocrine Modulated
          – Alopecia X–Adrenal syndrome-Atypical cushings
          – Castration responsive –
          – Canine cyclic flank alopecia
          – Siberian husky and Malamute follicular dysplasia
          – Irish Water Spaniels
          – Chesapeake Bay retriever (CBRS)
     • Non Endocrine Modulated
          o Abnormalities in Melanin transfer or production
          – Color dilution alopecia (CDA)
          – Black hair follicle dysplasia (BHFD)
Congenital Malformation of hairs
          – Hairless breeds
          – Congenital hypotrichosis
          – X linked ectodermal dysplasia
          o Post Clipping Alopecia
          o Follicular lipidosis of rottweilers
          o Pattern alopecia
          o Pinnal alopecia
          – Pinnal alopecia
          – Caudal pinnal, ventral and thigh alopecia
          – Non-classic, curly coated retriever, American water spaniel and Portuguese water dogs
     • Keratinization/epithelialization
     • Primary idiopathic seborrhea
     • Sebaceous adenitis