Where doesn't my dogs hair grow?
After extensive tests, it was discovered that she had a very rare skin condition called "Colour-Mutant alopecia". It is passed from parents to offspring and results in brittle patchy hair over the chest.
For the more technically minded, colour mutant or colour dilution alopecia is a relatively uncommon, hereditary, atrophic dermatopathy associated with abnormal clumping of melanin, and dystrophic growth of hairs. It is characterised by variable alopecia and poor coat quality in blue and other colour-diluted breeds of dogs. Skin changes are limited to colour-diluted, usually blue hair, with sparing of tan points. Typically, there is a gradual onset of a dry, dull, brittle hair coat with hair shafts fragmenting and poor hair regrowth. Hair loss, and formation of comedones are usually most severe over the trunk, and hyperpigmentation may occur with chronicity.
This dog developed symmetrical hair loss (Alopecia) as she grew older