Many Americans enjoy the companionship of dogs; dog owners have even been touted in multiple surveys as being happier than those without dogs. Naturally, then, when Fido starts changing colour, you may be concerned. However, there are many possible reasons. The best course of action is to go to a veterinarian who can look for other symptoms and determine if there is cause for concern or treatment.
Melanin, the same pigment that causes the variations of colour in human skin, is present in dogs. As dogs age, the pigment cells in the hair follicles die. Fewer pigment cells mean less melanin in the hair strand and the lighter it appears. Your veterinarian can tell you if your dog's hair, particularly around the muzzle, is whitening at a "normal" time for its age and breed.
Vitiligo is a hereditary skin disease that causes patches of depigmentation on the face. The hair on the affected patches turns white. The depigmentation is complete 3 to 6 months after the disease onset. Possible causes include autoimmune disease, stress, infection and neurological factors. No treatment is available for vitiligo.
Systemic Lupus Erythematosus is an autoimmune disease in which the dog's body incorrectly identifies parts of itself as foreign and produces antibodies that attack it. Many variable symptoms exist for the disease, including fever, anaemia, kidney problems and skin disorders. Depigmentation is one of the symptoms for the skin, along with ulcers, alopecia, crusting, redness and seborrhoea. The exact cause of canine lupus is unknown, and although drug therapy treatment is available, remission is short lived.
Hypoparathyroidism is a rare endocrine disorder that has been linked to vitiligo in dogs. In this disorder, the parathyroid underproduces, which severely affects calcium regulation. Symptoms can be non-specific and include anorexia, nervousness, panting, diarrhoea, fever, thinness, stiff gait, weak pulse and cataracts. Treatment involves dietary changes along with calcium and vitamin D supplementation.