If the problem is linked to the coat, the reasons mostly are inheritance or a deficiency
in certain nutrients. Pigment changes of the skin (nose, eyelids, lips and nails)
can be seen after whelping, in young dogs during the growth period and in a period
where the skin is not confronted enough with direct sunlight. The various causes
of loss of pigmentation of the nose (nasal planum) are : 1) Dudley nose, 2) Snow
nose (Labradors, Golden Retrievers, Bernese Mountain Dogs and Siberian Huskies –
seasonal: lighter in the winter and darker in the summer), 3) Vitiligo (may be part
of a syndrome of immune mediated disease in which hypothyroidism also occurs), 4)
contact dermatitis (plastic bowls), 5) Discoid lupus with pemphigus, 6) Squamous
cell carcinoma.
An overview of the most common conditions causing pigment or colour changes in general
are: acanthosis nigricans (Dachshund), adrenal sex hormone responsive dermatosis
(Pomeranians, Chows, Keeshonden and Samoyeds), apocrine sweet gland cyst (head,
neck and limbs), basal cell tumours (older dogs – head, neck and chest), black
hair follicular dysplasia / alopecia / dystrophy (Bearded Collies, Basset hounds,
Salukis, Beagles, Dachshunds and Pointers), Bowen’s disease (head, neck, shoulder,
forelegs, mouth and genital areas), Bruises , Castration responsive dermatosis (Chows,
Samoyeds, Keeshonden, Alaskan Malamute, Miniature Poodles and Pomeranians), Chronic
irritation/inflammation, colour dilution/mutant alopecia (Dobermans, Dachshunds,
Great Danes, Yorkshire Terriers, Whippets and Greyhounds), Cushing’s disease
(hyperadrenocorticism), cyclic (cicatrical) alopecia – seasonal flank alopecia,
demodectic mange, epitheliotrophic mange (mycosis fungoides), oestrogen responsive
dermatosis (Dachshunds and Boxers), follicular cyst (head, neck and trunk), follicular
dysplasia (Siberian Husky, Doberman Pinscher, Airedale Terrier, Staffordshire Bull
Terrier, Curly Coated Retriever, Irish Water Spaniel and Portuguese Water Dog),
growth hormone responsive alopecia (Pomeranians, Chow Chows, Keeshonden, Samoyeds
and Poodles – neck, tail and the back of the thighs), hemangiosarcoma, hyperestrogenism,
hypothyroidism, injection site alopecia, interstitial cell tumour, jaundice, lentigo
(Pugs), Malassezia, mast cell tumour, melanoma, Dudley nose (Yellow Labradors, Golden
Retrievers, Poodles and Dobermans), Pemhigus foliaceus, red/brown staining of hair
(tears and saliva), rocky mountain spotted fever, sertoli cell tumour, skin cancer,
tail dock neuroma, tail gland hyperplasia, uveodermatologic syndrome (nose, lips
and eyelids) and vitiligo (nose, lips and face).
Skin and coat health can be helped with supplementation of a complete formulation
containing all essential vitamins, minerals, amino-acids and fatty acids. To obtain
the best absorption and efficacy of those nutrients, a complete liquid formulation
such as Viyo Elite is the best guarantee.
Dr Wim VAN KERKHOVEN, DVM