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