Page 1548 - Clinical Small Animal Internal Medicine

1486 Section 12 Skin and Ear Diseases

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Figure 168.8 Zinc‐responsive dermatosis (syndrome I) in an adult
Siberian husky. Crusting, erythema, alopecia, and
hyperpigmentation of the periocular skin are present.

deficiency is unlikely in a patient eating a well‐balanced
Figure 168.7 Two‐year‐old boxer with visceral leishmaniasis diet. Relative deficiencies can be seen in dogs when zinc
caused by Leishmania chagasi. The skin lesions are generalized and absorption is impaired by excessive amounts of other
characterized by erythema and thick scales adhered to the skin nutrients.
surface and hair shafts. Source: Courtesy of Dr Romeika Reis Lima.
Syndrome I zinc‐responsive dermatosis occurs in dogs
eating a well‐balanced diet and has been reported most
commonly in Siberian huskies and Alaskan malamutes.
zygomycosis. More specific tests include serology for
anti‐Lagenidium antibodies, culture, and PCR testing. A more severe form has been reported in a litter of
The prognosis for dogs with systemic lagenidiosis is pharaoh hounds. Skin lesions usually begin in early
grave. For dogs with only cutaneous lesions, aggressive adulthood and consist of early erythema followed by
resection can be curative and amputation can be consid- crusting, scaling, lichenification, and alopecia. The dis-
ered for those with distal limb lesions affecting one leg. tribution is typically around the mouth, chin, eyes, and
Radiography of the thorax and ultrasonography of the ears (Figure 168.8). An inability to absorb zinc from
abdomen is recommended prior to surgery because of the gastrointestinal tract has been shown in some
the frequency of systemic dissemination. Medical ther- malamutes.
apy with antifungal drugs is typically ineffective alone but Syndrome II zinc‐responsive dermatosis has been
has been described as an adjunct to surgical resection. reported predominantly in large‐breed puppies or young
Many other infectious diseases can present with adult dogs eating diets deficient in zinc or diets that
cutaneous manifestations. This list includes canine interfere with zinc absorption (e.g., excessively high in
herpesvirus infection, pseudorabies, feline infectious calcium, other minerals and vitamins, or phytates). Dogs
peritonitis, feline calicivirus infection, toxoplasmosis, with this syndrome have extensive crusting and fissuring
neosporosis, brucellosis, pythiosis, entomophthoromy- of the footpads and nasal planum, and generalized crust-
cosis, and rickettsial and ehrlichial infections in dogs. ing plaques. Very similar but more severe clinical signs
have been seen in generic dog food dermatosis, which
was seen in North American in the 1980s but was
Nutritional Disorders Causing virtually eliminated with the reformulation of these
Cutaneous Manifestations foods. In this syndrome, a deficiency of multiple nutri-
ents is likely and more severe systemic signs are present.
The diagnosis of zinc‐responsive dermatoses is made
Zinc‐Responsive Dermatosis
by clinical signs, dietary history, and histopathologic
Zinc‐responsive dermatosis is an uncommon skin dis- findings.
ease in dogs. It includes syndromes caused by nutrient The treatment of syndrome I zinc‐responsive derma-
deficiency, nutrient imbalances, and the inability tosis consists of oral zinc supplementation. Most cases
to absorb or utilize zinc. Absolute nutritional zinc respond well within 4–6 weeks, but require ongoing