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Zinc Responsive Dermatosis is a skin disorder that responds to treatment with zinc. It is one of the manifestations of zinc deficiency. The deficiency can be dietary, or in some Arctic breeds, Samoyeds being one of them, it can be an inherited disorder of zinc absorption.
Signs and Symptoms
Initial symptoms are thick scaly/crusty patches and alopecia (hair loss) around the eyes and muzzle. This can also be seen on the ears, hocks, under the pads and around the reproductive organs in both dogs and bitches. Thick crusting occurs on pressure points, e.g. elbows. Hair may be dull and harsh and secondary skin infections can occur. Many dogs will scratch or chew at affected areas due to itching. Symptoms may occur at any age, but typically are first seen in young adult dogs.
Extended zinc deficiency can cause other problems, including lack of appetite and ensuing weight loss, slow wound healing, keratitis (inflammation of the cornea) and conjunctivitis (inflammation of the conjunctiva – the tissue that covers the inner eyelid and the white of the eyeball). Lymphadenopathy (enlarged lymph nodes) can occur in very young dogs.
There can be several reasons for zinc deficiency:
- Feeding incomplete feeds with insufficient zinc
- Over feeding other mineral supplements, especially calcium, iron and copper
- Feeding excess phytates, a substance found in some cereal-based diets that interferes with zinc absorption in the intestine
- Malabsorption, commonly thought to be a recessive, inherited disorder in Arctic breeds
- Related dogs with disorder
- Arctic breed (Samoyed, Alaskan Malamute, Siberian Husky)
Skin problems are generally hard to diagnose but this one has definite changes that can be easily recognized. Diagnosis can be made by microscopic analysis of a punch biopsy of the skin. This biopsy can be done under local anesthetic. The diagnosis is confirmed by the dog’s response to zinc supplementation.
Note: Treatment of animals should only be performed by a licensed veterinarian. Veterinarians should consult the current literature and current pharmacological formularies before initiating any treatment protocol.
If the cause of the zinc deficiency is dietary, an improvement in diet and short term zinc supplementation can usually bring improvement in a month or two.
If the cause is hereditary, the zinc supplementation will usually relieve symptoms, but may have to continue lifelong. Zinc can be administered by mouth but care must be taken not to overdose an affected dog as zinc poisoning can occur. The correct dose must be determined for each dog. Larger doses can cause vomiting. If large doses are needed, they can be divided and given, with food, several times a day. In some cases zinc is given intravenously. Once a correct dosage is determined with the aid of your Veterinary Surgeon, it will probably have to be maintained for the life of the animal.
Symptoms will recur if the supplementation is not maintained. Even as little as one missed dose can cause recurrence. Symptoms may occasionally flare up whilst supplementation is being administered. If this happens, they are usually of a short term duration, 2 – 3 weeks, and generally resolve spontaneously as long as the maintenance dose is still given.
Antiseborrheic shampoo can be used for relief of affected areas, but care must be taken when using around the eyes. Topical relief such as Aloe Vera gel for immediate relief can be used, although sparingly.
The gene(s) responsible for poor absorption appear to be recessive, but there are as yet no genetic markers in evidence in any of the affected breeds. Spaying females with the disorder has been reported to allow some owners to decrease, or cease zinc supplementation.
- Canine Inherited Disorders Database
- Colombini S, Dunstan RW. Zinc-responsive dermatosis in northern-breed dogs: 17 cases (1990-1996). J Am Vet Med Assoc. 1997 Aug 15;211(4):451-3.
- Tim D. G. Watson. Diet and Skin Disease in Dogs and Cats. The Journal of Nutrition Vol. 128 No. 12 December 1998, pp. 2783S-2789S
- White SD, Bourdeau P, Rosychuk RAW, Cohen B, Bonenberger T, Fieseler KV., Ihrke P, Chapman P, Schultheiss P, Zur G, Cannon A, Outerbridge C. Zinc-responsive dermatosis in dogs: 41 cases and literature review. Veterinary Dermatology, Volume 12, Number 2, April 2001 , pp. 101-109(9).
- Skin Diseases of the Dog and Cat: Clinical and Histopathologic Diagnosis by Thelma Lee Gross
No relevant support groups have been found to be available at this time.
Zinc Deficiency in the Siberian Husky from the Siberian Husky Health Foundation
Canine Zinc-Responsive Dermatosis by Carlo Vitale, DVM, Dipl. ACVD on the dvm360.com website. This article contains some photographs.