Ichthyosis and Dogs
What is ichthyosis? This is a rare condition in which there is marked thickening of the outer layer of the skin and of the footpads. Affected dogs have rough skin covered with thick greasy flakes or scales that stick to the skin and hair.
How is ichthyosis inherited? The mode of inheritance is likely autosomal recessive.
What breeds are affected by ichthyosis? This is a rare condition that has been seen mostly in the West Highland white terrier, and has also been recognized in the Cavalier King Charles spaniel, Doberman pinscher, Jack Russell terrier, Norfolk terrier, and Yorkshire terrier.
For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed.
What does ichthyosis mean to your dog & you? Affected dogs have abnormal skin at birth and the condition worsens with age. The skin is rough and covered with thick greasy scales, some of which tightly adhere to the skin and hair, and some of which are shed in flakes. The dog's general health does not appear to be affected, but the skin changes are chronic and severe. West Highland white terriers may be born with black skin that cracks and peels at 2 weeks of age. Because of the marked thickening of the footpads, the whole paw may appear enlarged and the feet may be painful.
How is ichthyosis diagnosed? In a young puppy, the changes are typical of ichthyosis. If these changes are seen in an older dog, other causes of seborrhea must also be considered. In either case, the diagnosis is confirmed through a skin biopsy. This is a simple procedure done with local anesthetic, in which your veterinarian removes a small sample of your dog's skin for examination by a veterinary pathologist. The biopsy will show changes characteristic of this condition.
How is ichthyosis treated? It is possible to manage the condition in affected dogs, but it requires great diligence on the part of owners. Your veterinarian will work with you to find what is most helpful for your dog. Treatment will include frequent mild anti-seborrheic shampoos and moisturizing rinses. Due to the chronic, severe, incurable nature of the skin changes and the intense treatment required, many owners choose to have dogs with ichthyosis euthanized.
For the veterinarian: There has been some success with the use of synthetic retinoids for treatment of ichthyosis. (See reference below).
Breeding advice Affected dogs, their parents (carriers) and their siblings (suspect carriers) should not be used for breeding.
FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.
Scott, D.W., Miller, W.H., Griffin, C.E. 1995. Muller and Kirk's Small Animal Dermatology. p. 745 W.B. Saunders Co., Toronto.
Power, H.T., Ihrke, P.J. 1995. The use of synthetic retinoids in veterinary medicine. In S.J. Ettinger and E.C. Feldman (eds.) Textbook of Veterinary Internal Medicine. p585-590. W.B. Saunders Co., Toronto.
Information used with permission from: Crook A et al. 2011. Canine Inherited Disorders Database (CIDD).