Articles Index/Dermatology
Posted 12/18/97

ICHTHYOSIS BULLOSA OF SIEMENS IN NORFOLKS

 

A PERSONAL ACCOUNT

Let me begin by saying I am not a scientist and this is not intended to be a scientific report. Rather, I hope that by sharing my personal experience with this hereditary disease I can alert other Norfolk breeders and owners to this problem. I want to make it perfectly clear that I am not trying to point a finger at any particular dog or breeder, nor am I trying to discredit anyone's breeding program. But I believe this is a growing problem and it must not be ignored. While only six Norfolks have been diagnosed to date (two of which are mine), these dogs are all fairly young and the problem seems to be increasing. While no exact mode of transmittal is known, it is a hereditary disease and may be an autosomal recessive trait.

At the time my first affected Norfolk was born, a male in 1993, we suspected no problem. We did notice some blistering around his ears within 24 hours of birth, but attributed it to the vigorous rubbing we had to perform to get him to breathe. Within a few days, the blisters had healed. By the time he was four to five months old, we'd noticed darkening of the skin on his stomach. He was diagnosed as having a staph infection and was treated accordingly.

During the next few months as we worked his coat to prepare him for the show ring, we noticed excess flaking skin and some dark patches under the hair on his chest and shoulders. This was accompanied by a very oily coat. At no time did he ever develop hot spots, chew himself, or lose hair. As a matter of fact, he continued to grow excellent coat.

Over the following few months various diagnoses and treatments were given. Primary seborrhea, sever hyperkeratosis and atrophy of sebaceous glands were diagnosed prior to skin biopsy being performed by a dermatologist at the Texas A&M Veterinary School. Dr. Bob Dunstan at Michigan State University gave us a definitive diagnosis of Ichthyosis. Because we were informed this was so very rare, and probably not hereditary, we bred the dam of this dog again. Note that in her first litter in 1992 this bitch produced three normal puppies, and a normal littermate to this dog in 1993. We decided to breed the bitch again because the odds were so favorable that this was not hereditary and we had so gorgeous puppies from her. Her last litter of two was born in 1995 and it was apparent at birth that one of the puppies was affected. Besides having blisters on her ears, her tummy was not the tender pink color that all breeders are accustomed to in a newborn. As she grew, her skin darkened and became flaky and the pads of her feet thickened and looked like a very old dog's feet - cracked and thick. a skin biopsy was done at six months of age and sent to Dr. Dunstan along with another biopsy from her older affected brother. This time Dr. Dunstan was able to diagnose the specific form of Ichthyosis as Ichthyosis Bullosa of Siemens. He supplied us with literature about the disease and verified that this is most definitely hereditary. Since my two have been diagnosed, four more Norfolks have been diagnosed by Dr. Dunstan in the past 12 months.

As I stated in the beginning, my purpose is not to discredit anyone, rather to alert the fancy to this problem. If anyone has had a Norfolk with dark, flaky and smelly skin, blisters on ears or pads of feet, you may be dealing with this problem.

Letter To the Editor From Marleen Grief
ANTIC, March, 1997

 

In January, 1997, following communication about this disease from Carol Falk, ANTA member and NNTC Genetics/Health Chairperson, ANTA President Ed Plummer contacted Dr. Robert Dunstan with an offer to publish an article about Ichthyosis in ANTA's newsletter. His response, which appeared in edited form in the March, 1997, ANTIC, follows:

 

DR. ROBERT DUNSTAN ON NORFOLK ICHTHYOSIS

Over the past 3 years, we have been diagnosing an unusual disease in Norfolk Terriers. The condition can be recognized shortly after birth because the lease amount of trauma results in small blisters, especially on the ears. As the animals age, the blisters become less conspicuous and hyperpigmentation (darkening of the skin) as well as scaling (dandruff) --especially of the underarms and groin areas -- become the most pronounced clinical findings. We believe that this disease represents a defect in the ability of the skin to form a normal stratum corneum, the outer layer of the skin that normally serves as a "Saran wrap"-like protective barrier. We call this disease "ichthyosis" because it is similar in many respects to a class of skin diseases in humans in which there are excessive scales that vaguely resemble those of fish.

Although the disease is not life-threatening, it is disfiguring. Affected dogs have dandruff entrapped in their fur and because the dandruff becomes colonized with bacteria and yeast, they often have a strong odor. There is no cure for Norfolk Terrier ichthyosis, only control. In most dogs, weekly baths with lipolytic compounds such as baby oil or Goop Hand Soap followed by washing with a dishwashing liquid may improve dogs to a tolerable level. Theoretically, a vitamin A analogue called Etretinate should be the treatment of choice, but this medication is quite expensive (approximately $20.00 to $30.00 per month of therapy), and to date, too few dogs have been treated to allow us to determine the cost-benefit ratio.

A preliminary pedigree analysis indicates that the disease is autosomal recessive. More disconcerting is that, to date, we have diagnosed ichthyosis in 6 Norfolk Terriers from around the country. This is a large number of affected animals in relation to the population of Norfolk Terriers as a breed and indicates that the gene causing ichthyosis must be fairly common. In other words, there must be a large number of carriers that are being used for breeding purposes. To date, we have not identified the disease in Norwich Terriers.

We are in the preliminary stages of investigating this disease at the molecular (DNA) level. If we are lucky, the work may go quickly. An almost identical disease known as ichthyosis bullosa of Siemens has been recognized in humans and if the Norfolk Terrier disease is truly the same, we can piggyback the work done in humans to help identify the gene that causes the skin disease. If Norfolk Terrier ichthyosis is not the same as ichthyosis bullosa of Siemens, identifying the gene will take much more work; however, once we are successful, we can develop a test using no more than a brushing of the gingiva that will allow us to distinguish carriers from normal dogs -- information that is imperative for breeders to eliminate the disease from their kennels. To this end, we have applied for funding through the Mark Morris Foundation and through the Pure-Bred Dog Endowment Fund at Michigan State University. At this writing, we are waiting to hear if our proposals will be approved for funding. [Editor's Note: Dr. Dunstan reported in February, 1997, that the Pure-Bred Dog Endowment Fund approved his grant for initial investigation and he hopes that the work will bear fruit within two years.]

Right now we are trying to identify as many Norfolk Terriers with ichthyosis as possible and to collect samples of skin, blood and gingival brushings from affected dogs and their littermates. Please contact us if you have an affected dog or even if you have knowledge of the disease. Dr. Credille and I will keep all contacts in the strictest confidence. Your name, the name of your kennel and the name of any of your dogs will not be divulged to others. I personally own a dog with ichthyosis (a Jack Russell Terrier named Riley) and Dr. Credille is currently getting her Ph.D. investigating Riley. Both of us know this disease firsthand and will be happy to talk to you if you need more information.

Please, if you know of breeders who come forward and admit the disease is in their kennels, do not criticize them. They are protecting your breed! Working with other genetic skin diseases has shown us that the degree of concern by breeders is always directly proportional to the frequency in which the disease is identified in their kennels. This is logical but unfortunate because genetic skin diseases are easiest to remove from a population when the number of animals carrying the gene is small.

We realize how frightening the announcement of a genetic disease can be to breeders. Perhaps because of this fear, there are three distinct phases associated with mobilizing breed clubs to action. The first phase is denial. This occurs when the disease is relatively uncommon. Expressions like "I have bred Norfolk Terriers for twenty years, have never seen an affected puppy and therefore it is not a problem" define this phase. During this period, it is difficult, if not impossible, to get breeders to breed away from disease because they do not feel it is a matter that concerns them. As the disease becomes more common, the "it is in someone else's line, not mine" phase begins. This also is a difficult time to organize a breed club because there are usually so many accusations and rumors that breeders often become pitted against each other, often to the detriment of the breed they love. Finally, there is the crisis phase. This occurs when almost every major breeding line has some dogs who are carriers of the disease. At this point, all breeders are willing to admit that the genetic disease is a problem because there is no stigma for coming forward. Unfortunately, by now it is very difficult to eliminate a gene so disseminated through the population.

We hope we're being alarmists but our belief is that Norfolk Terriers are close to the crisis stage. If we can help you in any way, please do not hesitate to contact us.

 

Robert W. Dunstan, DVM, MS, DACVP
Kelly M. Credille, DVM, DACVP
Department of Pathology
G-300 VMC
College of Veterinary Medicine
Michigan State University
East Lansing, MI 48824

 

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