Cerebellar Degeneration in the Gordon Setter

Thank you to Jerold Bell DVM for allowing us to reprint this article.

Jerold S Bell DVM, Tufts Cummings School of Veterinary Medicine, N. Grafton, MA USA

puppy by Silvia Timmerman
Photo by Silvia Timmermann

Cerebellar Degeneration CD (also referred to as Cerebellar Cortical Abiotrophy CCA, or Cerebellar Ataxia CA) is a hereditary neurological disease seen in the Gordon Setter breed, and caused by a simple autosomal recessive gene. It causes slowly progressive muscular in-coordination, with an onset or age of recognition of clinical signs between six months to four years of age. Pathology studies performed in the 1970’s show the onset closer to six months of age; but with mild clinical signs affected dogs may not be identified until later in life. CD is not related to the metabolic disorder lethal neonatal encephalopathy (DUNG’d) seen in 3 to 8 week old Gordon Setters.

The clinical signs of CD include: poor balance, frequent stumbling, a wide-based stance (feet planted far apart), a high-stepping gait, and head or body tremors. Affected dogs have normal mental alertness. Most affected dogs have a normal life expectancy, and pass away due to unrelated causes. There is no treatment for CD.

Drs. Alexander de Lahunta, Linda Cork, and Steven Steinberg published the clinical description and mode of inheritance of CD in the breed in the early 1908’s. In 2012, Dr. Natasha Olby at North Carolina State University identified the mutated gene. With autosomal recessive inheritance, both parent must be carriers of this mutated gene to produce affected offspring. Approximately one-quarter of offspring from such matings are expected to be affected; but statistical chance can cause none to several affected dogs in a litter. A genetic test is available for this mutated gene that will determine normal, carrier, or affected status. The test can be run at any age with cheek swabs, and costs $15 (US) per dog tested. (Submit DNA for Testing – NC State Veterinary Hospital).     (Link to form for submitting DNA for testing)

Gordon Setters affected with CD have been identified since a least the 1960s in both conformation and field trial lines throughout the United States, Canada, Europe, and Australia. Affected and carrier Gordon Setters worldwide do not “connect up” before generationally early ancestors of the breed. All confirmed affected Gordon Setters around the world have the identified mutated gene causing CD. This same mutation was identified in Dr. Olby’s laboratory to be the cause of CD in the Old English Sheepdog breed – showing a common ancestor as the original source of the mutation in both breeds. No other breeds have been identified with the same mutation to date.

Over the years, Gordon Setter breeders and owners have been surprised by a diagnosis of CD in their dogs, due to a lack of known relatives with the disorder. These occurrences are traditionally followed by more affected dogs from related lines. The ancestrally ancient origin of the mutated gene explains this occurrence. The mutated gene has been dispersed and propagated in the Gordon Setter breed since its origination. Now that there is an inexpensive and accurate genetic test for the mutated gene, ALL breedable Gordon Setters should be tested.

As with all testable simple autosomal recessive genes, quality carrier dogs can be bred to quality normal-testing mates. This prevents affected dogs from being produced. Quality normal-testing offspring should replace the carrier parent for breeding. Carrier offspring should be selected against for breeding homes. In this way, you have eliminated the single mutated gene, without losing the quality traits of the line. A genetic test for a simple recessive disorder should not change who gets bred, only who they get  bred to.

To assist breeders with health-conscious breeding, each dog’s results should be entered into the OFA Cerebellar Degeneration registry (OFA Form for submission of DNA). The test results will be listed on the dog’s OFA page. The cost is $15 per dog, $30 litter of 3 or more, and a kennel rate of $7.50 per dog if 5 or more dogs are entered by the same owner (all in $US). If a dog is out of two DNA tested clear Gordon Setter Parents, the OFA will provide a Clear by Parentage (CBP) certification. In this way, generations of Gordon Setters do not have to be tested.  CBP certification requires that both parents are CD tested and entered into the OFA registry, and that the parents and offspring have been DNA parentage certified (usually available through your national Kennel Club).

Cerebellar degeneration is not the most frequent genetic disorder affecting the breed, but is the oldest documented simple inherited disorder in Gordon Setters. With the availability of an accurate and inexpensive genetic test, no Gordon Setter, their owners or breeders should have to deal with the affected state of this disorder going forward.

(This article can be reprinted with permission from the author Jerold.bell@tufts.edu)

To order cheek swab kits by phone, call:
North Carolina State University Veterinary Genetics Laboratory
Phone-Voice Mail: 919.513.3314
Hours: Monday-Friday, 9 a.m. – 4 p.m.
Facility: NC State CVM Research Building

To order cheek swab kits via an e-mail at the following address:
vcgl@lists.ncsu.edu
Please state the following in your e-mail:
Your mailing address.
Number of kits you would like.
Type of test, (which breed), you are requesting,Gordon Setter, Cerebellar Degeneration.

Additional Links:  GSCA Health Survey 2004

(This article contains photos that are not intended nor do they relate to the content of the article.)

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