In June 2000, Dr. Jerold Bell, DVM, and Dr. Alexander de Lahunta, PhD., DVM, examined a videotape of Murphy, my Scottie, who suffered for years with an undiagnosed movement disorder that affected his ability to walk normally. After considering Murphy’s history, both doctors agreed he had clinical symptoms of Cerebellar Abiotrophy (CA), a rare, slow-to-progress neurological disease that causes loss of coordination. Having experience with this disorder and after finding other CA affected Scotties; these doctors realized CA was a newly described disorder affecting the breed. Prior to that time, it wasn’t yet established that this disease existed in Scotties so their discovery was quite astounding.

CA causes ataxia or the “inability to coordinate voluntary muscular movements.” Some Scottie owners might have encountered this disorder over the years, no one can be certain. In 1995, the STCA HTF breed survey indicated the incidence of ataxia in Scotties was one affected out of every 200 dogs. It was therefore established Scotties had ataxia, but no cause was determined. In an effort find more CA affected Scotties, Carole Fry Owen, a well-known health advocate for the breed, published the article “Ataxia in Scotties: Wobbly Dogs” which appeared in The Bagpiper, the Scottie Scamper and on the STCA website. Many owners of “wobbly” Scotties responded to that article and have since received a clinical diagnosis of CA in their dogs. Recently, in August 2001, two veterinarians from South Africa published the first scientific study on CA in the Scottish Terrier, confirming the disease affects the breed, however, before that report was even published, Dr. Bell, Dr. de Lahunta and the STCA HTF were already at work on the problem!

Symptoms of CA include failure to control the rate, range, and force of a movement, exaggerated limb responses, such as goose-stepping or hopping and delayed and exaggerated postural responses, such as under or overshooting a food bowl when attempting to eat. Limb movements are spastic, clumsy, faltering, and jerky. Often a broad-based stance is present and swaying of the hips may be seen while walking. Symptoms are usually noticed between six months to one year of age and beyond and can be subtle at first; often an owner only suspects their Scottie is clumsy.

CA can be difficult to diagnose. The relative mildness of symptoms and its slow-progression can cause some to mistake CA for Scottie Cramp. Most dogs with Cramp appear normal and only exhibit symptoms occasionally. Signs of uncoordination associated with CA are always present once symptoms develop. Some Scotties have Patella luxation (slipping-kneecaps), which can also complicate diagnosis but that is another unrelated condition affecting one or both hind legs.

Dr. Bell is the Assistant Clinical Professor of Genetics at Tufts University School of Veterinary Medicine and is the national project administrator for numerous genetic disease control programs of purebred dogs. Once aware of CA in the Scottish Terrier, Dr. Bell explained the following: “As this disorder has not been “worked up” and reported in the breed, there are many owners, veterinarians, and neurologists out there that are not informed of its presence. An important first step and contribution to the breed is to document it”.

Dr. Bell contacted the STCA and submitted a proposal, offering to determine the genetic parameters of CA in the breed. In May 2001, less than one year after learning of CA in Scotties, the STCA HTF formally retained his services. In the short time Dr. Bell has been working on this project, he’s been able to confirm CA is hereditary in Scotties and caused by a defective autosomal recessive gene.

Autosomal recessive inheritance means both parents carry a defective gene that can be passed on to male or female offspring. If a dog inherits two copies of the defective gene, one from each parent, they will be affected. If only one copy is inherited a carrier is produced and if no defective gene is inherited, the dog remains clear. Because both parents of an affected dog are positively identified as carriers and repeat breedings would produce additional affected dogs, anyone having a Scottie diagnosed with CA should notify the breeder and owner of the sire who produced the dog.

Presently Dr. Bell is working to determine how widespread CA is the breed and his database grows with each Scottie diagnosed. He has made recommendations to the STCA HTF for collection and storage of blood samples from affected Scotties, and possibly their relatives, to insure DNA is available for future studies. Hopefully that will lead to the development of a test for carriers. Once a test is available, a breeder could determine if their dog carries the defective gene before they were bred.

Dr. Bell is currently available to any Scottie owner or breeder, worldwide, who might suspect their dog has CA or a neurological disease. Owners can contact him for a confidential consultation free of charge and he will assist with a clinical diagnosis. He will ask you to send him a videotape of your dog, including certain movements such as side views walking, trotting and running, front and back views and footage of the dog going up and down stairs. It's important to include pedigree information, a copy of AKC registration, or other registration information, if available, to help Dr. Bell determine the genetic spread of the gene responsible for CA in Scotties. As his database expands he hopes to be in a position to offer private pedigree analysis to breeders who wish to avoid producing CA. The development of a DNA test for carriers is the long-term goal for this ongoing project. Dr. Bell offers complete confidentiality, please contact him at: Dr. Jerold Bell, DVM, Veterinary Genetic Counseling, PO Box 3399, Enfield, CT 06083. E-mail: GENETICVET@AOL.COM

In addition, Dr. Alexander de Lahunta, Ph.D., DVM, a renowned veterinary neurologist and pathologist is working with Dr. Bell on this research in the Scottish Terrier, and will also accept and review a video of a possible CA affected dog. Since specific abnormalities of the brain are present in animals with CA, which can only be confirmed after death, an owner wanting an absolute definitive diagnosis can contact Dr. de Lahunta. He has offered to examine the brain of any Scottie suspected to have CA at no cost. Dr. de Lahunta, a Professor at Cornell College of Veterinary Medicine is currently teaching veterinary students about this newly described disorder in the Scottie, once in practice, they will be better equipped to diagnose CA in the Scottie and perhaps in other breeds as well. Please contact him at: Dr. Alexander de Lahunta, Ph.D., DVM, Dept. of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. E-mail: AD43@CORNELL.EDU

If a Scottie owner suspects their dog might have CA and is uncertain what the symptoms look like, a VHS videotape or DVD is available showing several Scotties at different stages of disease. This educational tool exists thanks to several owners of CA Scotties who felt that seeing actual footage of CA affected dogs could help explain the symptoms described in this disease. To request a copy of the videotape or DVD, please contact: Debbie Smith, 6556 Pinar Rd., Harborcreek, PA 16421, Ph# 814-899-2856, E-mail: LITLBLKDOG@AOL.COM

In August 2002, Dr. Bell reported that 20 Scotties were diagnosed with CA. He had reports of additional dogs with symptoms that sounded like CA and was awaiting videotape or follow-up on those dogs. He’s indicated the defective gene responsible for CA is very old and widespread throughout the breed. At least 6 ancestral lines trace back 7 or 8 generations and come together to produce an affected dog. The Scotties from South Africa trace back to English ancestors common to American dogs. At this time Dr. Bell says there is no particular “hotspot” of risk and pedigree analysis is still premature right now. Eventually, that will become available by Dr. Bell once more information is learned about CA in Scotties.

The STCA HTF has retained Dr. Bell for an additional year, September 2002 to August 2003. Please see The Bagpiper and the STCA website for any additional updates.

By Debbie Smith
STCA HTF
CA Project