Developing Breed-Specific Tests for Neurodegenerative Diseases in Dogs

There are very few things as frightening as seeing the health of your beloved dog disintegrate before your eyes while your veterinarian struggles to figure out the cause of her decline. Unfortunately, many canine diseases are currently difficult, or impossible to diagnose, let alone treat. One such group of diseases is the neuronal ceroid lipofuscinoses (NCLs.)

This family of inherited lysosomal storage diseases isn’t only a problem in dogs. Humans and canines can both suffer from the progressive nervous system damage these conditions cause, leading to symptoms that include vision loss, memory difficulties, seizures, problems with movement, and, eventually, death.

Although eight genes have been linked to development of human NCL, until recently only four of those genes had been associated with canine varieties of the disease. In 2010, however, scientists from the University of Missouri identified a novel form of NCL in a young miniature dachshund, and linked it to a fifth gene – the same gene responsible for the most common infant-onset form of NCL in humans - CLN1.

This research is an exciting development – not just for dog owners, but for human families that have been devastated by their own experience with NCLs. The timing and nature of NCL symptoms are dependant both on which gene is involved and how it is damaged. Therefore, as doctors and scientists identify and investigate a wider range of NCLs in dogs, they gain powerful new insights into both canine and human forms of the disease.

Related research has already created new hope for four dog breeds known to be affected by NCLs – English Setters, American Bulldogs, Border Collies, and Dachshunds. Scientists have been able to identify the genetic defects responsible for NCLs in each of these breeds and develop tests to detect the genes responsible. These tests will hopefully allow breeders to stamp out these devastating diseases in future generations, by removing the dogs that are most at risk from the breeding pool.

The work is far from over. Fortunately, ongoing support from the AKC Canine Health Foundation continues to help scientists in their quest to reduce the impact of NCLs on domestic dogs. It’s not an easy task. The causes of NCLs vary from breed to breed and the discovery process can be a long one.

Right now, the Missouri research group is actively working to identify the genes responsible for confirmed NCLs in Tibetan Terriers and Polish Lowland Sheepdogs in order to develop tests for those breeds. They are also hunting for affected Australian Shepherds in order to confirm their tentative identification of the mutation responsible for NCL in the breed. These scientists have one final goal – to confirm the reports of potential NCLs they are receiving from breed clubs in order to determine what other types of domestic dogs may be at risk. In order to do that, they need your help.

According to Professor Katz, a leader of the canine NCL studies at the University of Missouri, "It is only through the assistance of dog owners, breeders, and their veterinarians that we are able to identify the presence of NCL in a breed and subsequently identify the genetic basis and develop a DNA test that will identify affected dogs, carriers, and dogs that are free of the mutation." That’s why if you have, or care for, a dog experiencing a progressive decline of neurological functions such as vision, coordination, and/or cognitive function, Prof. Katz asks that you contact his research group. When your beloved pet is sick it can be hard to think of the bigger picture, but you may one day find some comfort in knowing that your dog’s contribution has helped to protect others of his breed.

This work was funded by AKC Canine Health Foundation Grant 732.

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