Common Symptoms
Greyhound Polyneuropathy is an inherited progressive neurologic disorder affecting Greyhounds. Affected dogs typically present between three and nine months of age with exercise intolerance and an abnormal “bunny-hopping” gait. The symptoms progress to severe muscle wasting and Ataxia. Affected dogs may also have an abnormal sounding bark, be unable to bark, have noisy breathing and/or have difficulty breathing. In severe cases dogs can die from respiratory failure, but typically, affected dogs are humanely euthanized by one year of age.
Breed-Specific Information for the Greyhound
The Mutation of the NDRG1 gene associated with Greyhound Polyneuropathy has been identified in the Greyhound. Though the exact frequency in the overall Greyhound population is unknown, 25.3% out of 245 unrelated, healthy Greyhound show dogs were carriers of the mutation. When dogs with symptoms of the disease were included, 29.7% out of 283 Greyhound show dogs were carriers of the mutation and 3.5% had two copies of the mutation and were affected. Interestingly, none of the 112 Greyhound racing dogs had the causal disease mutation.
Testing Tips
Genetic testing of the NDRG1 gene in Greyhounds will reliably determine whether a dog is a genetic Carrier of Greyhound Polyneuropathy. Greyhound Polyneuropathy is inherited in an Autosomal Recessive manner in dogs meaning that they must receive two copies of the mutated gene (one from each parent) to develop the disease. In general, carrier dogs do not have features of the disease but when bred with another carrier of the same Mutation, there is a risk of having affected pups. Each pup that is born to this pairing has a 25% chance of inheriting the disease and a 50% chance of inheriting one copy and being a carrier of the NDRG1 gene mutation. Reliable genetic testing is important for determining breeding practices. In order to eliminate this mutation from breeding lines and to avoid the potential of producing affected pups, breeding of known carriers to each other is not recommended. Greyhounds that are not carriers of the mutation have no increased risk of having affected pups.
There may be other causes of this condition in dogs and a normal result does not exclude a different mutation in this gene or any other gene that may result in a similar genetic disease or trait.
References
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Drögemüller C, Becker D, Kessler B, Kemter E, Tetens J, Jurina K, Jäderlund KH, Flagstad A, Perloski M, Lindblad-Toh K, Matiasek K. A deletion in the N-myc downstream regulated gene 1 (NDRG1) gene in Greyhounds with polyneuropathy. PLoS One. 2010 Jun 22; 5(6):e11258.
[PubMed: 20582309]
