Common Symptoms
Juvenile laryngeal paralysis and polyneuropathy is an inherited, progressive neurological disease of black Russian terriers. Affected dogs present in the first few months of life with a variety of clinical signs associated with nervous system dysfunction including loud, raspy breathing on inspiration due to vocal cord paralysis, respiratory distress, hindlimb weakness, decreased or absent reflexes, loss of feeling in limbs, low muscle tone, and abnormal gait. In addition, affected dogs may also display persistent pupillary membranes, early-onset cataracts, aspiration pneumonia, and/or decreased GI motility. Due to the progressive nature of this disease, most affected dogs die or are humanely euthanized by six months of age.
Breed-Specific Information for the Black Russian Terrier
The Mutation of the RAB3GAP1 gene associated with juvenile laryngeal paralysis and polyneuropathy has been identified in black Russian terriers. Though the exact frequency in the overall black Russian terrier population is unknown, approximately 27% out of 249 black Russian terriers tested were carriers of the mutation.
Testing Tips
Genetic testing of the RAB3GAP1 gene in black Russian terriers will reliably determine whether a dog is a genetic Carrier of juvenile laryngeal paralysis and polyneuropathy. Juvenile laryngeal paralysis and 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 RAB3GAP1 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. Black Russian terriers 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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Mhlanga-Mutangaduraa T, Johnson GS, Schnabel RD, Taylor JF, Johnson GC, Katz ML , Shelton GD, Lever TE, Giulianog E, Granger N, Shomperg J, O’Brien DP. A mutation in the Warburg syndrome gene RAB3GAP1, causes a similar syndrome with polyneuropathy and neuronal vacuolation in Black Russian Terrier dogs. Neurobiol Dis. 2016 Feb;86:75-85. doi: 10.1016/j.nbd.2015.11.016.
[PubMed: 26607784]
