Degenerative encephalopathy in the Nova Scotia Duck Tolling Retriever

Degenerative encephalopathy is a progressive neurological disease in which brain tissue, especially grey matter is gradually damaged. The disease can appear at a young age, approximately between 2 months and 5 years. Typical symptoms include involuntary movements during sleep, increased anxiety, hypersensitivity to noise, coordination disorders, and changes in gait. The neurological symptoms worsen over time and significantly affect the dog's quality of life.

The disease is caused by a missense mutation c.4507G>A in the RB1CC1 gene, which plays an important role in the regulation of autophagy, cell survival, and nerve cell stability.

The mutation is inherited in an autosomal recessive manner. It only manifests itself in individuals who have inherited the mutated allele from both parents (recessive homozygotes). Heterozygotes are individuals who have inherited the mutated allele from only one parent, show no symptoms of the disease, and are clinically healthy. However, they can pass the mutated allele on to their offspring. If two heterozygous individuals mate, theoretically 25% of their offspring will be completely healthy, 50% will be carriers, and 25% will inherit the mutated allele from both parents and will therefore be affected by the disease.

Genetic testing can clearly reveal an animal's genotype and is a useful tool for breeders to prevent the unintentional breeding of affected puppies.

.

References:

Guo, J., Bullock, G., O'Brien, D.P., Johnson, G.S., Katz, M.L. : An RB1CC1 missense variant in Nova Scotia Duck Tolling Retrievers with degenerative encephalopathy. Genes (Basel) 16:269, 2025. Pubmed reference: 40149422