Sensory neuropathy is a progressive neurological disease affecting dogs. Affected dogs present between two and seven months of age with clinical signs including Ataxia, abnormal gait, muscle Atrophy, knuckling of the paws, and hyperextended limbs. Urinary incontinence and regurgitation may occur as the disease progresses. Affected dogs lose feeling in all limbs and develop an inability to recognize the position of their limbs in space. Hind limbs tend to be more severely affected than front limbs. Affected dogs will often chew on their lower limbs and feet as they lose feeling, resulting in severe wounds. Affected dogs are often euthanized within 18 months of diagnosis due to quality of life concerns.
Genetic testing of the FAM134B gene will reliably determine whether a dog is a genetic Carrier of sensory neuropathy. Sensory neuropathy 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 FAM134B 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. Dogs 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.
Forman OP, Hitti RJ, Pettitt L, Jenkins CA, O’Brien DP, Shelton GD, Risio LD, Quintana RG, Beltran E, Cathryn Mellersh. An inversion disrupting FAM134B is associated with sensory neuropathy in the Border Collie dog breed. G3 (Bethesda). 2016 Sep 8;6(9):2687-92.