Sensory Neuropathy DNA Testing for Border Collies

The Border collie is a popular dog breed in the UK and worldwide, renowned not only for their role as working herding dogs but also as intelligent and energetic companions excelling in canine sports. However, their unique genetics bring specific hereditary health concerns worth understanding, especially when it comes to responsible breeding and ownership.

One such hereditary condition is sensory neuropathy (SN), a neurological disorder causing progressive degeneration of the sensory and motor nerve cells. Fortunately, modern DNA testing offers a reliable way to detect whether a Border collie carries the mutation associated with SN, helping owners and breeders make informed decisions to reduce the risk of affected puppies.

What is sensory neuropathy in Border Collies?

Sensory neuropathy, often abbreviated as SN, is an inherited neurological disease affecting a small subset of Border collies. The condition typically manifests between 2 and 7 months of age, when the degeneration of sensory and motor nerve cells begins to impair the dog's coordination and sensation.

Symptoms of SN commonly include obsessive licking and chewing of the limbs due to numbness and discomfort, "knuckling" of the paws where dogs walk on their knuckles instead of their pads, progressive loss of coordination (ataxia), and overall diminished sensation in the limbs and tail. In advanced cases, affected dogs may experience incontinence and difficulties swallowing, often necessitating humane euthanasia for welfare reasons before the age of two years.

How is sensory neuropathy inherited in Border Collies?

SN follows an autosomal recessive pattern of inheritance. This means that a puppy will develop the condition only if it inherits two copies of the affected gene, one from each parent. Understanding the genetic status of both parent dogs is crucial for predicting the likelihood of SN in their litter. Here's a summary of inheritance scenarios:

• Two clear (non-carrier) parents will produce a clear litter free from SN.
• Two affected parents will produce a litter where all puppies are affected by SN.
• Two carrier parents produce a mix: approximately 25% affected, 50% carriers, and 25% clear puppies.
• A clear parent bred with an affected parent will produce all carrier puppies.
• A clear parent bred with a carrier produces approximately 50% clear and 50% carrier puppies.
• An affected parent bred with a carrier results in approximately 50% affected and 50% carrier puppies.

Recognising symptoms and effects of sensory neuropathy

Early detection of SN symptoms is vital. Concerned owners may observe early signs such as:

• Repeated licking or chewing of the feet or limbs.
• Knuckling or unusual walking patterns reflecting loss of paw sensation.
• Progressive loss of coordination, making walking difficult.
• Sensory deficits and reduced reaction to touch or pain stimuli.
• Later-stage issues like urinary incontinence and difficulty swallowing.

Unfortunately, there is currently no effective treatment or cure for sensory neuropathy. Management focuses on supportive care to maintain quality of life, while breeders play a key role in reducing disease incidence by using DNA testing to avoid breeding affected or carrier dogs together.

How to arrange DNA testing for sensory neuropathy in your Border Collie

In the UK, several reputable organisations offer DNA testing for SN. The Kennel Club provides an individual SN DNA test kit, as well as a comprehensive breed-specific genetic testing package for Border collies, covering multiple hereditary conditions including SN.

Testing involves collecting a simple mouth or cheek swab from your dog, which you can do at home with the provided kit or with your vet’s assistance. The sample is then sent to a laboratory for analysis, with results typically returned within 1-3 weeks.

Results classify your dog as clear (non-carrier), carrier, or affected. This information helps breeders make ethically responsible mating decisions and enables owners to prepare for managing their dog's health if necessary.

Breeding recommendations and responsible ownership

Responsible breeding is essential to reduce the incidence of sensory neuropathy. Breeders should:

• Test all breeding dogs for SN status before mating.
• Avoid breeding two carriers together as this risks producing affected puppies.
• Breach carriers only to clear dogs to maintain genetic diversity while minimising disease risk.
• Keep detailed health records and share information transparently amongst the breeding community.

Owners who are not breeding should still consider testing their pets to understand their genetic health and support welfare improvements within the breed.

Summary and key takeaways

In conclusion, sensory neuropathy is a serious inherited condition in Border collies. DNA testing empowers breeders and owners to reduce transmission risks through responsible breeding and informed care. If you own or plan to breed a Border collie, consider discussing SN DNA testing with your vet or a trustworthy breeder to protect your dog's health and wellbeing.