Leonberger Polyneuropathy 1: Understanding and Testing LPN1

Leonberger Polyneuropathy 1 (LPN1) is a hereditary neurological disease affecting the Leonberger dog breed. This condition is part of a group of polyneuropathies impacting the dog’s neuromuscular system, leading to progressive nerve and muscle degeneration.

LPN1 primarily involves the breakdown of the myelin sheaths that insulate nerve fibres, interrupting communication between the brain and muscles. Symptoms usually arise between the ages of 2 and 4 years, with an average onset close to 2 years old.

Recognising Symptoms and Progression

Early signs often include exercise intolerance, a wobbly or abnormal gait starting in the hind limbs, and muscle weakness. As the disease progresses, muscle wasting intensifies, making movement difficult or impossible. Many affected dogs develop laryngeal paralysis, causing noisy breathing and changes in their bark. In severe cases, surgical intervention is required to alleviate breathing difficulties, and mobility may be lost entirely.

Genetics and Inheritance of LPN1

LPN1 is inherited in an autosomal recessive manner, meaning a dog must inherit two copies of the mutated gene (one from each parent) to develop the disease. Dogs are classified as:

• Clear: No copies of the mutated gene – will not develop or pass on the condition.
• Carrier: One copy of the mutated gene – generally healthy but can pass the gene to offspring.
• Affected: Two copies of the mutated gene – will develop LPN1.

Responsible breeders use genetic testing and the status information of potential breeding dogs to avoid producing affected puppies. For example, breeding two clear dogs guarantees clear litters, while breeding carriers requires careful consideration to prevent affected offspring.

Testing for Leonberger Polyneuropathy 1

Genetic testing for LPN1 is available through The Kennel Club’s approved laboratories in the UK. A veterinarian can collect a sample via a buccal swab or blood test and send it to be analysed. Results classify dogs as clear, carrier, or affected, which is then recorded in a breed database to guide responsible breeding.

Knowing your Leonberger puppy or dog’s status helps owners and breeders make informed decisions about health management and breeding practices.

Why Responsible Breeding Matters

LPN1 affects approximately 8-20% of polyneuropathy cases within the Leonberger breed, posing serious impacts on affected dogs' quality of life. By using genetic testing and avoiding breeding two carriers or affected dogs, the incidence of LPN1 can be significantly reduced over time.

This proactive approach promotes the health and welfare of Leonberger puppies born into the world, supporting the longevity and vitality of this beloved giant breed.

Summary

Leonberger Polyneuropathy 1 is a serious, inherited neurological disorder causing progressive nerve and muscle deterioration. It is irreversible but can be managed symptomatically. Genetic testing plays a crucial role in identifying carriers and affected individuals, enabling responsible breeding choices to reduce disease prevalence.

If you own a Leonberger or are considering bringing one into your family, arranging genetic testing and consulting experienced breeders will help ensure your dog’s health and happiness.