Dog Polyneuropathy in Leonbergers: Genetic Welfare Crisis

Leonberger polyneuropathy is a severe hereditary neurological disease affecting a significant proportion of the breed, causing progressive paralysis and requiring urgent breeding reform.

Key Facts

Leonberger polyneuropathy (LEMP) affects an estimated 3% of Leonbergers, with carrier frequency much higher
The disease is caused by mutations in the ARHGEF10 or GJA9 genes, with multiple forms identified
Onset typically occurs between 1 and 9 years of age with progressive hindlimb weakness
Severely affected dogs often lose the ability to walk and require euthanasia
DNA tests are commercially available for known LEMP mutations, enabling screening before breeding

Welfare Considerations

LEMP causes progressive and ultimately fatal neurological decline in affected Leonbergers. Dogs experience worsening weakness, loss of proprioception (limb position sense), and ultimately inability to walk, stand, or maintain bladder control. The progressive nature of the disease means months to years of declining welfare before euthanasia becomes necessary. The existence of genetic tests for known LEMP mutations means that responsible breeders can eliminate the disease from their lines over time. The welfare cost of failing to test is paid entirely by affected dogs.

What You Can Do

Require DNA test certificates for LEMP mutations from Leonberger breeders before purchasing a puppy
Support kennel club policies requiring LEMP screening before registration
Advocate for breed clubs to actively promote and enforce genetic health testing
Donate to neurological research organisations working to identify all LEMP-causing mutations