Polyneuropathy means "many abnormalities of the nervous system". The condition is generally characterized by a lack of coordination and instability that leads to a laboured gait. Many nervous system disorders that affect both dogs and people are inheritable.

In dogs, the breed most affected has been the Alaskan Malamute but cases have been discovered in the Leonberger….although the percentage of Leonbergers estimated to be carrying the affected gene is thought to be very small.

Measures have been taken by some breeders to prevent breeding from affected dogs, and therefore this will hopefully eradicate the rogue gene from the Leonberger family in the future.