Our Kilroy had a severe case of Polyneuropathy that ultimately led to an early demise from Laryngeal Paralysis. This is a severe disease in some breeds of dogs including the Leonberger.

The Leonberger community has made the identification of genetic markers for this disease a priority.

Critical to understanding the disease is a general observation about genetics. All living beings have genetic traits that will express in some form or another. Some are as benign as hair or eye color and some include severe diseases.

When contemplating a companion animal we caution you to strongly consider the genetic issues for dogs in general and the specific issues for the breed you are considering. As you make this assessment, remember that ALL beings have different genetic anomalies.

Leonbergers are no exception.

What sets the Leonberger breeders apart is the dedication that they have to identifying the issues and planning breedings based on actionable data. All Leonberger Club of America breeders agree to abide by appropriate testing for hip, elbows, eyes, thyroid, and Polyneuropathy.

No breeding can possibly eliminate all genetic problems. The breeder must make conscientious and soundly considered decisions that will lessen the likelihood of undesirable traits.

Any breeder who tells you that his lines have no genetic problems is either not informed about good breeding practices or not sharing known data with you. What is critical is understanding that breeder’s approach to addressing any concerns.

There is exciting news for Leonberger Polyneuropathy!

For several years we have been fortunate enough to be able to test for one form of Polyneuropathy that is called LPN1. This has helped reduce the incidence of the disease. But it was not enough.

Researchers at the University of Minnesota and the University of Bern have identified a second genetic marker for another Polyneuropathy that is related to LPN1.

This different Polyneuropathy, LPN2, appears to have an onset at a later age and a different mode of transmission.

LPN1 is Autosomal Recessive requiring both parents to have at least one LPN1-D allele to produce affected puppies.

LPN2, the newly identified issue, is Autosomal Dominant, requiring only one parent to have an LPN2-D allele to produce affected puppies. The good news is that the carrier frequency is about 3 to 4 times lower than that of LPN1.


All dogs have genetic concerns. What is important is that Leonberger breeders are aware of the concerns and take steps to address it in breeding decisions.

Click on these links for detailed information about Leonberger Polyneuropathy and what these tests mean for the breed. Good information leads to good decisions.

Polyneuropathy information.