An hereditary form of polyneuropathy, termed Leonberger polyneuropathy type 1 (LPN1), was genetically characterized in 2010 by the Universities of Minnesota, Bern, and California-San Diego, and a genetic test developed.

The LPN1 test identifies dogs that have a severe disease with an age of onset less than 4 yr of age (mean = 2 yr). The LPN1 mutation is most likely inherited in an autosomal recessive manner. In other

words, a dog must have two copies of the LPN1 mutation (i.e., a LPN1-DD genotype) to develop this form of disease, which explains approximately 20% of all diagnosed cases of polyneuropathy in Leonbergers.

LPN2 appears to explain approximately 25% of all diagnosed polyneuropathy cases; so, along with LPN1 we now have genetic tests that account for almost 50% of all diagnosed cases of polyneuropathy in this breed.

LPN2 is a dominant condition, so a dog need have only a single copy of the LPN2 mutation (i.e., a LPN2-DN or a LPN2-DD genotype)to develop polyneuropathy. This has serious implications for breeders, as half of all offspring from a LPN2-DN dog will inherit a mutant D allele and thus be genetically-susceptible to LPN2.

For full explanations and testing see:

http://www.genetics.unibe.ch/unibe/vetmed/genetic/content/e2885/e3121/e3233/files3234/LPN2_eng_2014Jul01_eng.pdf

LEMP in Leonbergers:

A neurological disorder, termed leukoencephalomyelopathy (LEMP) has described in Rottweiler and Leonberger dogs.

Full details may be found here: https://www.vetmed.umn.edu/departments/veterinary-and-biomedical-sciences/research/canine-genetics-lab/genetic-testing/leonberger-polyneuropathy

For Test Results please refer to individual dogs / kennels