The type 1 neuropathy (LPN1) in Leonberger starts at the age of 2-4 year and shows a severe progression. The symptoms of this polyneuropathy include wobbly gait and paralysis especially from the backhand. Affected dogs are not able to stand up in the final stage of the disease. Breathing noises, strange barking voice and difficulties in swallowing are other typical symptoms. The causative mutation causes around 20% of all polyneuropathy cases in the Leonberger breed. Other aetiologic mutations exist.