Symptoms of Leukoencephalomyelopathy in affected dogs include: inability to control bodily movements, inability to judge distance, generalized muscle weakness, hypermetria, and exaggerated spinal reflexes. Neuronal examination revealed myelin breakdown, followed by swelling of the axons.
Due to the progressive derogative nature of the disorder, affected dogs are usually euthanized. Symptoms usually appear at animal’s young age.
Leukoencephalomyelopathy (LEMP) is caused by a mutation within the gene NAPEPLD. NAPEPLD (N-acyl phosphatidylethanolamine phospholipase D) gene encodes for an enzyme of the endocannabinoid system, important in myelin regulation. Population testing of 200 Rottweilers reveals a carrier rate of 8%.
The disorder is inherited in an autosomal recessive pattern. Healthy parents of an affected puppy are obligate heterozygotes, and therefore carry one mutant allele. Heterozygotes have no symptoms. Dogs homozygous for the mutation will display the symptoms of the LEMP. At conception, when mating two carrier dogs, each cub has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.