Degenerative myelopathy: current state of knowledge. Literatura review

Abstract

Canine Degenerative myelopathy (DM) is a late-onset neurodegenerative, first diagnosed in German Shepherd, but affects multiple dog breeds. DM manifests as a spinal disorder in adult dogs, insidious onset and slowly progressive course.

Many studies considered the possible etiology of DM unable to clarify the causes. Recent researches have identified as a likely cause a mutation of the SOD1 gene encoding superoxide dismutase 1 (SOD1), which also implies DM is a potential ortholog of Amyotrophic Lateral Sclerosis (ALS) of the human being.

The distribution of lesions and the clinical progression of MD are similar to those reported for certain types of ALS, with an onset characterized by upper motor neuron signs, with predominant lesions in the spinal thoracic region, with progression to lower motor neuron signs that become evident in the later stages of the disease.

Before establishing a clear equivalence between DM and ALS must explain some differences between two diseases. For example, in DM the axonopathy is diffuse (not restricted to lateral funiculus, as in ALS) and involves both sensory tracts as motors. Furthermore, except isolated communications, no evidence of neuronal damage in the brain or brain stem has been demonstrated.

Meanwhile, the dogs affected by DM are potential animal models for ALS, which can be used to probe the underlying processes of motor neuron degeneration, to map the modifier loci and identify the environmental factors which influence the severity of the disease.