This is a disease where the spinal cord basically loses the insulation around the individual nerve fibres, reducing the transmission of electrical impulses up and down the spinal cord. The dog gets a non-painful, insidious, progressive weakness in the back legs. It’s a pretty sad disease because there is basically no treatment.
What breeds are affected ?
Mos frequently the german shepherd dog (2% of the breed) , but also the Welsh corgi (1.5%). It will rarely occur in other breeds and is very rare in cats.
What are the signs?
Progressive ataxia or wobbliness of the back legs, progressing to paresis or complete paralysis of the legs. Ultimately bladder incontinence over a 6-12 month period. Eventually they will have trouble swallowing.
What causes it?
it may be immune-related degeneration but essentially nobody knows. Degenerative changes have been identified throughout the spinal cord as well as portions of the brain, but lesions are most prominent in the thoracic spinal cord.
A group out of Missouri has proposed a major gene containing a mutation may predispose dogs to develop the disease and are working on genomic mapping to try to find it.
How is it diagnosed?
It is really based on classic clinical signs and excluding all other diseases. The definitive diagnosis would require a biopsy of the spinal cord, but that is a one-way kind of diagnostic test as it would irreparably damage the spinal cord.
Unfortunately there have been no effective treatments shown to alter to course of the disease. There are treatments that have been advised but not proven including vitamin E.
Physical therapy is important but physiotherapy is in its infancy in veterinary medicine.
The same group out of Missouri has started some trials looking at something called Antisense Oligonucleotide Therapy but this requires injection directly into the spinal space. Experimental work in rats has shown some promise.
A group in Melbourne has also reported on injecting mesenchymal stem cells into the spinal cord in two affected dogs, but the patients did not improve clinically.