Definition

DM is the gradual and progressive loss of hind limb function, usually occurring in dogs of any breed over the age of 8 years. It is an inherited disease.

Symptoms

An affected dog begins to drag a hind limb, wearing away the toenails. As the problem progresses, gait becomes uncoordinated and the dog often stumbles when cornering. The gradual paralysis spreads to involve the forelimbs and may eventually lead to faecal incontinence.

Mode of Inheritance

The University of Missouri has isolated the gene responsible for DM and its mode of inheritance works in much the same way as CEA and MDR1, in that a dog inheriting two mutant or defective genes (one from each parent) will be affected by DM in old age to a greater or lesser extent.
For anyone interested www.laboklin.co.uk offers a genetic test for DM, using buccal swabs, at a cost of £76.00. As this is not a KC official scheme no results are ever published.

The Way Forward

If some of your ‘oldies’ have a tendency for their back-ends to collapse in old age, then it might be worth considering breeding away from the problem by using lines clear of the problem.

References:
http://en.wikipedia.org/wiki/canine_degenerative_myelopathy
http://www.veterinary-neurologist.co.uk/degenerative-myelopathy.htm
www.laboklin.co.uk
http://www.cvm.missouri.edu/neurology/dm/index.html
http://www.caninegeneticdiseases.net/DM/mainDM/htm

 Pat Hutchinson, Feb 2012
Health Coordinator, EACA