Polyneuropathy in Leonbergers is possibly the most actively researched neurological condition in dogs at the present time. This research is being led by Dr Diane Shelton of the Comparative Neuromuscular Laboratory at the University of California San Diego. Dr Shelton has studied PN in Leos since Harvey was brought to her attention in 1999.

The full scientific paper was published by Dr Shelton in April 2003. Inherited Polyneuropathy in Leonberger Dogs- A Mixed or Intermediate Form of Charcot-Marie-Tooth Disease?  requires, for the uninitiated, an understanding of genetics and a scientific mind, but the main thrust of the article is clear.

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There is much interest in finding a treatment for this condition. In late 2001 a small pilot Prosaptide™ study for canine idiopathic peripheral neuropathy with chronic axonal degeneration was undertaken and yielded encouraging results. Nine dogs were enrolled for six months of thrice weekly dosing. Briefly, the results were as follows:

Two dogs were dropped from the study. One died of unrelated causes and one dog owner was non-compliant.
Six of the 7 remaining dogs were still ambulatory at the end of 6 months dosing showing no signs of clinical worsening.
Five dogs showed clinical improvement with no degradation in neurological exams, nerve conduction velocities (NCVs) or nerve biopsies.
Three dogs were clinically improved and showed encouraging neurological exams post-trial.
Two dogs showed improved biopsies and/or improved sensory NCVs post-trial.
One dog showed evidence of nerve regeneration post-trial.

In 2002 the Myelos Corporation commenced a preliminary Pilot Study in Canine Axonal Degeneration. This is an 18-month clinical trial with a new experimental drug, Prosaptide TX14(A). Studies in rats, dogs and man with Prosaptide TX14(A) have yielded encouraging results for the treatment of Peripheral Neuropathy and Neuropathic Pain. Myelos are no longer enrolling dogs for the trial to confirm earlier positive findings. Initial results from the trial are expected towards the end of 2005. Click on the link below for more information.

 http://www.myelos.com/dogtrial/dogtrial.html

The current belief, supported by a substantial body of evidence, is that PN is inherited through a faulty gene on the X chromosome. PN occurs most often in males because females have two X chromosomes and males just the one. This means females can be carriers but may be affected if they are unlucky enough to have two faulty X chromosomes. The last pedigree analysis that was run showed that Harvey's Disease is 18 times more likely to be X linked recessive than autosomal recessive.

The search for the faulty gene is, therefore, vital. If you want to know more about how this is done, click on the link below:

http://cgap.ucdavis.edu/Guidelines.htm

It is critical to have information on full litters, biopsies at necropsy from all members of an affected litter are needed, whether they are clear or affected, and registered names of the affected dogs and their parents. You can trace a breed line through the Leonberger Database .

By now I hope that some of you at least will be thinking what do we do about this situation? It should not happen and, through responsible breeding strategies , it can virtually be eradicated.