We still seem to have many more questions than answers concerning this Inherited Polyneuropathy. Some progress has been made in the research for a genetic marker; we now have twice as many "matches" on the X chromosome than we did at this time last year. In reality, this is like progressing from looking for a pin head in a hay stack to now looking for the proverbial needle. It remains a tremendous undertaking and the researchers, to date, have only been looking at one chromosome, the X. If it is found not to be associated with the X chromosome, or if it is found to affect more than one gene, then we are, very realistically, a very long way off from a blood test that will tell us who is a carrier.

With that in mind we are trying even harder to collect the necessary pieces of the puzzle to get as clear a picture as possible as to the mode of inheritance of this disease. At this time, there is some debate over the X-linked theory so the HREC is in the process of having a new pedigree analysis done as we now have nearly twice the number of dogs positively biopsied since the last analysis was made.

In the meantime, we continue to learn more about this disease. We thought it only caused clinical signs in males. Now, we know that it can affect the females as well, though in most cases it seems to affect them to a lesser degree. We had thought that affected dogs would show recognizable signs by the age of 3 or 4 years until a biopsy confirmed the diagnosis of a popular stud dog at the age of 9 years and other older dogs since him. We now know that this polyneuropathy can also be expressed in wide ranges of severity. It is this last fact that is most unnerving to me as I am afraid we are missing the diagnosis possibly quite frequently. There are still many veterinarians who are not familiar with the leonberger or ILP and they may erroneously assume the symptoms are of another more common cause.

Some dogs show only rear limb problems which vary from a mildly "sloppy" gait to a drunken-like pattern all the way to the classical high stepping "marionette-like" gait most of us associate with the disease. Some develop laryngeal paralysis (LP) later. Some develop LP first and the gait changes later.

The "nuts and bolts" to remember here, are that our Leonbergers' polyneuropathy shows its greatest affect on the longest nerves of the body, i.e., those in the rear limbs and the recurrent laryngeal nerve which travels from the spine, down the neck into the chest then loops back around and comes back up the neck to end at the muscles of the larynx. (If it was not caused by local trauma, then LP is the result of a polymyositis or, much more commonly, a neuropathy).

We need you owners and breeders to be vigilant for signs of genetic disease in your dogs. At this time, the lab is asking for blood samples from any affected dogs AND their relatives to proof a genetic marker once it is found. We also need nerve and muscle biopsies, both positive and negative, especially from any relatives of affected dogs, and from any dog showing possible symptoms.

To that end, the HREC is seeking the permission of owners who will allow us to publish the names of known affected (confirmed by biopsy) dogs. Please realize that, because of the uncertainties of how this condition is passed from one generation to the next, the list is fairly meaningless for use in breeding decisions.

Unfortunately, it is still hard to give advice on breeding decisions without a clear cut mode of inheritance. In general though, it would be better to use dogs that don't have any first degree affected relatives (parents, offspring, sibling, half siblings, etc) if possible. Unfortunately with some dogs first affected in the 6-10 year old age range, this is hard to truly determine. As to second degree relatives, it is hard to say at this point.