Archives for Aug. 29, 2013

Degenerative myelopathy (DM) can be a devastating disease. Some breeds with this disease will lose the ability to walk in their later years – certainly after the age most dogs are bred. The mutation has been found in more than 70 breeds, which indicates that the original mutation might have occurred hundreds or thousands of years before many of the modern dog breeds emerged.

However, the frequency of the mutation varies between breeds and certainly the risk of developing the clinical disease seems quite distinct and breed-specific. For example, the frequency of carriers and homozygous mutation (affected) dogs in the Kerry blue terrier is about 52%(1), while carriers and affected dogs make up 91% of Pembroke Welsh corgis in Japan (2). Although wire fox terriers have a similar combined carrier and at-risk frequency of 90%, none have ever developed the clinical signs of DM (3).

In a 2001 study by Moore et al., German shepherd dogs had nearly twice the risk for death associated with spinal cord diseases, compared with Belgian shepherd dogs among military dogs (4). Although we don’t know for sure if the spinal cord disease was DM, certainly DM is one of the more common causes of this type of disorder ...

Neuronal Ceroid Lipofuscinosis (NCL) is a group of inherited mammalian diseases characterized by abnormal accumulations of a metabolic byproduct known as lipofuscin in nerve cells and various organs of the body.  The accumulation of lipofuscin eventually leads to progressive nerve cell dysfunction and severe neurological symptoms including behavioral changes, balance issues, muscle atrophy, uncoordinated movement, blindness, head tremors and seizures.  Other organ systems can also be affected to various degrees depending on the severity of lipofuscin build up.  Most dogs will die due the disease or are euthanized when neurologic problems progress to the point of preventing normal daily activities.  While most types of NCL begin to cause clinical signs around 1 to 2 years of age in dogs, the age of onset and speed of progression vary significantly upon the type of NCL.  Variable presentation and progression among NCL types is expected given that multiple genes can cause this clinical condition.

Unfortunately, details about disease incidence and prevalence within a breed are often difficult to obtain including NCL.  Without going into an in-depth discussion about statistics, among other conditions, in order to estimate incidence and prevalence of disease for an entire population, individuals ...