The research team at the University of Missouri College of Veterinary Medicine is looking for information from Chihuahua owners regarding a fatal neurodegenerative disease that may be present in your breed.
Dr Martin Katz, a member of the comparative neurology group here, is one of the world experts in a disease known as Neuronal Ceroid Lipofuscinosis, or NCL. The NCL's are a group of neurodegenerative diseases that are seen in a number of different breeds of dogs. Some of these are very similar to a condition known as Batten's Disease in humans. In the NCL's, there is storage material (basically, cell "garbage") that normally would be cleaned out from the cells of the nervous system (brain & retina, primarily), but instead it accumulates, or is stored, in the cell. This accumulation of "garbage" eventually kills the cell, and when enough cells are compromised, the affected individual loses function in the nervous system. There is no treatment for NCL, and the affected individual (dog or human) eventually dies from the effects of the disease.
Our research team has identified mutations responsible for NCL's in English Setters, American Bulldogs, Tibetan Terriers, Australian Shepherds, and Dachshunds (2 types, with different ages of onset). Recently we were contacted by researchers in another country who believe they have diagnosed NCL in 3 Chihuahuas. At present, we do not have access to pedigree information on these dogs to know what their background may be. We are very interested to know if any owners or breeders in the US or Canada may be aware of any Chihuahuas exhibiting progressive neurologic disease that could be NCL. In the cases reported, the age of onset of the first clinical signs was around 16 months of age, and death occurred by about 24 months of age. Clinical signs included visual impairment, behavioral changes (including anxiety), ataxia (inability to coordinate movement), and at the end stage, difficulty eating, and seizures.
If anyone is interested in information on NCL, information is available at www.CanineGeneticDiseases.net, and on the project list on the left side, click on NEURONAL CEROID LIPOFUSCINOSIS (NCL).
Animal Molecular Genetics Laboratory
University of Missouri - College of Veterinary Medicine
321 Connaway Hall
Columbia, MO 65211