Multi-drug Resistance Gene Mutation - A Common Occurrence In Collies
Gribbles Veterinary have recently studied the multi-drug resistance gene (MDR1 gene) in collie dogs. The function of the MDR1 gene is to prevent dangerous drugs from entering the cerebral spinal fluid and negatively affecting the brain. Should the MDR1 gene be mutated the blood brain barrier is altered and hence transportation of drugs such as ivermectin is impinged.
The MDR1 gene also plays a major part in eliminating drugs from the body. When the gene is mutated drugs are not disposed of from the body as rapidly and hence a high plasma drug level ensues, as well as an increased chance of toxicity.
The antiparasitic drug ivermectin is not the only drug which has an effect on dogs with a mutated MDR1 gene. Various tranquilizers and anticancer drugs also cause problems in dogs with this mutation. When dogs with a mutated MDR1 gene are exposed to the aforementioned drugs they display severe neurological signs such as hyper salivation, tremor, ataxia, respiratory distress and in extreme cases, death.
DNA testing is a highly accurate method of checking whether or not your dog has a mutated MDR1 gene. Gribbles have devised a method of DNA testing which specifically targets the gene and can therefore be easily identified as normal or mutated. This is done from a simple cheek swab or blood test.
Some trivia: 75% of Australian collies are affected by this gene mutation.
Primary:
Ÿ Gribbles Veterinary, 2006, Detecting Multi-drug Sensitivities in Dogs (MDR1 Gene Test), viewed 29/5/2007, http://www.gribblesvets.com.au/info/general/Document/get/140/documentId/
Secondary:
Ÿ Nzymes.com (Division of Biopet), 2005, Special Alert: MDR1 Gene Mutation, viewed 29/5/2007, http://www.nzymes.com/Articles/MDR1_gene_mutation.htm
