Following on from this blog kindly sent to us by The Irish Japanese Spitz Association, here’s an update on Muscular Dystrophy in Japanese Spitz
A new genetic test for muscular dystrophy in the Japanese Spitz:
A minimally invasive genetic test using oral saliva swabs has now been developed in UCD. The new genetic test should assist us in identifying affected animals before clinical presentation and also permits carriers to be identified. It should therefore help eliminate the disease from future Japanese Spitz dogs.
Registration certificates, pedigrees and microchip numbers are collected with oral saliva swabs from Japanese Spitz dogs. Once saliva is collected, the DNA is extracted and PCR amplification of the DNA is carried out using specific primers for the mutation.So far a total of 64 Japanese Spitz dogs bred in Ireland have been tested. From those, three female carrier dogs were identified.
One adult male affected dog was also identified. The affected male is now 8 years old and has a milder disease than that seen in the seven dogs in the original study. However, there were some clinical signs present (hypersalivation, poor body condition score, stiffness on the hind limbs and muscle wastage) and a circulating muscle enzyme (creatine kinase) was elevated. He had several litters and one of his daughters is known to have inherited the mutant X chromosome and is therefore a carrier of the disease. One of his sons was also tested and was shown, as expected, not to carry the mutant chromosome.
The identification of this 8-year old affected dog indicates that the disease may also present in a milder form and confirms that breeding from such an animal can perpetuate the disease in the breed.
Conclusions:
The mutation for muscular dystrophy in the Japanese Spitz has been indentified and a genetic test has been designed at UCD.
Since no cure is available, prevention of this disease, by removing affected and carrier animals from the breeding population, is the best strategy for eliminating the disease from the breed. It is highly recommended that all dogs found to have passed on this trait, or to have been identified as affected or carriers by the genetic test, should be spayed or neutered to prevent its further transmission.
Authors:
Sabela Atencia DVM Resident in Small Animal Medicine
Catherine M Nolan, PhD, Senior Lecturer UCD School of Biology and Environmental Science
Dr. Carmel T Mooney MVB MPhil PhD DECVIM-CA MRCVS RCVS Specialist in Small Animal Medicine
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