Scientists seek Pomeranian dogs to participate in new gene study

University of Adelaide researchers are seeking Pomeranian dogs to participate in a new study to help identify how widespread a defective gene is in the breed's Australian population.

Veterinarians and scientists from the School of Animal and Veterinary Sciences are investigating methaemoglobinemia (MHb), a disorder that causes the blood to carry less oxygen around the body than normal. It causes a blue tongue and reduced exercise ability in Pomeranians, but may pose more serious complications for a dog under anaesthesia.

A free and simple mouth swab from a Pomeranian or PomX will provide enough DNA for researchers to perform a DNA test to check for the genetic variant.

"Our project aims to discover whether or not the defective gene is widespread in the Australian population of Pomeranian dogs. We are recruiting Pomeranian dog breeders and owners to provide cheek swab samples for DNA, " says project lead Associate Professor Anne Peaston

Associate Professor Peaston says veterinarians recently diagnosed a mild form of congenital methaemoglobinemia in an adult Pomeranian dog.

"Our index case was detected because her blue tongue turned almost black under stress. Genetic investigation showed that the dog indeed had a mutant CYB5R3 gene, and had inherited identical defective gene alleles from both parents," she says.

The same genetic defect has been reported in a family of Pomeranian dogs in Japan, indicating that this could be an international problem in the breed. 

Associate Professor Peaston says the gene variant may be carried silently by a dog.

"The low oxygen supply to the body caused by MHb is variable, and dogs may appear normal, or have relatively mild signs, such as tiring rapidly with exercise, excitement or stress, and development of a blue-brown tinge to the tongue. These can sometimes be overlooked by veterinarians and pose a problem for general anaesthesia."

"Our initial findings suggest that the MHb variant may be more widespread in the Australian Pomeranian breed than the single case confirmed so far. By participating in this study, your dog‘s results will help us to determine the prevalence of the variant gene within the wider breed population."

If researchers find that the CYB5R3 mutation is common in Pomeranian dogs in Australia, the results will assist the development of a DNA test to detect carriers of the variant gene and potentially restrict their participation in the breeding population to help eliminate the gene.

"In addition, information on the carrier status of dogs may be valuable information for veterinarians if general anaesthesia is required for any reason during treatment,"

"The gene's elimination would greatly benefit the welfare of this delightful little dog breed," says Associate Professor Peaston.

Tagged in Research, Engagement and Industry, School of Animal and Veterinary Sciences, Veterinary Medicine, Biomedical Science