A new non-invasive test for conditions relating to “tying-up” in horses has been pioneered in the US, with three mutations in the spotlight.
It means blood testing or a muscle biopsy is no longer required to test for mutations in three genes associated with Polysaccharide Storage Myopathy type 2 (PSSM2) and a mutation in one gene associated with Recurrent Exertional Rhabdomyolysis (RER). Instead, the test uses hairs from the horse’s tail.
German-based Center for Animal Genetics has signed an agreement with EquiSeq as the exclusive testing center for the Equine Myopathy Panel in Europe. Samples can be accepted from anywhere in the world. The test costs €238.
The mutations have been detected in affected horses of many breeds, including Quarter Horses, Thoroughbreds, Warmbloods, Arabians, Gaited Horses, Draft Horses, and many pony breeds. Affected horses often do not show symptoms until they have already been used for breeding or have had many years of investment in training.
EquiSeq’s Myopathy Panel, developed by researchers in New Mexico, USA, is the first commercial offering by the company, which is also researching additional genetic variants affecting horse health and performance.
Using genetic testing, owners and breeders can identify an affected horse before breeding or extensive training for sport. Veterinarians and other horse health professionals can make specific diagnoses and management plans. Although the diseases cannot be cured, a horse’s quality of life can be substantially improved with a correct diagnosis and the development of an appropriate management plan. Results will indicate if the horse is either normal (meaning it does not have any P-variants and cannot pass them on to offspring), affected — heterozygous (one copy of the P-variant and will pass it on 50% to offspring, who will have a 50% chance of developing PSSM2), or affected–homozygous, which means the horse has two copies of the P-variant and will pass it on to 100% of its offspring. All offspring will be at risk of developing PSSM2.
CAG’s Scientific Lead Melissa Cox said the diseases collectively known as PSSM2 are difficult to diagnose, because symptoms can vary in severity and age of onset.
“There are many horses and owners who will benefit from having correct, early diagnoses.”
Animal genetics testing and research company CAG specialises in horses, dogs, and cats. It was founded in 2014 by CeGaT, a human molecular genetics testing company, and Sportpferde, a sport horse breeder. CAG’s research program has also identified new mutations responsible for muscle diseases in dogs.