A rise in deadly equine atypical myopathy (AM) cases has prompted the British Equine Veterinary Association (BEVA) to urge vets to be vigilant this spring.
Horses that develop AM are usually kept on sparse pastures, near trees from Acer pleudoplatanus (sycamore) or Acer negundo (box elder) that shed seeds containing the toxin hypoglycin A.
With more than five times as many cases of AM last autumn than in 2013, experts have warned vets to be alert in coming months as the disease occurs more frequently in spring.
Prognosis of the disease is poor, with a survival rate of less than 25%. Clinical symptoms of AM include muscle weakness or stiffness, colic-like symptoms, dark red-brown urine, recumbency and laboured breathing.
Preventive advice for horse owners includes:
- check spring pasture carefully for seeds prior to turnout
- provide supplementary feeding in the field to reduce the risk of horses ingesting the seeds
- fence off affected areas
Pastures without sycamore trees are still at risk as areas can still contain seeds spread by winds or flood water.
Celia Marr – partner at Rossdales Veterinary Surgeons in Newmarket, european specialist in equine internal medicine and editor of the Equine Veterinary Journal – said: “New collaborative research instigated last year between the University of Lige, the Irish Equine Centre and the Animal Health Trust should shed more light on the characteristics of the disease in this country. Once we know more about the specific causes we should be able to make more positive progress with prevention strategies.”
BEVA has provided free online access to the following two articles from the Equine Veterinary Education journal on the disease for all vets:
- Van Galen G and Votion D-M (2013). Management of cases suffering from atypical myopathy: interpretations of descriptive, epidemiological and pathophysiological findings (part one), Equine Veterinary Education 25(5): 264-270 (2013).
- Management of cases suffering from atypical myopathy: interpretations of descriptive, epidemiological and pathophysiological findings (part two), Equine Veterinary Education 25(6): 308-314.