Samaras and seedlings of Acer pseudoplatanus are potential sources of hypoglycin A intoxication in atypical myopathy without necessarily inducing clinical signs

Abstract

Atypical myopathy can be associated with the ingestion of sycamore samaras and also ingestion of seedlings. Hypoglycin A can be detected in the blood of horses with no detectable clinical signs at pasture in which there is A. pseudoplatanus. Determination of hypoglycin A concentration in blood is useful for screening for exposure in suspected cases of AM.

Equine atypical myopathy in the UK: Epidemiological characteristics of cases reported from 2011 to 2015 and factors associated with survival

“…Sycamore trees have been implicated in the disease as a source of HGA . In this study, 96% of respondents were aware of sycamore seeds within the affected pasture and a further 64% noticed the presence of sycamore seedlings.…”

Atypical myopathy: an update

“…However, in Europe, the source of hypoglycin A appears to be the seeds of A pseudoplatanus (Unger and others 2014) in the autumn, and its seedlings in the spring (Baise and others 2015). …”

Atypical myopathy – insights on pathogenesis

“…Indeed, in Baise et al . 's study the mean serum hypoglycin concentration was greater in cases of AM than healthy co‐grazers (mean 5.5 vs. 0.4 μ mol/l) and greater in non‐surviving cases than those that survived (mean 6.0 vs. 4.6 μ mol/l). Since the online publication of Baise et al .…”

“…As MCPA was not quantified in the work of Baise et al . , hypoglycin metabolism cannot be evaluated in the horse with high hypoglycin activity and no clinical signs. Magnesium, pyridoxal phosphate, thiamine and co‐enzyme A are all co‐factors in the metabolism of hypoglycin to MCPA ; therefore, availability of these compounds may modify the rate and extent of hypoglycin metabolism and hence an individual's susceptibility to disease.…”

“…The work of Baise and colleagues , in this issue of Equine Veterinary Journal, describes the serum hypoglycin concentration in horses with atypical myopathy (AM), co‐grazing horses and control horses on different pastures. Hypoglycin was detected in the serum of horses with AM, and at a much lower level in unaffected co‐grazing animals.…”