Samaras and seedlings of Acer pseudoplatanus are potential sources of hypoglycin A intoxication in atypical myopathy without necessarily inducing clinical signs.
BACKGROUND
Ingestion of sycamore seeds (Acer pseudoplatanus) is the likely source of hypoglycin A in atypical myopathy (AM) but ingestion of seedlings in spring might also contribute to intoxication.


OBJECTIVE
To test for hypoglycin A in seeds and seedlings collected on pastures where AM cases were reported and compare its concentration in serum of affected and healthy horses.


METHODS
Field investigation of clinical cases.


METHODS
Whenever present, samaras (the winged nuts that each contain one seed) and/or seedlings were collected from pastures of 8 AM cases and 5 unaffected horses from different premises. Two AM cases were each co-grazing with an apparently healthy horse. Acylcarnitines and hypoglycin A were quantified in blood samples of all horses involved in the study.


RESULTS
Hypoglycin A was detected in serum of AM (5.47 ± 1.60 μmol/l) but not in healthy controls pasturing where A. pseudoplatanus trees were not present. However, hypoglycin A was detected at high concentrations (7.98 μmol/l) in serum of a clinically healthy horse grazing a pasture with seedlings and samaras and also in the 2 healthy horses co-grazing with AM cases (0.43 ± 0.59 μmol/l). Hypoglycin A was detected in all samples of seeds and spring seedlings of A. pseudoplatanus.


CONCLUSIONS
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.
Department of Animal Productions: Biostatistics, Economy and Animal Selection, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
E
E
Baise
Department of Functional Sciences, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
J A
JA
Habyarimana
Equine Pole, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
H
H
Amory
Biochemical Genetics Laboratory, CHU Sart-Tilman, University of Liege, Belgium.
F
F
Boemer
Department of Food Sciences, Laboratory of Food Analysis, Fundamental and Applied Research for Animals and Health (FARAH) - Veterinary Public Health, University of Liège, Belgium.
C
C
Douny
Department of Functional Sciences, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
P
P
Gustin
Réseau d'EpidémioSurveillance en Pathologie Equine (RESPE), Caen, France.
C
C
Marcillaud-Pitel
Equine Pole, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
F
F
Patarin
Department of Functional Sciences, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
M
M
Weber
Equine Pole, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium.
D-M
DM
Votion
D031002:Acer / Q000737:chemistry*; D000818:Animals; D006734:Horse Diseases / Q000139:chemically induced*; D006736:Horses; D007005:Hypoglycins / Q000737:chemistry / Q000633:toxicity*; D009135:Muscular Diseases / Q000139:chemically induced / Q000662:veterinary*; D036226:Seedlings / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry
D007005:Hypoglycins; C041757:hypoglycin
Acer pseudoplatanus; atypical myopathy; horse; hypoglycin A; seasonal pasture myopathy; sycamore