La myoglobinurie atypique des équidés: une nouvelle maladie ?

History and Clinical Features of Atypical Myopathy in Horses in Belgium (2000–2005)

“…In addition, drastic weather conditions (especially wind) seem to predispose to the onset of clinical signs as has been suspected for a long time. 6,10,13,15,16 As triggering factors, drastic weather conditions might act as a stressor or be a prerequisite for the etiologic agent to be produced or to exert its toxicity. At the level of the animal, unfavorable weather (eg, cold temperatures and stormy weather) might cause stress and induce a metabolic imbalance.…”

“…No rhabdomyolysis-inducing plants were found in the pastures of CC horses or in those of previous reported cases of AM. 6,12,[14][15][16] On the other hand, as has frequently been reported in the literature, 10,14-16 the quality of the main vegetation found was questionable. For example, Ranunculus repens has no forage value and can be poisonous for livestock, 27 whereas the leaves and flowers of certain cyanogenic phenotypes of Trifolium repens contain a glycoside that may be potentially harmful for horses.…”

“…Biochemical and hematologic findings are consistent with those reported in the literature. [5][6][7]10,[12][13][14][15][16] The most remarkable biochemical changes were the increased activities of muscle serum enzyme activity, which indicated massive acute muscle damage. In CC horses, clinical signs were always associated with CK activity, largely .10,000 U/L but sometimes 100,000 to 1,000,000 U/L.…”

“…[10][11][12][13] In the fall of 1995, more than 100 horses died from the condition in Northern Germany, 14 and more recently, AM has been identified for the first time in Belgium 15 and France. 16 Lately, a review of cases of nonexertional rhabdomyolysis, which was previously attributed to tremetone toxicosis resulting from ingestion of white snakeroot plants, suggests that a seasonal myopathy similar to AM may also be present in the United States. 17 Indeed, tremetone was not detected in any of the samples collected from the reviewed cases, whereas the clinical, postmortem, and histologic findings in these horses were similar to those observed in AM, including the specific groups of muscles affected 6,10,14,15,18,19 and the marked accumulation of lipid in myofibers.…”

“…Because of the emergent nature of AM, a precise description of its clinical and epidemiologic features is essential to help practitioners recognize suspected cases. Several single episodes of AM have been reported in the literature, 6,[9][10][11][12][13][14][15][16] but large-scale studies are lacking. For that purpose, the data were collected from all Belgian cases of AM confirmed by histology since the first recognized Belgian outbreak in November 2000 15 until the end of the spring 2005.…”