New Pathophysiological Insights from Serum Proteome Profiling in Equine Atypical Myopathy.

Equine atypical myopathy (AM) is a severe environmental intoxication linked to the ingestion of protoxins contained in seeds and seedlings of the sycamore maple () in Europe. The toxic metabolites cause a frequently fatal rhabdomyolysis syndrome in grazing horses. Since these toxic metabolites can also be present in cograzing horses, it is still unclear as to why, in a similar environmental context, some horses show signs of AM, whereas others remain clinically healthy.

In Vitro Assays for the Assessment of Impaired Mitochondrial Bioenergetics in Equine Atypical Myopathy.

Equine atypical myopathy is a seasonal intoxication of grazing equids. In Europe, this poisoning is associated with the ingestion of toxins contained in the seeds and seedlings of the sycamore maple (). The toxins involved in atypical myopathy are known to inhibit ß-oxidation of fatty acids and induce a general decrease in mitochondrial respiration, as determined by high-resolution respirometry applied to muscle samples taken from cases of atypical myopathy.

Atypical myopathy in 2 Bactrian camels.

Atypical myopathy (AM) is an acute seasonal rhabdomyolysis seen primarily in equids, caused by the ingestion of sycamore maple samaras containing hypoglycin A (HGA) and methylenecyclopropyl-glycine (MCPG). Toxic metabolites inhibit acyl-CoA dehydrogenases and enoyl-CoA hydratases, causing selective hyaline degeneration of type I muscle fibers. Two zoo-kept Bactrian camels () with a fatal course of AM had sudden onset of muscle pain and weakness, recumbency, and dysphagia, accompanied by increased serum creatine kinase activity and detection in serum of HGA, MCPG, and metabolites.

Potential new sources of hypoglycin A poisoning for equids kept at pasture in spring: a field pilot study.

Equine atypical myopathy in Europe results from hypoglycin A (HGA) exposure through the ingestion of samaras or seedlings of the sycamore maple tree. This pilot study aimed at better defining sources of HGA intoxication in spring. Samaras fallen on the ground and then seedlings were collected at two-week intervals from sycamore, Norway, and field maple trees over the spring 2016.

Mitochondrial function is altered in horse atypical myopathy.

Equine atypical myopathy in Europe is a fatal rhabdomyolysis syndrome that results from the ingestion of hypoglycin A contained in seeds and seedlings of Acer pseudoplatanus (sycamore maple). Acylcarnitine concentrations in serum and muscle OXPHOS capacity were determined in 15 atypical myopathy cases. All but one acylcarnitine were out of reference range and mitochondrial respiratory capacity was severely decreased up to 49% as compared to 10 healthy controls.

Determination of muscle mitochondrial respiratory capacity in Standardbred racehorses as an aid to predicting exertional rhabdomyolysis.

This prospective cohort study evaluated the potential of high-resolution respirometry applied to permeabilized muscle fibers for fitness evaluation in French Standardbred racehorses. Fitness evaluation by means of respirometric parameters did not correlate with racing performance registered over the following racing season. However, altered mitochondrial energy metabolism was associated with higher risk of developing exertional rhabdomyolysis, a common cause of exercise intolerance in racehorses.

Assessment of reactive oxygen species production in cultured equine skeletal myoblasts in response to conditions of anoxia followed by reoxygenation with or without exposure to peroxidases.

Objective: To culture equine myoblasts from muscle microbiopsy specimens, examine myoblast production of reactive oxygen species (ROS) in conditions of anoxia followed by reoxygenation, and assess the effects of horseradish peroxidase (HRP) and myeloperoxidase (MPO) on ROS production.

Animals: 5 healthy horses (5 to 15 years old).

Procedures: Equine skeletal myoblast cultures were derived from 1 or 2 microbiopsy specimens obtained from a triceps brachii muscle of each horse.

Atypical myopathy in grazing horses: a first exploratory data analysis.

Over the last decade, atypical myopathy (AM) in grazing horses has emerged in several European countries. An exploratory analysis was conducted to determine horse- and pasture-level indicators or factors associated with AM in Belgium. Belgian cases of AM confirmed by histology (n=57) were compared to their healthy co-grazing horses (n=77) and to pastured horses not involved with AM as controls (n=386).

Equine atypical myopathy: a review.

Atypical myopathy (AM) is an acute rhabdomyolysis syndrome that occurs at irregular intervals in grazing equines. An increasing number of outbreaks have been reported in recent years, including some from countries where the disease has not previously been diagnosed. In this review, clinical and other details of outbreaks of AM are analysed to better define its epidemiological profile.

History and clinical features of atypical myopathy in horses in Belgium (2000-2005).

Background: The emergent nature of atypical myopathy or atypical myoglobinuria (AM) necessitates precise description of its clinical and epidemiologic features.

Purpose: To define key features of AM to help practitioners recognize the disease and to advise owners to take preventive measures.

Animals: Belgian cases of AM confirmed by histology (CC horses; n = 57) from autumn 2000 to spring 2005 were included in the study.

Use of the impulse oscillometry system for testing pulmonary function during methacholine bronchoprovocation in horses.

Objective: To compare sensitivity of the impulse oscillometry system (IOS) with that of the conventional reference technique (CRT; ie, esophageal balloon method) for pulmonary function testing in horses.

Animals: 10 horses (4 healthy; 6 with recurrent airway obstruction [heaves] in remission).

Procedure: Healthy horses (group-A horses) and heaves-affected horses (group-B horses) were housed in a controlled environment.