Acquired multiple acyl-CoA dehydrogenase deficiency and marked selenium deficiency causing severe rhabdomyolysis in a horse.

This report describes a case of severe rhabdomyolysis in a pregnant mare associated with histopathologic and biochemical features of both selenium deficiency and acquired multiple acyl-CoA dehydrogenase deficiency (MADD) due to seasonal pasture myopathy (SPM). This case highlights the importance of assessing plasma selenium levels in horses with clinical signs of pasture myopathy as this deficiency may be a contributing or exacerbating factor.

Déficience multiple acquise de déshydrogénase acyl-CoA et carence en sélénium marquée causant une rhabdomyolyse grave chez un cheval. Ce rapport décrit le cas d'une rhabdomyolyse grave chez une jument gravide associée à des caractéristiques histopathologiques et biochimiques de la carence en sélénium et d'une carence multiple acquise de déhydrogénase acyl-CoA (MADD) causées par la myopathie saisonnière des pâturages (SPM). Ce cas souligne l'importance d'évaluer les niveaux de sélénium dans le plasma des chevaux manifestant des signes cliniques de myopathie du pâturage car cette carence peut être un facteur contributif ou aggravant.(Traduit par Isabelle Vallières).

Equine acquired multiple acyl-CoA dehydrogenase deficiency (MADD) in 14 horses associated with ingestion of Maple leaves (Acer pseudoplatanus) covered with European tar spot (Rhytisma acerinum).

This case-series describes fourteen horses suspected of equine acquired multiple acyl-CoA dehydrogenase deficiency (MADD) also known as atypical myopathy of which seven cases were confirmed biochemically with all horses having had access to leaves of the Maple tree (Acer pseudoplatanus) covered with European tar spot (Rhytisma acerinum). Assessment of organic acids, glycine conjugates, and acylcarnitines in urine was regarded as gold standard in the biochemical diagnosis of equine acquired multiple acyl-CoA dehydrogenase deficiency.

Persistent hypoglycemia associated with lipid storage myopathy in a paint foal.

A 12-hours-old Paint filly was examined because of weakness and dull mentation after birth. Despite IV administered dextrose, the foal remained persistently hypoglycemic with increase in serum activity of muscle and liver enzymes. A postmortem diagnosis of lipid myopathy most similar to multiple acyl-CoA dehydrogenase deficiency (MADD) was confirmed by findings of myofiber lipid accumulation, elevated urine organic acids, and serum free acylcarnitines with respect to control foals. This report details a case of equine neonatal lipid storage myopathy with many biochemical characteristics of MADD. Lipid storage myopathies should be included as a differential diagnosis in foals with persistent weakness and hypoglycemia.

Quantification of hypoglycin A as butyl ester.

L-α-amino-methylenecyclopropyl propionic acid (Hypoglycin A, HGA) has been found to be the toxic compound in fruits of the Sapindaceae family causing acute intoxication when ingested as food or feed. Clinical symptoms are consistent with acquired multiple acyl-CoA dehydrogenase deficiency (MADD). Ultra performance liquid chromatography-tandem mass spectrometry was used to measure HGA after butylation. Sample volumes were 10µL for serum and 20µL for urine. Internal standard for HGA was d3-leucine, samples were plotted on a 7-point linear calibration curve. Coefficients of variation were <15% at 0.01µmol HGA/L and ≤4.1% at 10µmol/L. R(2) values for linearity were ≥0.995. In order to quantify non-metabolized HGA together with some of its metabolites plus a spectrum of acyl glycines and acyl carnitines typical for acquired MADD in one single analysis HGA measurement was integrated into a method which we previously developed for metabolites of HGA and acyl conjugates. The new method is suitable for biochemical diagnosis of Ackee fruit poisoning or atypical myopathy in horses and for forensic purposes in cases of suspected HGA poisoning.

Equine multiple acyl-CoA dehydrogenase deficiency (MADD) associated with seasonal pasture myopathy in the midwestern United States.

BACKGROUND: Seasonal pasture myopathy (SPM) is a highly fatal form of nonexertional rhabdomyolysis that occurs in pastured horses in the United States during autumn or spring. In Europe, a similar condition, atypical myopathy (AM), is common. Recently, a defect of lipid metabolism, multiple acyl-CoA dehydrogenase deficiency (MADD), has been identified in horses with AM. OBJECTIVE: To determine if SPM in the United States is caused by MADD. ANIMALS: Six horses diagnosed with SPM based on history, clinical signs, and serum creatine kinase activity, or postmortem findings. METHODS: Retrospective descriptive study. Submissions to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were reviewed between April 2009 and January 2010 to identify cases of SPM. Inclusion criteria were pastured, presenting with acute nonexertional rhabdomyolysis, and serum, urine, or muscle samples available for analysis. Horses were evaluated for MADD by urine organic acids, serum acylcarnitines, muscle carnitine, or histopathology. RESULTS: Six horses had clinical signs and, where performed (4/6 horses), postmortem findings consistent with SPM. Affected muscle (4/4) showed degeneration with intramyofiber lipid accumulation, decreased free carnitine concentration, and increased carnitine esters. Serum acylcarnitine profiles (3/3) showed increases in short- and medium-chain acylcarnitines and urinary organic acid profiles (3/3) revealed increased ethylmalonic and methylsuccinic acid levels, and glycine conjugates, consistent with equine MADD. CONCLUSIONS AND CLINICAL IMPORTANCE: Similar to AM, the biochemical defect causing SPM is MADD, which causes defective muscular lipid metabolism and excessive myofiber lipid content. Diagnosis can be made by assessing serum acylcarnitine and urine organic acid profiles.