Equine atypical myopathy: A review (original) (raw)
Related papers
An epidemiological study of myopathies in Warmblood horses
Equine Veterinary Journal, 2010
Reasons for performing study: There are few detailed reports describing muscular disorders in Warmblood horses.Objectives: To determine the types of muscular disorders that occur in Warmblood horses, along with presenting clinical signs, associated risk factors and response to diet and exercise recommendations, and to compare these characteristics between horses diagnosed with polysaccharide storage myopathy (PSSM), those diagnosed with a neuromuscular disorder other than PSSM (non-PSSM) and control horses.Methods: Subject details, muscle biopsy diagnosis and clinical history were compiled for Warmblood horses identified from records of biopsy submissions to the University of Minnesota Neuromuscular Diagnostic Laboratory. A standardised questionnaire was answered by owners at least 6 months after receiving the muscle biopsy report for an affected and a control horse.Results: Polysaccharide storage myopathy (72/132 horses) was the most common myopathy identified followed by recurrent exertional rhabdomyolysis (RER) (7/132), neurogenic or myogenic atrophy (7/132), and nonspecific myopathic changes (14/132). Thirty-two biopsies were normal. Gait abnormality, ‘tying-up’, Shivers, muscle fasciculations and atrophy were common presenting clinical signs. Forty-five owners completed questionnaires. There were no differences in sex, age, breed, history or management between control, PSSM and non-PSSM horses. Owners that provided the recommended low starch fat supplemented diet and regular daily exercise reported improvement in clinical signs in 68% (19/28) of horses with a biopsy submission and 71% of horses diagnosed with PSSM (15/21).Conclusions: Muscle biopsy evaluation was a valuable tool to identify a variety of myopathies in Warmblood breeds including PSSM and RER. These myopathies often presented as gait abnormalities or overt exertional rhabdomyolysis and both a low starch fat supplemented diet and regular exercise appeared to be important in their successful management.Potential relevance: Warmbloods are affected by a variety of muscle disorders, which, following muscle biopsy diagnosis can be improved through changes in diet and exercise regimes.
Atypical myopathy in grazing horses: A first exploratory data analysis
Veterinary Journal, 2009
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). The pastures where confirmed cases were grazing (42 pastures; 38 sites; 44 incidences of AM) were compared with those of the controls (216 pastures; 96 sites; no incidence of AM).
Veterinární Medicína
Objective of the study was to assess histopathological changes in horses with a clinical history of exertional rhabdomyolysis (ER) with special reference to polysaccharide storage myopathy and to compare histopathological findings in horses with and without a clinical history of ER. In total 39 muscle samples were collected, from horses with a history of repeated episodes of exertional rhabdomyolysis (test group, 10 horses) and from horses without clinical signs of muscular disorders in their history (control group, 29 horses). Frozen muscle samples were stained with haematoxylin and eosin and periodic acid-Schiff with and without amylase digestion. Histopathologic changes (amylase resistant polysaccharide, subsarcolemmal glycogen, intracytoplasmic masses, subsarcolemmal vacuoles, fibre size variation and internal nuclei) were evaluated. There was a statistically significant difference between groups in the presence of subsarcolemmal amylase sensitive glycogen deposits (P ≤ 0.0001),...
Equine Veterinary Journal, 2012
Reasons for performing study: Improved understanding of the epidemiology of atypical myopathy (AM) will help to define the environmental factors that permit or support the causal agent(s) to exert toxicity. Objectives: This European survey of AM aimed to describe spatiotemporal distribution, survival, clinical signs, circumstances in which AM develops and its different expressions between countries and over time. Methods: The spatiotemporal distribution, history and clinical features of AM cases reported to the Atypical Myopathy Alert Group from 2006 to 2009 were described. Comparisons of data from the most severely affected countries and from the large outbreaks were made with Fisher's exact and Welch's tests with Bonferroni correction. Results: Of 600 suspected cases, 354 met the diagnostic criteria for confirmed or highly probable AM. The largest outbreaks occurred during the autumns of 2006 and 2009 in Belgium, France and Germany. For the first time, donkeys, zebras and old horses were affected, and clinical signs such as gastrointestinal impaction, diarrhoea, penile prolapse, buccal ulceration and renal dysfunction were observed. Affected horses spent >6 h/day on pastures that almost always contained or were surrounded by trees. The latency period was estimated at up to 4 days. Overall survival rate was 26%. Although differences between countries in affected breeds, body condition, horse management and pasture characteristics were recognised, the common presenting clinical signs and mortality were similar between countries. Conclusions and potential relevance: This study describes new data on case details, history and clinical course of AM that is of preventive, diagnostic and therapeutic value. However, the true impact of the findings of this study on the development of or severity of AM should be tested with case-control studies.
Histochemical Changes of Skeletal Muscle in Equine Acute Rhabdomyolysis
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Veterinary Medicine, 2009
In two mixed breed horses that died due to acute rhabdomyolysis, were realized histopathology and histochemical exams. There were examined the following muscles: mean gluteus, semitendinosus and semimembranosus. Histopathology exam revealed some specific lesions for acute rhabdomyolysis, such as interfibrillar edema, granular and vacuolar degeneration and Zenker myofiber necrosis. Histochemical exam noticed in affected myofibers normal glycogen and amylase-resistant polysaccharide complex. Myofibers lesions degree was more severe in muscle cells that were enriched in PAS positive amylase-resistant polysaccharide material. A certain cause of acute rhabdomyolysis in both horses was polysaccharide storage myopathy in which the muscular presence of amylase-resistant polysaccharide complex is the pathognomonic finding.
Four cases of equine polysaccharide storage myopathy in the United Kingdom
2003
This paper describes four cases of equine polysaccharide storage myopathy which were confirmed by histological examination of muscle biopsy specimens. The horses were of mixed breeding, with warmblood and thoroughbred dominating. They all had recurrent episodes of rhabdomyolysis, indicated by clinical signs and increased plasma levels of muscle enzymes. They were managed conservatively and have continued athletic careers despite their
Journal of Equine Veterinary Science, 2014
Although creatine kinase (CK), aspartate transaminase (AST), cytokines, and oxidative stress parameters were shown to be useful biomarkers for diagnosis of equine rhabdomyolysis, additional biomarkers of the disease may be of interest to indicate prognosis of the disease. Therefore, the present study investigated acute phase proteins and trace elements as additional biomarkers of ER. Sixty male horses (4-6 years old) of 2 equal groups were used. Horses of the first group were clinically healthy and served as a control group, whereas horses of the second group were ER-diseased animals. Harvested sera were used for estimation of the activities of CK, AST, lactate dehydrogenase (LDH), serum amyloid A (SAA), haptoglobin (Hp), ceruloplasmin (Cp), copper, iron, and zinc, whereas plasma samples were used for determination of fibrinogen. The present findings revealed a significant (P .05) increase in values of CK, AST, and LDH in diseased horses compared to those in control values. In addition, a significant (P .05) increase in SAA (162.6 AE 5.32 mg/L), Hp (3.6 AE 0.54 g/L), Cp (39.32 AE 2.31 mg/L), and copper (28.36 AE 1.23 mmol/L) along with a significant (P .05) reduction in levels of iron (9.32 AE 0.23 mmol/L) and zinc (8.65 AE 1.02 mmol/L) was recorded in diseased horses compare to that in controls (11.3 AE 2.2 mg/L, 0.8 AE 0.2 g/L, 24.23 AE 1.32 mg/L, 18.41 AE 1.03 mmol/L, and 14.2 AE 0.42 mmol/L, respectively). In conclusion, SAA, Hp, Cp, copper, and zinc were useful prognostic biomarkers for the diagnosis of ER in Arabian horses.