Prevention and treatment of equine atypical myopathy – an acute, highly fatal disease of unknown etiology.

This study focuses on equine atypical myopathy (AM), an acute and highly fatal disease with an unclear cause. The research attempts to articulate the current understanding of AM and strategies for its treatment and prevention based on known risk factors and past case analyses.

Understanding Equine Atypical Myopathy

• This fatal disease in horses, whos cause hasn’t been determined yet, lasts on average 72 hours and has a mortality rate of 85%.
• Hints suggest the cause of AM might be an ingested or internally produced toxin – like a bacterial toxin, mycotoxin, or phytotoxin.
• An understanding of the disease indicates that the degeneration of muscle tissues in AM is due to an interference in lipid metabolism that primarily targets type I myocytes.

Treatment Strategies

• Once a case of AM is suspected, intervention should center around providing anti-inflammatory relief, anti-oxidants, and intravenous fluids to correct potential electrolyte imbalances, most notably hypocalcemia.
• Even though selenium deficiencies are not always present in AM cases, implementing aggressive anti-oxidant therapy might be beneficial as horses deficient in this mineral may be at higher risk of contracting AM.
• One successfully treated case involved administering supplemental vitamin C, vitamin E, selenium and DMSO, together with intravenous fluids and anti-inflammatories.

Preventive Measures

• Grazing time reduction during adverse weather conditions in autumn and spring could curtail incidence rates, especially in horses under three years who are more vulnerable to AM.
• Providing additional feeds or a salt/mineral block, as well as regular vaccination and deworming might lower the chances of horses developing AM.
• Spreading manure on pastures, an activity associated with AM outbreaks, should be avoided during autumn and spring.
• Immediate removal of all horses from pastures where an AM case is suspected or confirmed can prevent potential spread.
• Monitoring serum creatine kinase (CK) levels in groupmates could serve as a tool to identify subclinical cases.

Future Research

• Further studies are necessary to ascertain whether administering carbohydrates can improve the survival rates of clinical cases of AM.
• Additional retrospective studies are needed to find out whether using specific treatments – such as giving certain anti-oxidants, or carbohydrate supplementation – affect the clinical outcome.
• The ongoing work of the Atypical Myopathy Alert Group (AMAG) at the Université de Liège will help document future outbreaks of AM and identify other risk factors.
• Once the exact cause of AM is identified, it will be possible to formulate targeted therapies, enabling early intervention for the disease.