A wide epidemiological investigation on confirmed cases for atypical myopathy has been undertaken. This study enabled the identification of factors that tends to favour atypical myopathy. From these identified factors, some preventive measures can be proposed. Differences between countries in atypical myopathy-associated risk factors should exist since the flora, pasture characteristics and management of horses and pastures may differ markedly. Comparison of outbreaks within countries will be of value to narrow the common factors between affected areas. This will be of great help in our quest for the aetiological agents and strengthen our knowledge of epidemiology. This is the reason why we encourage horses owners and veterinarians confronted to a case to communicate us the information concerning a suspected cases by the use of the clinical questionnaire (to be filled in by the vet) and the epidemiological questionnaire (to be filled in by the owner of the horse).
Equine
Animals at risk
- Young horses less than 3 years old (especially horses of 18 months) are more frequently affected by atypical myopathy, but older horses may also be affected by the condition
- Horses in poor bodily condition are particularly at risk for atypical myopathy but atypical myopathy must not be considered as a disease concerning badly groomed horses!
- Not vaccinated, not dewormed horse
Prevention:
- Restrict access to pastures to young horses when clinical series of atypical myopathy occur
- Regular deworming and vaccination of horses
- Feed the horse enough for them to be in good body condition (however, obesity may not be recommended)
- Feed the horse concentrates during the at risk seasons (i.e. autumn and spring)
- The seasonal repartition of atypical myopathy suggests that the disease can be prevented by permanent stabling during the critical periods (i.e. autumn and spring) or at least, by reducing the time spent at pasture (a weather-dependent stabling should be considered in autumn and spring)
- Give supplementary feeding all year round
- Provide a salt block
- During the risky season, give drinking water coming from the distribution network and avoid giving access to humid areas for water
Risky pastures
- Once a case of atypical myopathy has been confirmed, the field should be banned for pasturing at least during autumn and spring. Prevention recommendations may only be broad and should target at reducing time spent at pasture during critical seasons
Pasture
Pasture at risk
- Pasture with a history of previous death(s) of horses
- Pasture with bare grassland
- Pastures where a stream/river flows across or around
- Pastures with accumulation of a lot of dead leaves
- supplementing hay during autumn increases the risk of atypical myopathy when it is given on the ground in a humid environment and/ or when it contains moulds
Preventive measures
- Removal of dead leaves
- Give only access to dry and lush pastures during the seasons at risk (i.e. autumn and spring)
- Remove any potential toxic plants and/or moulds
- Remove regularly the manure
- Reserve dry and fat pastures to young horses during the risky seasons