Equines

Thanks to the identified risk factors, preventive measures can be undertaken

Epidemiological studies (1,2,3) have revealed both risk and protective factors for atypical myopathy at the level of the horse. However, these factors were determined through statistical analysis and cannot on their own explain why some horses are affected by this disease while others are not.

The risk factors include:

• Young horses, especially those under 3 years old. This factor should be nuanced with the latest analyzed data; it should be noted that all age groups are represented among horses affected by atypical myopathy. Therefore, all horses are at risk, even though a higher number of affected horses are young. This observation may result from the fact that young horses are more often kept at pastures than older ones.
• Horses that remain at the pasture 24/7 throughout the year.
• Horses receiving hay in the autumn. Indeed, hay can contain samaras and seedlings that remain toxic even after several years. It is necessary to ensure that the distributed hay does not contain these harmful elements. Moreover, feeding hay on the ground or under a sycamore tree can increase the risk of samara or seedling ingestion.

Preventive measures, deduced from protective factors, include:

• Selecting pastures/areas with the least exposure to sycamore maples during risk periods.
• Preventing or limiting pasture access depending on weather conditions in the autumn and spring and/or limit access to the pasture < 6 hours per day.
• Providing additional feed (concentrated feeds) and a salt block throughout the year. First, feeding provides substrates such as carbohydrates that support energy metabolism. Second, the enzymes inhibited by the toxin require the action of a cofactor derived from riboflavin or vitamin B2. This vitamin can be found in alfalfa, for example. It is therefore also advisable to provide vitamins and minerals to horses preventively. Third, a well-fed equine will be less likely to ingest samaras or seedlings. Regarding hay, toxin-free forage can be distributed ad libitum above ground and away from sycamores.
• Providing water from the distribution network in a trough-type container and not allowing access to natural water sources.
• Ensuring the deworming and vaccination of your horses as advised by your veterinarian.