Horses on pasture may be affected by equine motor neuron disease.

The research article focuses on equine motor neuron disease (EMND) found in three horses that were fed on lush, grass-based pasture, an occurrence contrasting from North American findings where a lack of or limited access to green herbage is identified as a major risk factor for EMND.

Objective and Methods

• The primary objective of this research was to investigate if horses that are getting a seemingly sufficient intake of pasture herbage, which should meet their normal vitamin E requirements, can still develop EMND.
• The research methodology involved a questionnaire filled out by the owners of 32 European horses, all of which were diagnosed with EMND. The questionnaire inquired about various potential risk factors for EMND, which included factors intrinsic to the horses, management-related factors, nutritional factors, and environmental factors. It also sought information about symptoms, treatments, and the outcomes of each case.
• Along with the questionnaire, serum/plasma vitamin E data for these horses were also supplied by the veterinarians. It’s important to note that no control group was used in this study.

Results

• The results of the study showed that thirteen out of the 32 horses, or the ‘grazing’ group, had part-time or full-time access to grass-based pasture when EMND was first noticed. More specifically, some horses were grazing for at least 235 hours per day at the onset of EMND. Interestingly, despite grazing, the vitamin E status of all these horses was low.
• The remaining 19 horses were matched to cases reported in North America where the horses had limited or no access to green herbage.

Conclusions

• The study concludes that EMND cannot be dismissed just because a horse has access, even full-time, to lush, grass-based pasture.
• Furthermore, it suggests that insufficient vitamin E intake was unlikely the sole cause for either the low vitamin E status or the occurrence of EMND in the grazing horses. The researchers theorize that this might be due to aberrant bioavailability or exaggerated utilisation of vitamin E.