Deaths of 16 horses linked to feed contamination as officials continue to investigate

State officials in Delaware, US, are investigating and working with the community after the reported deaths of 16 horses were connected to contaminated feed.

Vets in central Kent county reported neurological disease and deaths in horses at a number of properties, in four weeks in April and May.

The Delaware Department of Agriculture (DDA) released a statement last week (30 May) to notify horse owners of the issue.

“Many of the cases have been associated with feeding a corn-based feed,” the statement said. “Anyone using feed purchased in April is encouraged to contact their supplier to see if they are aware of any related concerns.

“Symptoms from equine cases were recorded by area veterinarians between 22 April and 17 May. The office of the state veterinarian and a local equine veterinarian submitted three samples of feed fed to affected horses for toxin analysis. All samples returned with levels of a fungal toxin called fumonisin. The levels in the samples significantly exceeded five parts per million (ppm), the maximum level recommended by FDA [the US Food and Drug Administration].”

Fumonisin is a toxin produced by mould that grows on corn; contamination levels vary and are affected by weather at harvesting time. Horses and rabbits are particularly sensitive to fumonisin, which can cause “softening” of the brain and neurological signs including a wobbly gait and progression to recumbency and death.

The samples submitted in this case had levels ranging from 31-101 ppm; a safe, quality feed should not have levels exceeding one ppm.

A spokesperson for the DDA told H&H the impact has been concentrated in the Amish community, and much of the information the department has gathered is second-hand, via vets and word of mouth.

“So we consider the number [of fatalities] an estimate and continue to interact with area vets and other stakeholders to gather information,” he said. “There have been no new reports of illness or fatalities since 17 May so, while we are still continuing to investigate, DDA is confident that the source was localised and that suspect product has been removed from commerce. There has been significant cooperation and communication within the community in response to this incident and DDA continues to work with the community, FDA and others to protect the health of horses and other livestock.

“The investigation is focused on preventing further impact from this incident but will also identify steps to be taken to prevent future issues.”

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