CNN: When asked if that amount of sediment is a common finding during a necropsy, Dr. Gabriele Landolt, an assistant professor of equine medicine at Colorado State University’s veterinary college, said, “No, that is a lot. That should not be in the colon.” After the deaths of the two horses, stool samples collected from 25 of the unit’s horses showed that 80% of the tested horses had “moderate to high levels of sediment in their stool,” according to the report.

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