What is a common sign of poisoning in horses after consuming foxglove?

The consumption of foxglove by horses can lead to serious health issues primarily because it contains toxins known as cardiac glycosides, which can significantly affect heart function. Therefore, nausea and heart issues are common signs of poisoning when horses ingest this plant.

The presence of nausea may indicate distress in the gastrointestinal system, while the heart issues can manifest as arrhythmias or other cardiac dysfunctions due to the toxic compounds in foxglove interfering with normal heart rhythms. Such direct effects on heart health are key indicators of toxicity that warrant immediate veterinary attention.

Other signs of distress, such as agitation or restlessness, may occur as a secondary response to discomfort or pain, but they are not as directly correlated with the specific effects of foxglove poisoning as nausea and heart problems are. Similarly, a poor coat condition typically develops over time due to chronic conditions or deficiencies, rather than being an immediate reaction to toxic ingestion. Increased appetite is generally the opposite of what might be expected after ingesting a toxic substance, as horses often exhibit reduced appetite when they are unwell. Thus, the most accurate and relevant symptoms of foxglove poisoning are indeed nausea and heart issues.