Foxtail is very commonly found in horse hay. Foxtail is a common meadow grass that has soft brush like flowering spikes. Unfortunately, it is hard to bale hay without getting foxtail mixed in as well. If you have a load of hay delivered to your farm that contains foxtail, it doesn’t mean the hay is bad, and your horse may never be bothered by it at all. However, many horses are irritated by the small spikes that come from the foxtail.
If you notice your horse not wanting to eat his hay or grain, check his gums and in between his teeth for ulcers or irritation. Sometimes their mouths will even bleed from the irritation or you may see the small foxtail spikes lodged in the gums. If you notice this, you may need to find another source of hay that does not contain the foxtail, and you should also consult with your veterinarian on how to treat the ulcers and inflammation.