Acorns and all parts of the oak tree contain high levels of tannin, which is toxic if taken in sufficient quantities.

Some horses seem to almost become addicted to the acorns and will actively seek them out rather than graze - the greener the acorns the more attractive they seem.

Not all horses will eat them and a few acorns appear harmless, but in large amounts they will cause colic and depression, followed by dairrhoea in some cases, as the toxins build up. Liver failure and kidney damage can result, so please pick up your acorns or fence off the area.

Check your horse's dung for evidence of acorn ingestion.

Seek veterinary attention promptly as early treatment is more successful.