A blood sample is the only way to definitively tell if your horse is anaemic but some of the clinical signs are:
• Decreased performance due to a lowered oxygen carrying ability.
• Poor recovery from exercise and excessive blowing
• Lack of stamina, poor finishing ability and general lethargy
• Swelling of lower legs and a rough dull coat,
• Pale mucous membranes may also be noticed such as the horse's gums appearing paler than usual.