Horses have been an integral part of human society for thousands of years. Many horse owners breed their best mares to continue good bloodlines and pass on desirable traits, and wean the foals at approximately six months of age. Getting a horse's milk to dry up can take some time, but a healthy mare and foal is worth the effort.
Separate your mare from her foal as soon as the foal is ready to wean. Most foals will continue to nurse for as long as the mare will let them, and nursing stimulates the mare to keep producing milk. Move the foal to his own pen where he cannot reach her teats to nurse.
Cut any high protein feed that your mare may be eating and transition your mare to a diet of clean hay only. High protein levels in the body encourage milk production, so halting any supplemental feeding as soon as you have started the weaning process will help her milk dry up faster.
Add powdered nettle to your mare's diet to dry her up. Nettle is a natural diuretic and will make milk production more difficult for your mare. Place a couple handfuls of sweet feed in her feed pan and sprinkle two tablespoons over the sweet feed every day until her milk dries up.
Fill her water trough with fresh, clean water to prevent her from becoming dehydrated. Weaning can be a difficult time for both mare and foal, and dirty or stagnant water will discourage your mare from drinking enough to keep her healthy.
Return your mare to a normal work routine as soon as possible. You can resume riding her and conditioning her for competition as soon as you have separated her from the foal. Working her gives your mare a task to concentrate on, and the exercise, in addition to resuming a normal feed routine, will help her milk dry up and her body return to normal.
Check with your vet if your mare's teats become inflamed or red during the weaning process. Any extreme swelling or redness can indicate mastitis, a very painful condition in which the teats block off and the milk cannot dry up. He will prescribe medication to help relieve her pain and allow her milk to dry up.
Don't place any other young horses with your mare during weaning. Even foals who were not birthed by your mare may attempt to nurse, which will only extend the time it takes her to dry up.