The old family mare, who taught you to ride when you were too young to remember, but is now past her energetic best, may well be ready to have a baby of her own. But take a long pause before you ring up the nearest stud. This should be the first question you ask yourself. Your mare must be alert, happy, and eating up well, with a good coat and muscle tone. She must be neither too fat nor too thin.
Bad condition is one of the main reasons why mares fail to become pregnant.
Many mares are put in foal after they become unsound for riding through injury or a similar problem. But make sure you have resolved any injuries as far as possible. Your mare should not be on any painkiller dose, however small. Pregnancy is as hard on a mare's body as it is on a human's body, and any injuries will take far more strain than they do normally. The University of Wisconsin publishes a more detailed list of considerations in an article on breeding soundness in mares .