A mare's genitals are usually cleaned before breeding and foaling and during heat cycles. Udders can accumulate a waxy substance that needs to be cleaned off periodically. Udders should also be cleaned prior to foaling and occasionally during nursing.
Use a sheath-cleaning product, such as those used on geldings and stallions to remove any waxy accumulation from the udder. Apply the product to a cloth or sponge and wipe it gently on the area to be cleaned.
Loosen the dirt and waxy buildup by rubbing with the cloth or sponge or using your hands. Apply more of the sheath-cleaning product as needed.
Wipe away the loosened material with the cloth or sponge. Feel with your fingers for bits of dirt, grime or waxy buildup and pick them off.
Wash the udder using warm water and mild non-detergent soap and rinse it thoroughly. Pat dry with clean towels.
Wrap your mare's tail in a tail wrap to keep it out of the way.
Wash the genital area with warm water and a mild non-detergent soap. Use a soft sponge to wipe down the vulva and the hindquarters to either side. Rinse with warm water to remove the soap.
Clean the mare's vulva and adjacent hindquarters with Betadine wash or with a mild Betadine solution. Rinse with clean warm water and pat dry with clean towels.
If your mare is not used to having her udder cleaned, you may have to work up to it by first getting her accustomed to you handling her udder. Start by just touching and see how she reacts to that. Slide your hand down to the udder from up on her side. If you are washing a mare during her heat cycle you can skip the Betadine. Just use that when you are cleaning her before breeding or foaling.
Avoid getting kicked. Stand up close to the mare when working behind her. If she does kick, she only can give you a shove.