As spring begins to arrive and then days begin to lengthen, many mares will begin to cycle again. If your mare’s behavior and focus change when she’s in heat, it can be a very large problem for show horses, trail horses, mares boarded and it can even be a danger to people as well. Thankfully there are some things that can be done to help if you are the unlucky owner or rider of one of these mares.
When we begin early spring, mares will enter what is called “transitional heat”. This is not a true heat cycle in that they will not produce follicles large enough to ovulate, but they will unfortunately show all of the behavior of heat or estrus. These periods may be very short in days or they may continue for much longer than a normal estrus cycle would last. Sometime around Mid-April, most mares will begin to cycle on a normal basis.
There are several things that can be done for the mare that has a history of undesirable behavior during her heat cycle. This is if you are not planning on breeding her this year. I will start with saying I have had several mares in the past that have had bad behavior during estrus and when they were allowed to have one foal, they never had an issue with the behavior again. That may be an option for some mares. If that is not an option for you, there are some things that can be used.
Progesterone will suppress the signs of estrus.
1. Regumate®(altrenogest)- This product is given orally and daily. It can be very expensive, it is messy to use, and woman should not come in direct contact with the product on their skin.
2. Altrenogest Bio-Release®- This is an injectable product that will work for 30 days. It works very well, but is expensive.
3. Other injectable Progesterone- There are other forms of injectable progesterone that can be given on a weekly basis. They are more cost effective, but can cause injection site soreness and inflammation.
4. Cattle Hormone Implants- This is an off label use of cattle implants. Some trainers are pleased with the results and they can last from 75-100 days depending on the time of year and the horse.
5. B-Goood- By Doctors Choice Supplements- This is an herbal product that produces progesterone. It works well in both mares and stallion acting geldings. It needs to be fed daily, but is fairly responable. This product will suppress the signs of estrus and produce an overall mellowing effect.
Other things that can be done
1. Surgically spay the Mare- The general rule is if the mare responds well to Regumate she would be a good candidate to be surgically spayed. This is permanent.
2. Placing a marble in the mare’s uterus- Over the last several years there has been the use of placing a marble into the mare’s uterus to mimic a pregnancy. This process doesn’t always work, can cause scar tissue in a mare that you may want to breed in the future and it can be difficult to remove the marble. Due to these reasons I personally do not suggest this practice.
As you can see there are several options to deal with the mare that becomes unruly or just plain unpleasant to be around during estrus. You can contact your veterinarian for further information on any of these products or procedures.