No doubt about it, mares can be moody — and with tremendous individual variation in how severely they are affected by their hormone levels. To determine whether or not a specific mare’s behavior pattern is hormone-related and/or could be treated by hormonal therapy you must accurately describe the problems and pinpoint them in her cycle.
Most people complain about what is really normal estrus behavior — winking, squirting urine, or backing up to other horses. A mare in estrus is far more interested in other horses than the humans in her environment. She may be easily distracted during work, especially if another horse is around. However, this behavior is usually amenable to proper training.
Just like a stallion who wants to yell to other horses (or worse) when he is being worked, the mare needs to be told in no uncertain terms that this is not the time nor place for that behavior. However, the drive to breed is, as it should be, extremely strong and mares can be more single-minded and determined than many stallions. This part of their education is often a job that can’t be undertaken by a novice horseman.
You also should not, and often can’t, attempt to control the signs of estrus when the mare is not being handled. Showing estrus is normal and healthy. Some mares show stronger estrus than others, but this does not mean there is anything wrong with the mare.
It is common for young fillies to show strong estrus periods, with shorter intervals between them, than older horses. In most cases, this is a normal adjustment/maturation period and will sort itself out in a year or so, with or without intervention. If you do “treat” these young fillies, don’t automatically resume treatment the following year. She may be fine at that time.
A more serious problem is the touchy or “bitchy” mare. These mares show varying degrees of hypersensitivity and may react quite violently with squealing, striking and kicking. The behavior may be limited to the first few days of estrus or can be present for much of the estrus cycle. When limited to a week or less, the touchiness is probably associated with some degree of ovarian pain or other reproductive system discomfort immediately prior to ovulation.
Mares that are difficult or dangerous to handle for most of their estrus cycle are either reacting to wide hormone swings, have hormonal imbalances and/or are just reflecting their intrinsic personality. In most cases, it is probably a combination of factors. However, even these mares will usually show some cycling in the severity of their behavior. It is important to keep a record of when the mare is at her worst, and her best, to attempt to determine if hormone levels are playing a role.
In addition to the behavior changes, some mares show other physical symptoms. Signs of discomfort described as acting colicky, back soreness, “kidney” soreness (really back soreness) or appearing to be tying-up have been described. This is likely related to the time of ovulation, with the source of the pain being increased ovarian activity.
A mare having these problems should be examined by an ultrasound of her ovaries and uterus to make sure these structures are normal. She should also receive a physical to rule out other causes. If she checks out normally, these symptoms can usually be easily controlled as needed by a dose or two of Banamine.
We believe Banamine is a simpler, less costly and more healthy approach than putting the mare on daily hormone therapy, such as Regumate. Like ibuprofen, nonsteroidal anti-inflammatories are most effective if started a day or so in advance of the anticipated painful time, so try to keep an accurate record of when the mare usually experiences these problems and treat accordingly.
Note: It is fairly well documented that fillies and mares have more problems with repeated tying-up than geldings. If you have a filly or mare with this problem, do not automatically assume hormonal therapy is the answer. The first step is to document true tying-up by having her blood analyzed for elevated muscle enzyme levels. Pay careful attention to when she is tying-up during her cycle. If it is during estrus, hormones like Regumate may help. However, if she is tying-up in midcycle, when progesterone is already high, you won’t be helping by loading her higher yet with the hormone that is already at its natural peak during that time.
To Regumate Or Not To Regumate
Regumate is the most widely used drug in controlling mare behavior. Regumate is a progesterone. Like progesterone birth-control pills or implants, it suppresses estrus by tricking the brain into thinking the mare is pregnant.
Regumate fans often say it makes the mare feel “content” — their reasoning being that pregnant mares feel “content.” We believe a pregnant mare more likely feels like a pregnant woman — so if your mare could talk, she would probably tell you she feels bloated, fat, sluggish, fatigued and sleepy.
Regumate will eliminate behavioral signs of estrus and may help with many physical problems that surface around ovulation. It may help even out the disposition of mares just generally out of sorts, touchy and difficult to work with throughout the cycle because of wide hormone swings or hormonal imbalances. However, we believe the “calming” effect is more a depression of sorts, and high-performance mares will often show reduced willingness, speed and brilliance as a result.
On the other hand, some mares respond to Regumate by the expected suppression of estrus behavior (winking, urinating) but a definite worsening of their personalities, becoming more irritable, touchy and even overly aggressive.
Long-term affects of Regumate are largely unknown. Certainly mares have been withdrawn from Regumate and successfully bred. What we don’t know is how many have not or if it takes longer to establish normal cycles and conception rates after long-term Regumate use.
Regumate also poses a hazard for women handling the drug and giving it to the mare. Menstrual irregularities can result if it is handled carelessly, and wearing gloves is advisable.
Nutritional therapy is a viable option with difficult mares. We’ve had success with some mares showing predominantly signs of nervousness and irritability using a blend of magnesium (3 to 5 grams), vitamin B6 (300 to 500 mg) and B1 (500 to 750 mg), which is also helpful for mares who tie up.
Of course, many herbal ingredients are believed to also alleviate moody-mare problems. As our chart on page 9 shows, a variety of herbals are available for problem mares. Look for ingredients you believe most relate to your mare’s problems and then experiment. Palatability is as much an issue as ingredients.
Although rarely done, spaying the mare (surgical removal of the ovaries) will definitely solve hormone-related behavior problems. Spaying normally involves the expense and risk of major abdominal surgery and, of course, will make her sterile. It may be the solution of choice for some mares and could turn out to be less expensive than a lifetime of costly hormonal therapy.
If difficulty concentrating during estrus is your major complaint, consider professional training. Likewise, aggressive mares may respond to different handling without hormone therapy. If you want to eliminate what is really normal behavior — winking, squirting during estrus — Regumate will certainly do it.
Regumate may be necessary for the real problem mares that are unpredictable, have wide mood swings and exhibit excessively strong estrus periods, although we would consider herbal preparations first, particularly if this is a high-performance mare. Every mare is an individual, and the precise nature of any hormonal abnormalities will determine how well the horse responds to a particular herbal or pharmaceutical.
We would first reach for products that con tain black cohosh and vitex agnus castus — the herbals known to contain phytoestrogens. However, experimentation is key. You must find the herbal ingredient your mare responds to and the product she finds palatable. Otherwise, you should seriously ask yourself if a gelding might not be a better choice for you.
Also With This Article
Click here to view ”Testosterone In Mares.”
Click here to view ”Case Histories.”
Click here to view ”Botanical Options For Problem Mares.”
Click here to view ”How Herbal Ingredients May Affect Your Mare.”
Click here to view ”The Basics: Heat And Hormones.”