Medical Management of the Excitable Mare and Gelding

Cranky behavior can be associated with mares.  Pinning of ears, bucking, and kicking at stall walls can be a source of frustration and can interfere with the performance and enjoyment of your horse.
 
With all horses, you may be ready to go on a trail ride, enter a parade, go to a show, or need to lay your horse up due to injury.  You are worried your horse gets too excited on trail rides.  The balloons in the parade set her off.   Going around a course of fences she wants to run away.  Or, you just need to lay him up for a month of quiet resting of a tendon injury and after two days of stall rest, he is climbing the walls.   These are all instances where medical management of the excitable horse comes into play.
 
For Mares (and many geldings) using progesterone-type hormone therapy can eliminate cranky behavior and signs of being in heat and allow your horse to focus on their job.  It is interesting that both mares and geldings who are a little too hyper seem to respond.  For mares, the additional benefit is that these medications will keep them out of heat.  Many mares who are nice and wonderful most of the time become terrors when they come into heat.  Others who normally pay attention to you will suddenly squat and urinate when passing any other horse during a heat period.  Either way heat suppression is helpful. 
 
There are multiple methods of giving progesterone-like substances.  The method that most consistently produces the desired calming effect is the administration of an oral syrup of altrenogest.  The most familiar brand name is Regu-mate.  Giving it every day will in a short period of time result in the majority of horses calming down without losing any athletic ability. Altrenogest effectively suppresses heat in 95 percent of mares after 3 days of treatment. On the downside, it must be given every day in order to work, so diligence is required.
 
Other progesterone-like medications can also be effective but are less consistent in their results.  That means that there is more individual variation in response to their use. Medroxy-progesterone shots which are used as birth control in humans, are often tried.  There a various protocols, but most commonly it is given as an injection every 21 days.  It has advantage of this method is that the medication is given only every three weeks.  No other work needs to be done. 
 
Another choice is Progesterone in oil.  This is given via an in-the-muscle injection once a week. 
 
Yet another way to suppress heat behavior in mares is the implantation of a large, sterile glass ball or marble into the uterus. In one study 42% of mares having the implant placed in their uterus had a markedly prolonged period before their next heat cycle lasting up to 3 months.   This is a good alternative for owners who do not wish to use hormonal therapy on their mares.  That being said, slightly less than half the mares responded as desired.
 
The progesterone therapies appear to have a calming effect on geldings as well as mares.  At this time, they are not prohibited by USEF or California horse show medication rules.  Competition geldings and mares may have their performance enhanced by the ability to focus on their jobs instead of unwanted and cranky behavior.
 
Also allowable in the show ring is the use of a pheromone ointment.  Equine Appeasing Pheromone (EAP) works without any sedation and helps calm horses in order to deal with stressful situations. The pheromone is released by a mare’s udder to attract foals to the udder during the nursing period.
 
The kind of stressful situations that can be helped include stress caused by transportation, loading into a trailer, handling, arrival in new environments, and breaking. Also events like fireworks, parades, and care by a veterinarian or blacksmith. The introduction of a new exercise such as teaching a horse to school a Liverpool or jumping over or into water, and even trail riding can induce stress.
 
The pheromone comes as an ointment that is applied below the nostrils of your horse. Then your horse is placed in a quiet stall for 20 min. The effect will last for 2 to 2 ½ hours.
 
Elegant studies have been published from European centers demonstrating that the use of EAP decreased stress indicators and unwanted behavior when horses were being transported, when horses were learning a new skill, when highly reactive horses were clipped, when foals were separated from their mothers for weaning, and when horses were subjected to a test known to induce a fear reaction.
 
Individual horses respond to varying degrees.  Probably the clients who have felt the best response has been when used with ponies.
 
For horses too spooky on the trail or wound up after a few days in a stall, the first line of treatment is the administration of short-acting sedatives.  For the trail or parade horse that gets too excitable acepromazine is a good choice.  It can require up to half an hour or so to take effect and the effects last for a few hours.  The acepromazine dose can be adjusted so as to not get the horse so sedated that he stumbles like a drunk while providing sufficient calming effect that the deer or wild pig running through the woods will not set your horse bolting in the other direction or the horse that has been stall rested can be ridden without fear that any noise will set her off bucking.  Similarly, you can also administer a gel form of the sedative dermosedan under the tongue. Any form of sedative cannot be used for horses entered in competition because all governing bodies have labeled them as forbidden drugs.
 
Another case where calming is needed is in the laid-up horse.   A horse with a serious tendon or bone injury can be required to be kept in a stall for 2 or 3 months.  Many horses go bonkers confined for that long.   In these instances, it is often prudent to administer sedative drugs to minimize the agitation and prevent re-injury from rambunctious behavior.  Equine veterinarians have found that a human drug called Fluphenazine, can give long-acting sedative effects to a horse.  Administered once, the effects can last three to four weeks in some horses and at least an average of two weeks. Another drug, reserpine has been used and must be given daily.  Of course, acepromazine can be used in these situations.  Because its effects last only hours, acepromazine would need to be given multiple times each day in the laid-up horse to be effective.
 
In summary, there are many instances where medical management of the excitable horse is both reasonable and prudent.  In the excitable trail horse or parade horse oral administration of a drug like acepromazine or dermosedan may be the best choice.  In the show horse or mare with poor reaction to her heat cycles hormone therapy with a Progesterone like syrup or implant may provide the answer.  Other horses respond to pheromone therapy. In the laid-up horse, a longer-acting sedative can give you the calming effect you need.