Slow-Starting Stallion

We just started using a 3-year-old Quarter Horse stallion for breeding. He is sort of interested and will rub his head on the mare a bit, but he drops about half-way, then up, down, up, down. He doesn't seem shy or anxious, just lazy, like a gelding. Sometimes he'll just stand for a long time, even with his head in the mare's tail, or he'll ditz around with her tail like a foal does with its mom. He does eventually get ready and do the job, but you never know how long it will take! And sometimes he just pops up on her sideways without an erection. Sometimes when he has gotten a fairly good erection, he just rubs his chin on her rump and doesn't go up. When he has bred, he doesn't really get a complete erection until after he mounts.

Can medications help? When you have to stand in the breeding shed for an hour or more to breed a mare, it gets to be a bit much. I don't even want to think about trying to collect this horse! We have heard there is something like Viagra for horses. We've been working with him since just before Christmas, and it's now the first week in February. Before long his outside mares will be arriving, and the pressure will be on for real. Any input would be greatly appreciated.                  Anonymously Frustrated in the Midwest

While there are no silver bullet medications, some treatments can help boost a stallion's libido, and we certainly do recommend them when people get in a pinch with a slow-starting novice breeder under pressure to get going, or an older stallion that has diminished sexual arousal and response with his book of mares backing up. I'll get to them in a minute.

There are many more simple, inexpensive, and relatively risk-free management and handling steps that can be taken; in the end, these are often much more reliably effective in achieving the results you want.

First of all, for some stallions coming three years of actual age, the behavior you describe--lazy, lolly-gaggy, or playful--is a sign of immaturity and inexperience. Now, some experts would recommend just waiting a year or so to let this horse mature a bit. That might be a good solution for certain stallions, especially if their testicles have not matured. But for most 2 1/2- to 3-year-olds, sexual behavioral maturation can be nurtured along quite quickly when necessary. We would recommend, for example:

  • Plenty of everyday access to mares, even directly in a pasture if necessary, along a safe fence line, in a round pen "teasing box" within a pasture of mares, or in a barn with mares. It almost always helps to get those youngsters away from other stallions, who might have a suppressive effect on their behavioral and physiological maturation.
  • Patient, encouraging handling with minimal safe restraint around mares. It sounds like you have been doing that already.
  • Provide a variety of mares in good natural estrus, even with more than one in the shed at a time.
  • Have the stallion approach the mare's head, with the mare allowed to move a bit and posture normally, and to turn her head back in that solicitous posture.
  • Allow him to mount without an erection if he tries.
  • Avoid panic, and don't be too concerned until at least after Valentine's Day. It's interesting that you wrote in early February. In my experience with young novice breeders, the middle of February is the natural time for many to have their first maturation spurt in sexual behavior. Here in Pennsylvania, the first nice, warm, sunny, breezy day in mid-February will often coincide with the first signs of mature stallion-like behavior in colts. That is often on Valentine's Day or close to it. We certainly don't understand all the mechanisms, but it's a good date to remember, and postpone your worry. At the same time, it's good to do what you are doing and get things lined up in case you need to be more aggressive after that.

Other Tips and Tricks

In trying to boost a young breeder along, there are often many little tricks that are difficult to describe. For example, when a stallion is lolly-gagging at the tail, it can help to wiggle the mare a bit, or walk her very slowly a couple steps and stop quickly. That can be more exciting to a stallion than a completely motionless mare. Also, we sometimes fit the stallion with blinkers or a blindfold. For whatever reason, this appears to help some stallions focus and become aroused and proceed more efficiently. For some it does nothing, but little is lost in trying. Also, if your stallion really likes a particular mare, you can blanket her and collect urine or vaginal wipes and freeze them to save to "perfume" mares that appear less attractive to your fella.

Engage a wise, experienced stallion handler. When you get frustrated, you might find an old, wise stallion handler or someone who has started many stallions and feels confident and positive about the young guys. Having such an experienced stallion starter on site for a few sessions can often add a lot of useful tricks to your plan. For example, there are little tricks for when your colt seems ready, but won't mount, that can stimulate him to mount. These are best demonstrated by someone experienced with the technique.

Relax and get organized with a plan. It's easy to get frustrated and overestimate the time we spend with slow stallions. I once did an informal study of how long we actually spent vs. how long the owners and veterinarians thought they spent with breeding. I don't recall the details of the data now, but we always overestimate the time we spend when things aren't progressing. Some people get relief from the frustration if they schedule 45 minutes for such stallions, and focus on the time rather than the progress. In other words, I am going to stay here for 45 minutes, no matter what happens, and finish then no matter whether or not the stallion progressed. It's surprising how often the job is done in less than 30 minutes.


Now to the medications that we sometimes recommend in instances where the goal is to improve sexual arousal and response. One of the most common questions we get is about Viagra for horses. Actually, Viagra's mechanism of action is often misunderstood. It works by enhancing the vascular mechanics of erection, and has no direct effects on sexual arousal. Of course, in humans the hope of better "performance" can be a relief and can be exciting, so it indirectly enhances arousal. In stallions, there are only rare instances where the mechanical ability to achieve erection is the problem. And in those rare cases, we do have drugs that work on the mechanics of erection that have been well-tested in stallions.

In your horse's case, if he is interested, he can perform, so there is nothing wrong with the machinery, so to speak. The stallion version of Viagra would not help. But there are things that will work to boost libido and arousal.

Gonadotropin-releasing hormone (or GnRH), a neurohormone naturally found in the brain and involved in releasing pituitary hormones that in turn cause the testicle to release male hormones, can be used judiciously for good results in most stallions. Sometimes human chorionic gonadotropin (hCG) is used instead of GnRH to mimic a pituitary hormone that stimulates the testicle in the stallion to release androgens (male sex hormones). Or in a crisis, testosterone itself can be given, but this has to be done very carefully so as not to adversely affect the stallion's own endocrinology.

The GnRH and testosterone approaches have been studied in systematic controlled research in both normal and low-libido stallions, so we know that they are effective, and there are regimens that have been tested for safety. When there is time, baseline hormone studies can be done with your individual stallion to make more informed recommendations. This often improves the results.

It doesn't sound like your horse is anxious or intimidated, but for that type of slow-starting stallion, there are medications that can boost sexual response.

A Note of Caution

As an owner, when you reach for medications to improve sexual arousal, you need to be careful that the specific approach and recommendations you might be offered are based on good clinical veterinary research. It's best to consult with someone who has experience with the protocols or even the researchers who have developed the protocols. So often, much is lost in the translation from research to practice, and medications become inadvertently misapplied.

We are currently in a climate in both human and veterinary medicine where lots of things are given or taken without adequate knowledge of their safety and efficacy. Right now your youngster is slow to breed. You won't be pleased if two months from now his fertility has dropped due to adverse effects of a medication on his semen. For example, none of the herbal medications have been tested for efficacy, and these and other pharmacologic methods can have potential adverse effects on both behavior and fertility.

Many of the claims that various concoctions improve libido and fertility in men or stallions have either no or very shaky anecdotal evidence for effectiveness. The same is somewhat true with some popular hormone approaches that might seem legitimate because of mainstream veterinary acceptance. For many years now, unfortunately, we have been in a climate of the endocrine syndrome of the year, where every stallion or mare has low this or that and treatments are recommended. Sometimes nearly every valuable horse is treated for low this or that. There are several instances of inadequate critical research behind the endocrine diagnoses and interventions--for example, the number of horses and conditions tested for normal values is often minimal or of a special management condition. When we finally catch up with the research, it's found that levels that were diagnosed as low are clearly within the range of normal, healthy horses. Sometimes the recommendations might seem harmless, but not always. In some instances, proper diagnosis and therapy is unnecessarily delayed. Some of these things are even recommended to be given prophylactically to normal, fertile horses, or with the goal of boosting libido or fertility above normal. Yikes!

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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