10. You shouldn't vaccinate your stallion during breeding season--the vaccine may adversely affect sperm.
Busted! Although old-time vaccines used to make a horse sick and feverish for a day or 2 (which we already know can adversely affect sperm), equine vaccines available today generally don't cause these problems.
However, stress definitely has a negative effect on all bodily functions, including reproductive processes-and giving your stallion multiple vaccines on the same day could be stressful for him. And, even when the injection is given properly, once in a while the injection site will get swollen, hot, sore, and stiff for a day or 2 afterward. The resultant discomfort can interfere with your stallion's libido, as well as his ability to tease, mount, and ejaculate.
To reduce the risk of vaccination-related stress, follow these tips:
- Choose your stallion's vaccines wisely, in conjunction with your vet's advice. That is, don't just vaccinate your stallion willy-nilly for every disease ever discovered.
- Acquire vaccines from a reputable source, so you know they've been properly stored. If stored improperly, they can become spoiled or contaminated, or otherwise rendered ineffective.
- If possible, have your vet give all injections to ensure they're done properly and given in the right location.
- Use (or have your vet use) only preloaded, single-dose syringes, rather than vaccine drawn from a multiple-dose vial, as they're less likely to be contaminated.
- Give (or have your vet give) your stallion only one or two injections per day; wait at least a week before giving any more.
- Schedule each injection to take place during a time when your stallion won't be doing any breeding for a couple days to allow time for any swelling or soreness to go away.
11. Stallions are more susceptible to parasites than mares and geldings are.
Busted! Just being a stallion doesn't make for increased susceptibility. However, if your stallion is asked to work harder than he can handle during a busy breeding season, he can get stressed. Such stress can lower his immune system, making him vulnerable to parasite infestation (and other illnesses).
12. It takes 7 days to build a sperm cell.
Busted! From start to finish, the process of building a viable sperm cell takes 57 days! But it's a constant, ongoing process. At any one time, there are generations of sperm at various developmental stages in your stallion's testicles.
13. It's not normal for your stallion to masturbate, so you should take steps to stop him if he does--it'll affect his sperm count.
Busted! Wild stallions, as well as stallions in confinement, will drop their penises, become fully erected, and "masturbate" (move the penis upwards towards the belly) as often as every 3 hours, if left undisturbed. But they rarely ejaculate--so the sperm count isn't adversely affected. And, contrary to popular belief, a stallion that does this isn't necessarily more potent or fertile; this is just normal behavior that goes with the territory of being a stallion.
14. A stallion's testicles descend into his scrotum around the time he reaches puberty.
Busted! In most colts, full descent has taken place before birth, or within 10 days after birth. There are cases in which descent occurs as late as 2 to 3 years of age, but that's the exception, rather than the rule.
Idaho-based Karen E.N. Hayes, DVM, MS, is an equine-reproduction specialist. She and her psychologist husband, Dan Hayes, raise Friesian horses, using mostly shipped semen selected from the handful of approved stallions in the United States and Holland. "We joke with Darrell, our UPS man, that all our 'kids' are named after him," she says, referring to the frequent deliveries. "You know, Katrina Darrell, Olivia Darrell, Jacob Darrell, Zachariah Darrell, Ysibel Darrell, Darrell Darrell, etc."
This article first appeared in the January 2001 issue of Horse & Rider magazine.
