Questions & Answers from Dr. Rahal

The following questions come from actual clients.  If you have a horse question that you'd like answered, please email Dr. Rahal at at DesertHillsAnimalClinic@hotmail.com

1)     Do horses ever give birth to twins? OR triplets?  - I was sitting in the office with a stack of phone messages to return, mostly information questions.  This was before the days of “Google search”, so we got a lot of question/information-seeking calls. 

     One message stuck out and really intrigued me……”owner needs information about her twin foals”.  Unbelievable.  You see a mare’s uterus is really only big enough for one baby. Almost invariably when a mare twins, or has multiple embryos, the embryos spontaneously abort early to mid-gestation.  There just isn’t enough room in a mare’s womb to provide enough nutrition for 2 babies.  One baby will get “starved out” and die, which causes the other baby to abort, even though it was healthy.  This happens too early for the bigger foal to survive. It’s just too premature. 

     Occasionally the starved fetus will become “mummified”, meaning the embryo died and the mare’s body was able to ‘wall it off’ and prevent any dead tissue toxins from hurting the other fetus or causing abortion.  Usually those foals are born early, premature, because the mummy still took up some room, and the mummified fetus is delivered last and truthfully kind of scary and freakish looking.

     While I was preparing to call this client back, all the horrible problems were running through my mind that may be occurring with a mother trying to raise two foals:  a) failure of passive transfer (getting enough of that first milk or colostrum), b) dummy (comes when delivery takes too long and the foal is deprived of oxygen during birth, c) mare refusing one of the babies (by instinct they only ‘know how’ to raise one baby). 

     In my mind, I was imaging a very clean well-managed breeding facility for such a miracle to happen.  As I was talking with owner who I discovered, didn’t even know her mare was pregnant. The mare was aged (difficult to get pregnant). The birth was unattended and the owner knew very little about horses and their healthcare.  She really had no idea that twins were so rare in horses. She said that both foals were doing fine. Her only question was “how much should I feed my mare so she makes enough milk for two babies?” 

     Well, I was just amazed; I had never in my entire life seen two healthy twin foals.  I had to see it for myself.  I got directions and drove out that afternoon.  The mare was kept in a rundown old barn with a dirt floor stall that opened to a grass pasture that was full of broken down, rusty old farm equipment.  This was truly a miracle that the mare and two babies survived.  Sure enough the mare was standing grazing in the middle of pasture, only stopping long enough to herd her babies together and away from harm.  The twins were very small but equal size, and ever so cute.  They like to do things together, prancing around and playing.  They also nursed together, they either nursed from opposite sides, or the mare would actually let one foal nurse from behind, reaching between her back legs. Amazing--that mare was surely an Angel.    

(To be added - some pictures of this trio , farm equipment and all)

2)     Is it true that horses can’t throw up?  Why not?  Horses can not throw up.  If you ask me, it’s a poor design flaw.  Horses have a strong muscle or sphincter at the top of the stomach (called the cardia and thus the cardiac sphincter) that prevents back flow of ingesta.  I can only theorize the evolutionary advantage of this design.  When horses run at top speed, they create some pretty amazing pressures in the body cavities, or the abdomen.  Since in nature, they eat all the time, and need to take off running away from predators, the cardiac sphincter prevents them from throwing up the meal at top speed.  But now that our horses are domesticated, as a veterinarian, this design causes more problems than its worth.  You see, you or I, or our cat or dog, get sick and our small intestines don’t work right.  Stuff backs up into our stomach and we vomit.  Well, if a horse gets sick, or colics, the stuff backs up. If not treated medically ASAP, the stomach overfills and ruptures.  Bad deal if you ask me.

3)     Can you neuter or spay horses like you would a dog or cat?

 Yes, you can.  In fact, almost all male horses are castrated or neutered, resulting in the gelding.  Most people choose to castrate a colt before his second birthday as this is when a male horse starts to develop sexual maturity. And as all of you who have ever had a teenage boy in your house know, male hormones and the behaviors they develop are hard to manage.  Actually a 1200 lb animal can be quite dangerous, so most male horses are castrated.

     I was visiting a ranch with my 6yr old daughter, who was really attracted to a paint stallion and expected to be able to hug and kiss on him like her gelding at home.  I asked her to be careful of him because he was a stallion…..Boy, did that open a can worms I wasn’t ready for…….Mom, what’s a stallion?...........They use them to make baby horses………….”How do they do that”………….Yikes!!

     Mares have menstrual cycles fairly similar to women, only they don’t bleed. The cycle comes every 28 days.  One difference is that mares only cycle in the summer months, hence the term coming into season (it’s the season that they are cycling and ready to be bred).  Some mares have trouble dealing with the hormones that come with every breeding cycle, kind of like PMS.  And some mares actually have cramps or colic along with their cycles. 

     These are the mares that owners may chose to spay, or put on hormone supplements (like birth control) to keep from cycling.  Spaying of a mare is done differently than in a dog, really because of expense and size of the patient.  A mare is usually spayed standing and sedated, and the approach vaginal (similar to a hysterectomy in women).  As veterinary medicine advances, many surgeons are choosing to spay mares with the use of laparoscopy instead, like in women.

4)     Why do horses sleep standing up?  - In the wild, animals survive by “Fight or Flight”.  In veterinary medicine, we learn all about the body’s physiology and how it all relates to  the fight or flight instinct.  In nature, horses survive mostly by flight.  The exception being the herd stallion who stays back to fight while the herd flees.  

      Have you ever seen a herd of horses out to pasture, on a cool spring sunny day?  And all but one will lay down and sleep.  The standing one stands guard, but still may be sleeping.   By natural selections, the horses that could sleep standing up, wake up and run away from predators faster, survived. 

     Horses actually have a “stay apparatus’ in their back legs that allow them to lock their legs into extension and can sleep standing.  For any of us humans that survived sleep deprivation, you know you really can’t fall asleep on your feet. Once humans fall asleep, we find we're not on our feet anymore.

7) When a horse has strangles, is something choking off its air?? - The disease syndrome known as Strangles is caused by an infection of Streptococcus equi bacteria.  Recognize the "strep" part of that?  Like strep throat.  The bacterium infects the lymph nodes in the back of nasal passages and throat latch area, causing the lymph nodes to swell and fill with pus.  If the disease is left untreated, the lymph nodes can swell large enough to pinch off the wind pipe and they could die of suffocation or strangulation.  It’s a very bad, miserable, yet, preventable disease.  If you have a horse, talk to your veterinarian about vaccinations.

8) Here’s a question I had the other day ……….Do horses teeth really continually grow? - Horses are herbivores, or grazing animals. They eat plenty of roughage and never have trouble with a high cholesterol diet.  Because they eat mostly roughage, and the most efficient way to get nutrition from roughage is to grind it (like flour) into small particle, their teeth are well designed for grinding.   

     Because teeth are not made of metal, as they grind they wear, and by nature they eat a lot, grind a lot. If their teeth didn’t continue to grow they’d run out of teeth.  Now, eventually the teeth do stop growing.  Geriatric horses start loosing teeth about 25-27yrs of age.   The development and growth of teeth in a horse is very systematic and consistent, which we use to our advantage.  If a horse has normal dentition, good conformation of the jaw, we can very reliably age a horse by its teeth.  Have you ever heard, “Never look a gift horse in the mouth”?  Who wants to know how old their gift is?

To ask Dr. Rahal a question, email her at DesertHillsAnimalClinic@hotmail.com

Phone: 623-581-1558    Email: DesertHillsAnimalClinic@hotmail.com