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Breeding Horses/Possibly Pregnant Mare


Hello Lynne,
  I believe my mares may be pregnant. My eldest mare, an eight year old, she was a brood mare about two years before I had her, and is known to toss very large foals ranging from sixteen to sixteen and a half hands high for her small fourteen point three hands high frame. She is a mix of Paint and Quarter Horse. At our barn there is a new 'gelding' that is nearly four years old and just moved from being all by his lonesome in a pasture for the majority of his life. He has recently started mounting the three mares in the pasture. Two happening to be my own and the week he arrived my girls went into direct heat though they both had finished their heat almost a week earlier.  Now it's been almost a month and a half since they went into pasture with them and their seem to be slight changes in them. My eldest mare's teets are dropping and during her gestation periods as a brood mare I was informed that her milk sacs began to form very early on for she produces a large generous amount of milk. Her stomach seems bloated more so and she hasn't had a diet change, and about a month and a few days ago when I brought her into her stall she had a few nicks and scratches on her hind quarters and back. Along with my other mare, her being a three year old paint. She had a nasty bite one her mid-back and her teets have dropped as well. During further notice of their transformation in the beginning I doubted their pregnancies and resorts to checking the 'gelding' and he had a single ball that I hadn't noticed in earlier examinations. Please confirm my suspicions of their pregnancy or relieve me of them for I wasn't planning on breeding my mares. Both are my junior professional barrel and roping mares that I use in the high school rodeo coming this summer and how should i prepare for two foals? What do i need to do? When do i change their diets accordingly to gestation and birthing? Just a run down if you belive they are pregnant! :) thanks have a great day!

Dear Andie-Ray,

I have good news and bad news.  From your point of view, the bad news is, if there is really one testicle present, that gelding is NOT a gelding, he is a stallion. Did you palpate to make certain it was actually a testicle and not just some fat in the empty scrotal sac? Even one testicle means a stallion.  Although with one testicle present (regardless of whether the other is retained or gone) means reduced fertility, it does not stop the stallion from siring offspring. Before you shoot the "gelding's" owner, give them the benefit of the doubt and ask some questions.  There are reasons an inexperienced owner could believe they have a gelding. Could be his testes didn't descend until recently.  Some colts are bilateral cyptorchids (also known as "rigs")at birth but will drop one or both testicles later on.  This will normally happen by age two, but occasionally it may be even later. Very few real vets will ever miss a testicle during castration, but a ranch hand who routinely gelds all the colts on the ranch may not be as fastidious. Or, what I have seen is that when an owner finds out how expensive the surgery is to correct the problem, they just send the colt through the sale ring and say nothing. Several owners later, someone may figure it out when a mare turned out with only geldings shows up with a foal at her side. Many people think a gelding that mounts a mare must have had "something left."  That isn't the case.  Many geldings will mount mares.  Just because they are gelded doesn't mean they all have no interest.  Just like in people, the sex drive is between the ears, not the legs. Some geldings can be unruly and "studdy" and some stallions may have better manners than men at a cocktail party.

Now, for the good news. You didn't say where you live and it is now late March.  In some parts of the country that means lush spring grass.  Natural seasonal hormone changes and spring grass CAN cause the symptoms you describe. Very few pregnant mares show any signs of their pregnancy after only a month and a half. If you are lucky, it's just spring grass and hormones.  But if the "gelding" has a testicle, he is a stallion and if you don't want your mares preggers, separate them. Get your mares checked by a vet. There is no point wondering. Talk to the owner of the "gelding" in question and find out his history.  If there is a testicle, the owner needs to know. I there is one testicle showing, it is likely there is another one where that one came from. An undescended testicle can cause long term heath issues such as testicular cancer.

As for nutrition for pregnant mares, good nutrition is sufficient.  You may want to add optional vitamins, but if  their feeding program is well-balanced (pastures is what nature intended horses to eat) just keep an eye on them.  If they look healthy, glossy and are doing it right.

Good Luck and let me know how it turns out.

Lynne Curtis Gudes
"Common sense isn't."

Breeding Horses

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Lynne Curtis Gudes


Breeding, foaling, behavior, imprinting and common medical issues arising from foaling. Also stallion handling.


I have been involved in horses for approximately 45 years. I showed hunters, jumpers and stock horses. In the 80's I was licensed as a trainer on the race track. I have run broodmare operations, delivered foals and taught everything from what to feed and which end the shoes go on to advanced jumping. I tend to be impatient with owners who think their horses prefer to be locked up in confined spaces. Even my show and race horses rarely spent more than only the night before an event in a stall...the rest of the time they had room to run. In 1974 I rode a Quarter Horse Stallion and a Thoroughbred Mare solo from Minneapolis to San Francisco.


"The Long Ride" Published in Women Sports Magazine March of 1975 an article regarding the author's cross country horseback ride from Minnesota to California. "A Horse is a Horse,of Course" An article regarding investigating horse incidents and the Equine Liability Act for investigators and attorneys. published in The Legal Investigator, February 2004 "Investigating Animal Cases:" A chapter written at the request of the editors for a professional textbook entitled Advanced Forensic Civil Investigations published by Lawyers and Judges Publishing June, 1997 "Murder by Another Name:" An article published in The John Cook Fraud Report, December 1994 regarding the intentional killing of horses for greed and insurance fraud. "The Responsibilities of Horse Owners in Rural Communities:" A paper presented before the Regional Seminar of the National Association of Legal Investigators in November 1987 at Phoenix, Arizona. "The Old Gray Mare is Worth $10,000,000 Now." A professional paper on the investigation of cases involving bloodstock and racetracks presented before the National Conference of the National Association of Legal Investigators in Washington, D.C., June 1986.

approximately 3 years of confined degree. Advanced degree from the university of experience :>)

Awards and Honors
Recipient of the 1st place Anthony M. Golec Editor-Publisher Award 2004

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