| Featured Article - August
2005
In The Shadow of Equus |
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| The only clue I had that Aras might be having twins was that
she was moving so slow,” said Eileen Mellor who breeds Belgian draft
horses on her farm in Duncan on Vancouver Island, B.C. “She was due on
the 7th of May. It was the 9th and her teats were still waxed. I had
put Aras in her stall and had come in for supper. I thought she would
foal that night (and) I was going to check her at 8:00 pm. My nephew
was back and forth between our place and his and he passed the horse
barn. He called from the barn and said, “You’d better get up here. It’s
twins!” Amy and Anna were born some time between 6:30 and 7:15 pm. When Ms. Mellor arrived moments later, one filly was on her feet and the other was struggling to get up. They were both smaller than normal, about the same height, and one was heavier. Sorrel in colour, they looked the same with face markings and socks but their colouring will be more defined once they lose their baby fluff. They are growing at about the same rate and both eating well. Needless to say, Ms. Mellor is ecstatic. Twin foals are a rarity. It is even rarer that they actually survive birth and thrive. “It’s reported that 60% of mares with twin embryos deliver single live foals,” explained Dr. Claire Card in an email communication. She is an equine reproduction specialist at the Western College of Veterinary Medicine. “The embryos that start out next to each other are self-reduced; the embryos in separate horns or both sides of the uterus usually continue to term. (For mares carrying twins) 31% lose both pregnancies and 9% deliver both foals near term but they are usually premature. Of the foals brought to near term, both foals are born dead 64.5% of the time; one foal born alive occurs 21% of the time, and both foals born alive occurs 14.5% of the time. Twinning is second only to uterine infection as the leading cause of abortion in mares. Therefore live births of both twin foals with the twins making it past 10 days of age are extremely rare and are estimated to occur in about one in 300,000 births.” Ms. Mellor would likely agree with those statistics. She has been breeding Belgians since 1971. Amy and Anna are her 59th and 60th foals. On her 156-acre cattle farm she currently has ten Belgian mares and an 11-year-old stallion, De Broulliard Jasper. In 34 years of breeding, she has had five incidents of twins on her farm. Three of them were aborted, one set was still born, and the fifth set, Amy and Anna, made it successfully. Interestingly, this is 5-year-old Aras’ first pregnancy. |
As
a rule, mares are not particularly well suited to carrying twins. When
our Thoroughbred mare conceived twins, confirmed through ultrasound,
our vet strongly recommended ‘pinching’ off one and letting the
surviving embryo continue to term. The embryos were situated very close
together. But after the procedure, Daisy reabsorbed. It too was her
first pregnancy. “Retained placentas, foaling problems, and problems with conception following the foaling of twins have also been reported,” said Dr. Card of the special issues surrounding mares carrying twins. “This is why mares are so closely monitored for twins using ultrasound. Mares that have twins tend to repeat this year after year.” According to anecdotal evidence, large sized mares seem to be better able to cope with twins than the average horse. “We had a case several years ago where the owners thought their pregnant Appaloosa mare had colic,” recalled Dr. Clark. “They brought her to us and she delivered twins right into our hands. She may have had some discomfort in the final days leading up to delivery (causing the owners to suspect colic). They had tried to ultrasound her after breeding but she had kicked the vet and the pregnancy hadn’t been confirmed. She was a very large Appaloosa.” The extraordinary similarity between Amy and Anna has many wondering if they are identical twins. “To demonstrate that the twins are identical, one has to do either DNA testing or else evaluate an imprint of the fresh cut surface of the chestnuts, similar to fingerprinting in humans,” continued Dr. Claire Card. “They must, of course, be the same sex (having developed from a single split embryo) and be the same basic colour. Identical twins do not necessarily have the same white markings. Variations have been reported. Some confuse the birth of symmetrically sized, same sex, similarly marked foals as ‘identical’. It’s common in the horse to also have asymmetric twins where one is small and the other is smaller. There is at least one published scientific report of confirmed identical twin foals.” As for Amy and Anna, they are very bonded to each other, whether they know they are identical or not. Ms. Mellor is still giving consideration whether to do a DNA test. “They don’t like being away from each other but don’t mind being away from Aras,” she said. “The mare isn’t really concerned either.” The only thing that everyone is concerned about is that the unique twin fillies continue to grow and thrive. Read Margaret Evans' column "In The Shadow Of Equus" each month in The Pacific & Prairie Horse Journal |
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