The Horse:Your Guide To Equine Health Care provides monthly equine health care information to horse owners, breeders, veterinarians, barn/farm managers, trainer/riding instructors, and others involved in the hands-on care of the horse.
Issue link: https://thehorse.epubxp.com/i/821826
9 June 2017 THE HORSE TheHorse.com "Research has shown that heavier foals have an increased prevalence of conformational defects and nonseptic musculo- skeletal disorders," said Sarah Smith, MA, VetMB, MVetMed, Dipl. ACVIM, MRCVS, of Rossdales Equine Hospital, in Newmarket. Smith and colleagues evaluated 66 Thoroughbred brood- mares' body condition scores and blood work starting at 40 days of pregnancy. These results contradict previous study results suggesting higher body condition scores didn't affect foal birth weight, Smith said. However, there was a signifi- cant difference in her study: The mares were already obese when they became pregnant. In previous studies researchers managed mares experimentally during pregnancy to become obese. Further, recent research has suggested that the mare's metabolic status in early gestation plays an important role in "programming" the fetus. "In other mammals, we have known for a long time that maternal under- or overnutrition can affect the offspring, and there is increasing evidence that this also occurs in horses," Smith said. "The aim should be for mares in midrange body condition, avoiding either the lower or upper extremes which may cause problems for the fetus or foal." Smith added it's a common misconseption that larger foals are healthier: "This desire for 'big, strong, healthy foals' prob- ably stems from the association of small foal size at birth with immaturity and subsequent problems in the immediate post-foaling period. This has led to the assumption that if a small foal may have problems, a big foal must be better." The increased health risks larger foals face don't appear to balance out with perceived better competitive results, she added. In racehorses, for example, studies have shown that "higher birth weight does not confer a performance advan- tage, where there is no association between birth weight and racing performance," she said. She recommended owners track broodmares' body condi- tion during pregnancy using the Henneke body condition scoring system. This can be tricky, she cautioned, because of a growing abdomen, but other indicators such as localized fat deposits and the presence of a cresty neck can help. —Christa Lesté-Lasserre, MA Researchers know that injecting a substance called polyacrylamide hydrogel (PAAG) into an arthritic joint can offer long-lasting pain relief. But in a recent study researchers revealed possible clues as to why, suggesting the horse's body reacts to the gel by building new layers of natural synovial cells over the synthetic gel, said Lise Christensen, PhD, of the University of Copenhagen, in Denmark. Christensen and colleagues examined 13 joints from seven horses treated with PAAG sev- en days to two years prior to being euthanized for reasons unrelated to PAAG or joint pain. Initially the gel appears to integrate within the synovial lining gradually, creating a sort of "sublayer" under a new generation of synovial tissue, Christensen said. And in the next few weeks, it appears to create a layer within the synovial lining. But as months pass, the gel layer separates from the synovial cells, which form their own layer, she said. Additionally, the num- ber of inflammatory cells in the area drops and a fibrous connective tissue network develops within the gel layer. While researchers are seeing PAAG's positive effects in arthritic joints, it's still unclear exactly how the substance helps relieve pain. "My theory is that the gel cushions the joint, but there is no indication that it replaces worn- down cartilage," Christensen said. However, the fact that her group's histological (microscopic) study shows the new synovial layer forming over the PAAG could help shed light on the exact pain-relieving mechanisms at work. Learn more about PAAG at TheHorse. com/39103.—Christa Lesté-Lasserre, MA B igger isn't always better—and that ap- pears to be the case for both broodmares and their foals. British researchers have confirmed that overweight broodmares are more likely to have heavier foals, which could suffer from lifelong musculoskeletal problems. NEWSFRONT Inquiries to: 859/276-6726 E-Mail: News@TheHorse.com ERICA LARSON, News Editor @TH_EricaLarson ANNE M. EBERHARDT/THE HORSE PAAG Showing Promise as Arthritis Pain Reliever ISTOCK.COM Broodmare Weight and Long-Term Foal Health Issues Linked Researchers believe PAAG has a cushioning effect to relieve pain in arthritic joints.