Equusの Autumn 2020 の目次

SEASONAL CARE FOR ARTHRITIC HORSES Warm weather may be lingering, but if you’ve got an older horse with arthritis, it’s not too soon to begin formulating a plan to help him cope with the challenges of the winter ahead. Here are three things you can do to help keep your older, arthritic horse healthy and comfortable as winter conditions set in. 1. Start (or update) a supplement regimen. A huge selection of joint-support supplements are available. It can take several weeks for the effects to “kick in,” so now is the time to think about choosing one---conferring with your veterinarian if necessary. Also, new formulations come on the market each year. If your horse has already been on a supplement, review what’s now available to ensure that it’s still the…

Year-round diagnosis of pituitary pars intermedia dysfunction (PPID, also known as Cushing’s) just got easier, thanks to the joint efforts of equine researchers in England and mathematicians in Australia. Caused by an enlarged and overactive pituitary gland, PPID is characterized by overproduction of adre-nocorticotrophic hormone (ACTH). This hormonal imbalance can lead to a slew of complications, including a long-haired, slow-to-shed coat, muscle weakness and compromised immunity. PPID also increases susceptibility to laminitis. Although typically found in horses 15 years old or older, PPID can also occur earlier in life. PPID diagnosis usually requires tests that measure the ACTH levels in a horse’s blood. These levels naturally fluctuate by season, however, which can make interpreting results difficult. “The pituitary gland controls several processes that are seasonally variable---such as reproductive hormones,” explains…

“Chestnut mare, beware.” If you’ve ever used this phrase or nodded knowingly in agreement when you heard it, you’ve been perpetrating a scientifically inaccurate and potentially harmful stereotype, according to new research from the University of Sydney. For the study, researchers asked 1,233 riders to complete a 151-question survey. The Equine Behavior Assessment and Research Questionnaire asked respondents a variety of questions about the behavior of their horses under saddle, in-hand and in general, along with those related to demographics such as sex, age, breed and coat color. “The motivation of the study was to explore whether there is any merit to the common belief that mares have undesirable behavioral traits compared to geldings,” says Anna Sundqvist Aune, who was part of the research team. The unfounded stereotype that mares…

Here’s a quick look at the types of active, “living” ingredients you may see listed on a probiotic product for horses: Lactobacillus is a genus of anaerobic, rod-shaped, non-spore-forming bacteria that help convert sugars into lactic acids. These bacteria are the most common probiotic found in food such as yogurt. Common species included in probiotic supplements include plantarum, casei, reuteri and acidophilus. Enterococcus is a large genus of spherical-shaped bacteria capable of living in oxygen-rich and oxygen-depleted environments. Although useful in the digestive tract, when Enterococcus bacteria spread to areas other than the gut, they can cause troublesome infections. There are at least 17 different species of Enterococcus; two you’ll commonly see in probiotic products are faecium and lactis. Bifidobacterium is a genus of non-aerobic, y-shaped bacteria that are ubiquitous…

In this age of pandemic, everyone has become familiar with, if not expert in, measures that control the spread of disease: Social distancing. Disinfection. Quarantine. These fundamentals of biosecurity might once have been abstractions but now have taken on practical importance in our lives. Of course, the horse world has long made the control of certain diseases a priority. And thanks to another pillar of disease prevention---vaccination---we’ve largely been successful in protecting horses from rabies, equine encephalomyelitis, West Nile virus and other infectious scourges. Yet some pathogens continue to pose a threat despite even the most stringent hygiene measures and vaccination programs. Equine herpesvirus-1 (EHV-1) is one such organism. Even without physical contact, this highly contagious respiratory virus can spread rapidly from horse to horse through nasal discharge or aerosol…

Rarely do those involved in events of major historical significance realize just how far-reaching their actions will turn out to be. When in 1867 the famous Morgan stallion Ethan Allen was matched against Dexter, the Hambletonian speed merchant, the contest captured the public imagination. On June 21st, more than 40,000 people turned out to see the two harness racers, both of whom had previously set world records, battle it out at the Fashion Course on Long Island, New York. The fans were boisterous, opinionated and ready to lay money on their favorite; more than a quarter of a million dollars in wagers reportedly changed hands that day. The match was set for $2,000, best three out of five heats. Odds ran two to one in favor of Dexter, who, it…

This article focuses on Dexter and the beginnings of the American Standardbred, but one must consider how great a horse Ethan Allen truly was in order to fully appreciate what Dexter was pitted against. In this print portraying an exciting “dead heat,” Ethan Allen goes with running mate to wagon against a horse named Lantern and mate. Lantern, it should be noted, was by Black Bashaw by Young Bashaw, tracing back to Khasnadger, one of the few “Asil” Arabians that were present in America before the World’s Columbian Exposition of 1893 (see “America’s Major Horse Breeds Emerge,” EQUUS 473). Lantern’s paternal grand-dam traces in tailfemale to Messenger, and he is out of a Canadian-Morgan mare. Lantern’s pedigree thus represents the diversity of blood which is the norm among Standardbreds. J.…

The color-coding of Dexter’s pedigree reveals at a glance the great diversity of broodmare ancestry that characterizes the lineage of Standardbred horses. Their sire-line ancestry is much narrower; all Standardbreds trace in sire-line to Rysdyk’s Hambletonian foaled in 1849, and through him to Messenger, foaled in 1780 and imported in 1787 or 1788. Dexter’s tail female composition is Old Canadian 31.25%; Barb 21.875%; Hobby 21.875%; “Diplomatic” Arabian 9.375%; Turkmene 6.25%; Norfolk Trotter 6.25%; and Colonial American Thoroughbred 3.125%. The most famous “diplomatic” Arabian was the Darley, a Turkmene who carried no more than 25% “Asil” blood (to review the breeding of Thoroughbred foundation sires, see EQUUS 449, “Foundation Sires and Dams”). Colonial American breeding indicates that the tail-female ancestry goes back to the early imports Jolly Roger, Fearnought, Morton’s Traveller…

When COVID-19 swept through the United States, it took a toll on human life and the economy. As hospitals sprang into action, businesses shuttered and the scramble for provisions began, animal rescue organizations started bracing for the worst, knowing that surrenders and possible starvation cases may not be far behind. At Drifter’s Hearts of Hope, a 501(c)(3) equine rescue in Franktown, Colorado, President Jacqui Avis and Director of Fundraising Rachelle Nye sought to head this problem off at the pass. They knew better than most that it’s seldom cheap to feed or care for horses, having rescued more than 460 to date. “We had experienced an increase in owner-surrender requests [people who ask to relinquish ownership of a horse to the rescue] and had seen a decrease in people interested…

A BETTER WAY TO READ THE SIGNS OF LAMENESS Equine lameness can be difficult to detect, but a study from England confirms the reliability of a relatively new tool for identifying subtle signs of musculoskeletal pain in horses. Developed at the Animal Health Trust in Newmarket in 2018, the Ridden Horse Pain Ethogram (RHpE) is a compilation of 24 behaviors, such as “head tilting,” “tail swishing” and “spontaneous changes of gait,” that have been proven to correlate with musculoskeletal pain (see “A System for Identifying Lameness,” opposite). If a horse exhibits eight or more of the behaviors, chances are good he is lame. Undiagnosed lameness has a far-reaching impact on the lives of horses and their riders, says Sue Dyson, VetMB, PhD. “One of the reasons I was incentivized to…

A new study from the Netherlands has found that the long-term prognosis for horses who survive colic surgery is good, but a full return to athletic function may be more difficult. Researchers at Utrecht University collected data on 283 horses who underwent colic surgery at the clinic there. Fifty-nine percent of the horses survived to be discharged. Of the horses who could be tracked after returning home, 96 percent were still alive a year later and 63 percent achieved the same or an improved level of performance as before surgery. But the return to work didn’t always go smoothly for the study horses: Altered behavior and gait-related problems were reported by the owners in 46 percent of the cases. The researchers did not investigate whether these problems were associated with…

An excellent and evocative Currier and Ives portrait of Dexter with Budd Doble. The horse’s flattened ears and oversized, wild-looking eye are conventions of 19th-century racing art. Doble has been recognized as the finest “whip” ever to hold the “ribbons.” He is credited with being a master of pace, knowing just when and how to ask for more effort. He had sympathetic hands and a soft way of speaking that won the confidence not only of Dexter but of many other difficult horses. Race times got faster when wooden racing carts were replaced by featherweight steel sulkies fitted with bicycle tires, but the horses never came any tougher than in the days of the old high-wheelers. (Courtesy, Library of Congress) Dexter in harness against General Butler on October 27, 1865,…

During his first Presidential campaign, Ulysses Grant had become the frequent guest of wealthy barons of East-coast industry and enterprise; Robert Bonner owned the prestigious and profitable New York Ledger, one of the country’s first literary “news magazines.” Shortly after Dexter’s match races against Ethan Allen, Bonner purchased him for the stratospheric price of $35,000. This removed the gelding from official competition, in which Bonner never engaged, preferring instead to use his horses for personal pleasure. This did not, however, mean that Dexter’s racing days were over, for Bonner would match him against all comers. Most of these private contests were held on Harlem Lane, in what was then rural New York. Large amounts of money changed hands in each race, but Bonner insisted that a $10,000 guarantee be deposited…

Comparison of Ethan Allen and Dexter is one of the most interesting studies we’ve had the opportunity to present. The two horses are amazingly similar in some ways. Most importantly, they are both nearly level in overall body balance, meaning that thrust from the hind legs will tend not only to push the horse forward but to cause him to rise in front. This lightens the load on the forelimbs and speeds the breakover of the fore hooves, protecting the horse from injuries to the tendons while also allowing him to reach forward with the forelimbs farther and more easily. The horses are coupled similarly too, both being broad and smooth across the top of the back in the ribless area just in front of the points of hip (the…

Taking a look inside a horse’s intestinal tract may soon be as simple as getting him to swallow a tiny camera, waiting for it to pass through his digestive system and then downloading the images it captures along the way. A study from the University of Calgary, in Canada, explored the feasibility of wireless capsule endoscopy in diagnosing ulcers, parasites and other digestive problems in horses. The capsule tested by the Calgary group uses four cameras and a LED light system to capture 360-degree images of its environment. Images are stored on a built-in memory system, eliminating the need to restrict a horse’s movements to ensure proximity to an external sensor. In addition, the capsule goes into power-saving mode when it is not in motion, maximizing battery life. For their…

Horses are not just smart; they are learning machines. They scout for cues everywhere and soak up information. Once acquired, new knowledge sticks to a horse’s brain like superglue. If there’s a problem with equine learning, it’s that horses learn too quickly---and forget too poorly---to accommodate human errors. In equine environments, horses remember where fresh water and grass are located, what times of year such resources are available, where the best shelter is found and how to get to it. They learn where every horse in their group ranks in the social hierarchy and know complex kin relationships and behavioral rules within an entire herd. They recognize the distinct smell of each animal in their environment, not just different species but also different individuals within a species. They recall which…

Your horse’s digestive system is remarkably efficient. From grass, hay, grain, salt and water, the equine gut can extract or synthesize all the calories and nutrients necessary to keep the typical pleasure horse healthy and in good body condition. And it functions pretty much flawlessly under a wide range of conditions--- both internal and external. Much of the credit for this digestive efficiency goes to the colonies of bacteria, protozoa and fungi---collectively referred to as intestinal flora---that reside within the horse’s intestines. These microorganisms are continually consuming, excreting and reproducing, as all living things do. Your horse isn’t unique in hosting this diverse and dynamic microbiota: Researchers estimate that there are approximately five billion such organisms per gram of digestive fluid in every mammalian digestive tract. The natural activities of…

This Currier and Ives print portrays Ethan Allen and Dexter in their first match at the Fashion Course, Long Island, on June 21st, 1867. Note the race officials in the observation booth above the track, the timer looking down at his stopwatch, which was accurate to 1/60th of a second. The horses, shown going at top speed, are unrealistically drawn as they always were 150 years ago, before the invention of film, video or “instantaneous” photography that could capture motion. The print does, however, render the horses’ colors and markings very accurately and presents good portraits of drivers Budd Doyle and Dan Mace. It also captures in an artistic way the attitude of the horses and the extreme effort they were making. (Courtesy, Library of Congress) The second contest between…

Ethan Allen, from an original Schreiber and Sons photograph made when the horse was 10 years old, in the prime of his life and at the pinnacle of his racing career. Key to Pedigree Color Codes Examining the pedigree of Ethan Allen’s ancestor Justin Morgan (a.k.a. “Figure,” f. 1789) reveals still more emphatically the debt that Morgan breeding owes to the Old Canadian. Justin Morgan’s pedigree contains one speed bloodline to Old Bald Peg, but is otherwise mostly English Hobby. His tail-female ancestry is less diverse than Ethan Allen’s, consisting of 50% Old Canadian, 37.5% English Hobby, 9.375% Barb, and 3.125% Spanish. (See EQUUS 469, “The Mystery of the Morgan Horse,” for a complete review of Justin Morgan’s probable ancestry.) Pedigree of Ethan Allen. This pedigree and those of Justin…

The horse-human relationship is unlike any other. Horses can be our friends, our legs, our confidantes, our partners-in-crime, our teachers and our healers. They have an amazing ability to rehabilitate the human body and soul. The following stories were submitted to Hope in the Saddle as nominations for the Therapy Horse of the Year award. These four finalists exemplify the inspiring power of the horse-human bond. (Stories have been lightly edited for length and clarity.) PRINCESS XELLIE Princess Xellie—Xellie for short—is a truly magical pony princess. As any good princess should be, Xellie is patient, smart and capable, and shows genuine affection for her friends. A diminutive 10.2 hands high, this small-but-mighty princess is an amazing therapy pony. Xellie is wonderful with all her riders but is legendary here for…

Fallen, wilted or dried leaves from the red maple (Acer rubrum) contain toxins that can cause fatal poisoning in horses and ponies as well as donkeys and mules. Horses are most likely to encounter wilted leaves after summer storms bring down branches or blow leaves into pastures and paddocks. In the autumn, fallen maple leaves are generally less palatable to horses, but they also pose a serious threat if they are consumed. For an average horse, a leaf or two is not likely to cause harm but ingesting one to two pounds of wilted or dried leaves can result in severe illness or death. Although the dangers of poisoning from the red maple, also called swamp maple or soft maple, are well known, research suggests that other trees of the…

If there is such a thing as an expert in international equine cuisine, it might be Gulsah Kaya Karasu, DVM. She has traveled the world for the past 15 years, first training to become an equine veterinarian and nutritionist, then sharing what she’s learned with horse owners in a variety of settings. In the process, she has witnessed firsthand the different norms for filling hay nets and feed buckets. She has also learned that despite cultural differences, many horsekeeping challenges transcend borders. Born in Turkey, Karasu earned her veterinary degree in Istanbul before deciding to specialize in equine nutrition. “I want to help horse owners understand how nutrition plays a vital role in the health and well-being of their horses.” Working toward that goal, she has since traveled tirelessly to…