Equusの Wellness Issue 2022 の目次

Check your horse’s feet closely each day and you’ll be more likely to notice changes that signal problems early. It doesn’t take long. In a routine examination you need only focus on four readily visible parts of the hoof: 1 The wall is the hardest part of the hoof and provides structure and protection to the inner foot. A healthy hoof wall will be cone-shaped, with firm, straight sides that show no cracks, bulges or flares. 2 The next hardest structure is the sole, which protects the bottom of the foot. Ideally, the sole will be about a quarter of an inch thick with a smooth, firm but flexible texture. The thickness of a horse’s sole can vary from more than an inch to less than a sixteenth. Horses who…

Any bleeding wound is cause for concern, but some are worse than others. Whenever you’re in doubt about the severity of an injury, call your veterinarian. Wounds are classified from superficial to severe based on these characteristics: • Age: If a wound goes undiscovered or untreated for more than eight hours, bacteria have had time to proliferate, increasing the risk of infection and other complications. • Bruising: The area around a laceration caused by a kick, collision or other high-impact trauma is likely to be bruised. The same healing resources needed to repair open wounds are required to heal bruises, which occur when blood vessels beneath the skin rupture. • Complexity: Clean cuts from sharp objects typically heal faster and better than torn flesh with ragged, uneven edges. • Contamination:…

▸ Definition: obstruction of the esophagus, usually by feed. ▸ Causes: bolting food, attempting to swallow a corncob, apple or large carrot pieces, inadequate mastication due to poor dental health, eating after sedation, a physical condition that restricts the esophagus. ▸ Signs: A horse with choke stops eating and looks anxious—coughing, retching or shaking his head. He may also stretch his neck and paw. As material backs up, it may come out of his mouth or nose. ▸ Treatment: Sedation and/or medications can help to relax the esophageal muscles so the obstruction can pass. The veterinarian may also flush water into the esophagus through a nasogastric tube to help soften the mass. ▸ Prevention: Slice apples and carrots into small pieces before offering them as treats and slow down a…

Hoof bruises typically don’t cause long-term problems, and they generally heal on their own once the aggravating factor is removed. But they can interrupt your riding schedule for a few days. Here’s how you can protect your horse’s hooves from bruises. 1. Be mindful of what’s underfoot. Most bruises are caused by unforgiving footing. A single step on a rough rock can lead to bruising, as can exertion over a consistently hard surface, such as a frozen field. If your horse’s footfalls produce a “ring” rather than muffled hoof beats, the surface you’re riding on is too hard for fast work; stick to a walk until you find softer going. Likewise, when you are covering uneven and/or gravely footing, keep your speed to a minimum so your horse can pick his…

Brought to you by ▸ Immediately: Move the horse into shade. This can be under a tree, in a barn or even in the shadow of a horse trailer. ▸ Immediately: Douse the horse with the coldest water available. Direct application of cold water to the horse is the fastest and most effective method of lowering body temperature. The notion that putting cold water onto hot muscles can cause cramping or laminitis has been debunked, so use as much of the coldest water as you have. ▸ Immediately: Use any other cooling aid you have on hand. If you have ice (or can send someone to get some quickly), put packs along the horse’s head and throat, where major blood vessels serving the brain run close to the surface. Standing…

Brought to you by ▸ Immediately: Allow your horse to stand exactly where he stopped. He can’t “walk out of” these muscle cramps. In fact, making him move would only compound the damage to his muscles. Your veterinarian will advise you later on how to move him if it’s absolutely necessary. ▸ Immediately: Warm or cool the affected muscles, depending on the season. If your horse ties up in cold weather, throw a blanket over his hindquarters to help ease the cramping. Likewise, if the episode occurs in hot conditions, sponge his cramped muscles with cold water. And don’t worry: Contrary to popular belief, there is no evidence that applying cold water to hot muscles causes or worsens cramping. Observe without intervening Don’t do any massage. Manipulation of the horse’s…

Brought to you by ▸ Immediately: Most colicky horses will not eat or drink, but as a precaution, remove all food and water from the stall. Any intake could worsen an impaction or blockage. ▸ Immediately: Determine whether walking might help. As a general rule, if a colicky horse is lying down or standing quietly, there is no need to walk him—just let him be. If, however, the horse is restless and repeatedly lies down and rises, walking might help distract him and, in that way, make him feel a bit better. That said, if your horse is extremely agitated he is a danger to everyone around him: Put him in an indoor arena, paddock or another open area and stay clear until the veterinarian arrives. Do not give your horse…

▸ Immediately: Check his nose. Most cases of respiratory distress in horses are due to equine asthma (also known as heaves), but breathing can also be inhibited if an allergic reaction, insect sting or injury causes inflammation of the nostrils. If the horse’s nose appears swollen, or if he is bleeding from one or both nostrils, you’ll want to alert your veterinarian, who can prepare for a possibility other than heaves. ▸ Immediately: Keep the horse quiet and still. Exercise or excitement will make breathing even more difficult. Allow the horse to simply stand quietly. Bring out a friendly horse to keep him company if that will help keep him calm. Do not give the horse sedatives or tranquilizers, however. These may further inhibit his respiration. ▸ Immediately: Get him some…

Common causes of severe limb inflammation in horses include: • Stocking up. This is the colloquial term for a diffuse, soft, cold swelling of the lower limbs that results from inactivity. Usually both hind legs are affected, but occasionally the forelegs can be as well. The swelling is typically limited to the fetlocks and below and is not associated with any lameness. Once the horse begins to walk, which boosts the function of the circulatory and lymphatic systems, the swelling subsides. • Injury. Trauma to a tendon, ligament or bone usually causes sudden, significant swelling, which is typically accompanied by localized pain and lameness. The affected area is also warm to the touch. The swelling will typically resolve as the underlying injury is treated and heals. • Lymphangitis. Inflammation of…

1. Know your horse’s specific risk status. All horses need to be protected from laminitis, but some require more vigilance than others. The poster horse for high laminitis risk is an inactive and overweight easy keeper. Horses with insulin resistance---a condition in which liver and fat cells do not respond normally to insulin---are also at greater risk, as are those with pituitary pars intermedia dysfunction (PPID, also known as Cushing’s disease), an endocrine disorder that leads to excess production of the hormone cortisol. And, of course, any horse who has had laminitis in the past is at a high risk for recurrence. 2. Limit his access to lush pasture. The majority of laminitis cases are so-called “pasture laminitis,” triggered by sugars and starches in grasses. Although lush spring pasture is most…

▸ Immediately: Keep the horse as calm and still as possible. Do not walk him or allow him to take a single step on his own. Instead, ask others to make the area around him as safe as possible. If it will help, offer the horse hay and water and/or bring another horse to stand nearby. You may be tempted to hold up the injured limb to keep the horse from putting weight on it, but keep in mind that 10, 15 or even 30 minutes may pass before help arrives. You might also put yourself at risk if the horse is unstable. If he is holding up the limb himself, it’s best to just let him be. ▸ Immediately: Stay with the horse. Use your cell phone or scream for…

Three major classes of deworming chemicals (anthelmintics) are used in horses: Avermectins and milbemycins are still largely effective against a wide range of parasites. However, resistance—especially in ascarids—is documented and growing. This class includes: • Ivermectin, which works against most of the common equine parasites except for tapeworms. It does not work against encysted small strongyles, however. • Moxidectin, which is similar to ivermectin but also acts against encysted small strongyles. Benzimidazoles are effective against many adult parasites, but their efficacy against larval stages is declining. This class includes: • Fenbendazole, which kills large strongyles, pinworms and ascarids. • Oxibendazole, which kills large strongyles, pinworms, ascarids and thread-worms. • Oxfendazole, which kills large strongyles, roundworms and pinworms. Pyrimidines, also called pyrantel salts, have several applications and are the only class…

What influence can feed have on soundness? Quite a bit, in fact, particularly when you’re dealing with youngsters. Specifically, diets high in glucose, carbohydrates and/or starch have been linked to developmental orthopedic disease (DOD) in growing horses. DOD, which is also associated with mineral imbalances, occurs when growing bones’ cartilage-forming mechanism is over-stimulated or the conversion of cartilage to bone is somehow disrupted. If DOD is caught early enough and dietary changes are made, the damage can often be minimized or even reversed. In many cases, however, a foal with DOD grows into a mature horse who is never sound or who becomes lame with the lightest work. Obviously, it’s far better to prevent DOD in the first place. To do so, anchor the rations of growing horses with the…

Brought to you by ▸ Immediately: Make sure the horse’s nostrils are clear. If the hives are part of a systemic allergic reaction, his airway may swell shut. Look for signs of puffiness around the nose and mouth, listen for strained, raspy inhalation, and watch the horse’s sides to see if he is taking even, deep breaths. ▸ Immediately: Rinse the affected area. Many cases of hives are a reaction to something on the surface of the skin (contact dermatitis). If the wheals appear to be localized, douse the area with cool water or cleanse it with a mild soap and rinse thoroughly. Consider possible causes Hives are an immune response to a topical or systemic allergen. Investigate whether something in your horse’s environment may have led to the reaction. The…

▸ Immediately: Isolate the horse. Contagious diseases, such as strangles and equine herpesvirus, can be transmitted through nasal fluids. Move the horse as far from the others as possible. After handling him, avoid contact with the rest of the herd until you’ve showered, changed your clothes and scrubbed your shoes. ▸ Immediately: Remove the horse’s water and feed bucket from the barn. Germs can linger on these surfaces and infect other horses. Later, cleanse the ailing horse’s stall and any equipment used on him with disinfectant solution. ▸ Immediately: Check the rest of your herd. Have someone who has not been exposed to the sniffling horse take the temperatures of all the others on the farm. Tell the veterinarian about any with a temperature above 101.5 degrees Fahrenheit (normal is 99 to 100…

▸ Definition: Heat exhaustion occurs when a horse’s natural cooling system—primarily sweating—can no longer keep his body temperature in check. Specifically, when a horse’s core temperature reaches 104 to 108 degrees, heat exhaustion sets in and dangerous physiological changes occur. ▸ Causes: prolonged exertion in hot, humid conditions. Humidity keeps sweat from evaporating and, therefore, cooling the horse. ▸ Signs: Respiration increases to between 60 and 80 breaths per minute (compared to the normal 15) when a horse has heat exhaustion, and he will likely stand quietly with his head lowered and seem oblivious to his surroundings. If a fold of skin pinched at the shoulder remains “tented” for more than a few seconds, he may also be dehydrated, a condition that often accompanies heat exhaustion. In some cases, a…

▸ Definition: Tying up is a metabolic malfunction that leads to cramping of the large muscle groups, particularly in the hindquarters. ▸ Signs: profuse sweating, halting gait, refusal to move, elevated pulse ▸ Causes: Tying up is often associated with overexertion, mineral imbalances or a return to work after a rest period. In draft horses, equine polysaccharide storage myopathy (EPSM) is a common cause of tying up; in Quarter Horses, it is linked to polysaccharide storage myopathy (PSSM). ▸ Treatment: rest, muscle relaxants and supportive intravenous fluid therapy to dilute toxins from muscle damage and support kidney function…

▸ Definition: The term “colic” refers to any abdominal pain. More specifically, a horse can have • gas colic, a buildup of gas, typically in the stomach, large intestine or cecum • spasmodic colic, cramping of the smooth muscles of the digestive tract • impaction or obstruction colic, a blockage of the digestive tract by accumulated sand, enteroliths or parasites • entrapment colic, which occurs when a section of intestine slips through a space in the gut and is deprived of circulation. ▸ Causes: abrupt changes in management routine or feeding, poor-quality feed, lack of turnout, parasite load, tooth problems that impede chewing, gastric ulcers, cancer, enteroliths or sand ingestion. Many times the cause of colic—particularly with entrapment and twists—is never known. ▸ Signs: Most horses with colic will be…

▸ Definition: “Heaves” is the common term for equine asthma, a respiratory disease characterized by a narrowing of the small airways of the lungs, which makes exhaling difficult. ▸ Causes: Tiny dust particles pulled deep into the airway trigger inflammation in the lungs. Research suggests that some horses inherit an increased sensitivity to dust, which makes them more susceptible to equine asthma. ▸ Signs: fast, deep breathing along with coughing and mucous discharge from the nose. In advanced cases, a horse’s nostrils flare and an audible “wheeze” may be heard with each breath. Horses with chronic heaves can develop a distinct “heaves line” along the abdomen as the muscles that help them exhale get overused. ▸ Treatment: Steroids and bronchodilators can be used in “rescue” situations, but longterm treatment of…

Brought to you by ▸ Immediately: Keep the horse as still as possible. Years ago, it was believed that walking a horse with laminitis would improve circulation, but we now know that movement only compounds the damage to the internal structures. If possible, leave your horse exactly where you found him until help arrives. If you must move him, take the shortest possible route to your destination or transport him via trailer. If the horse wants to lie down and will do so quietly, let him. ▸ Immediately: Stand the horse in ice water. Research has shown that chilling down a horse’s feet can slow the initial progress of laminitis. Icing is most effective in the earliest stages of the disease, but it cannot hurt even if you are not…

▸ Immediately: Carefully halter the horse and hold him so he cannot rub his eye on anything, including his own knees. Rubbing can worsen the eye’s condition, particularly if a foreign object is embedded in it. ▸ Immediately: Inspect the eye and surrounding area. If the horse allows you, gently pry the eyelid open to look for a foreign object. If you see one, do not remove it—simply inform the veterinarian when she arrives. Also, press gently on the bones around the eye, head and poll, looking for tenderness. Tell your veterinarian what you find. If nothing is embedded in the eye: Rinse with saline solution. Flushing dust, grit and debris from an injured eye can provide immediate pain relief. But use only sterile saline that has been properly stored.…

Hairline: Typically vertical, a hairline fracture extends only partway through the bone. Generally these fractures heal well because of their natural stability. Greenstick: Trauma can cause immature bone to bend. As the bone “gives,” the side of the shaft opposite the blow pulls apart, resulting in a greenstick fracture. Young and healthy bones usually recover well from these fractures. Transverse: A clean break across the bone shaft, a transverse fracture normally mends quickly when the ends are immobilized in perfect contact with each other. Spiral: Also known as an oblique fracture, a spiral fracture occurs when twisting forces crack the bone into two pieces at a sharp angle. Both the angle of the fracture and the jagged edges make this a challenge to stabilize and heal fully. Comminuted: A blow…

Four species of internal parasites pose the most serious threat to your horse’s health. • Small strongyles (cyathostomins). These are the most prevalent parasites in horses and the focus of much of a deworming protocol. A few small strongyles do little harm to a horse, but in large numbers they can interfere with the absorption of nutrients, causing a horse to be unthrifty. These worms spend a portion of the life span encysted in the intestinal walls, where they may not be affected by certain classes of chemical dewormers. • Ascarids (Parascaris equorum). These worms mainly affect foals, with adult horses developing a natural immunity as they mature. Ascarids can cause slow growth, a dull coat and decreased energy. • Tapeworms. Infection with these segmented parasites can cause general unthriftiness…

Although you might think only racehorses and other elite athletes are susceptible to gastric ulcers—erosions of the lining of the stomach—any horse can develop them. Risk factors include transportation, competition or high-intensity training, hospitalization and a low-forage diet. That said, the predisposition to ulcers varies, due to physiological factors and even personality type. For example, a horse who is too anxious to eat while away from home may be more susceptible to gastric ulcers than a calmer companion who settles down readily with his hay net. Sometimes ulcers have little, if any, outward effect on the horse’s health or performance, but they can also cause constant pain, a condition called equine gastric ulcer syndrome (EGUS). The effects of ulcers can include poor appetite, intermittent mild colics, weight loss, poor performance,…

Brought to you by ▸ Immediately: Apply direct pressure to staunch bleeding. Use a clean cloth—a towel, your shirt, even a saddle pad—to press gently but firmly on the wound. If the cloth becomes soaked with blood, place another directly over it. An alternative is to use a bandage to hold the cloth in place. However, do not apply a tourniquet unless specifically instructed to do so by the veterinarian. ▸ Immediately: Move your horse to a safe treatment area, if possible. Ideally, your veterinarian will be able to tend to the wound in a well-lit, quiet area with access to running water. At the very least, the treatment area needs to be clear of obstacles and debris. If your horse is not in an area where treatment can be…

▸ Immediately: Prevent the horse from eating or drinking. Remove or empty feed and water buckets and do not allow the horse to graze. Anything ingested will come up against the blockage, making the situation worse. ▸ Immediately: Encourage the horse to stand quietly with his head lowered. This will reduce the likelihood that material from the blockage will be drawn into the lungs, which can result in pneumonia. Do not force the horse’s head down. Instead, let him stand in a quiet area of the barn; bring in a companion if that will help. Monitor the situation Keep an eye on nasal drainage. In most cases of choke, backed-up grain will eventually start leaking from the nostrils. Wipe away the discharge with a clean rag and repeat every five minutes or…

▸ Definition: Technically called urticaria, hives are soft, distinct, raised skin wheals created when capillaries below the skin’s surface leak serum. Hives begin as small areas of swelling but may grow to merge into larger patches. ▸ Causes: Hives can be a reaction to a topical irritant, such as a bug bite, or a systemic response to food or medicine the horse has ingested. Reactions caused by topical irritants tend to be limited to one area of the horse, whereas systemically induced hives appear over the entire body. ▸ Signs: In addition to the appearance of wheals, hives may also cause itchiness, particularly in the earliest stages of the reaction. ▸ Treatment: Mild to moderate hives are typically treated by identifying the causative agent and eliminating it from the horse’s…

Just as with people, slimming down an overweight horse can be difficult, particularly one that’s genetically predisposed to heaviness. It’s much better to prevent obesity. This requires an unbiased eye and vigilant management, but the payoff for the health of your horse will be immense. Here’s how you can do it: 1. Count the calories in concentrates. Sweet feed and other concentrates provide essential calories to horses who need them---athletes, pregnant mares and the like. But they fuel weight gain in an easy keeper. Many horses don’t need any grain, yet receive a half scoop twice a day so they don’t feel left out at mealtime. This “kindness” only leads to obesity. If your horse is verging on being overweight, cut back his concentrates to a literal handful or none at…

▸ Immediately: Look for signs of injury. A small puncture wound or even a scratch can introduce bacteria under the skin, leading to an infection that causes massive swelling. Using your fingers to part the coat, look for breaks in the skin and feel for irregularities in the surface. Report your findings to the veterinarian. ▸ Immediately: Look for other swelling. A fat leg will command your attention, but check the horse’s other legs and midline for inflammation as well. If more than one leg is swollen, or if both hind legs are thick, the horse may have an extreme case of stocking up. However, swelling that extends up through his groin and midline could be the result of a systemic illness. ▸ Immediately: Take your horse’s temperature. A swollen…

▸ Definition: Laminitis is inflammation of the thin tissues (sensitive laminae) that anchor the coffin bone to the inside of the hoof wall. If enough fibers fail, the laminae lose their grip and the coffin bone drops away from the hoof wall and rotates or sinks downward, a condition called founder. ▸ Causes: Laminitis can be triggered by a variety of factors, including mechanical stress, such as galloping down a paved road; systemic illness or infection, particularly high fevers or a retained placenta in a mare; dramatic carbohydrate overload, such as a grain binge; metabolic disturbance from excessive grain or lush pasture in a predisposed horse; endocrine disorders like pituitary pars intermedia dysfunction (PPID, also known as Cushing’s disease). ▸ Signs: lameness, increased digital pulse, heat in the feet, reluctance…

▸ Signs: excessive tears, redness, squinting, repeated shaking of the head, cloudiness or swelling of the cornea or eyelids ▸ Causes: a foreign object, such as a splinter, in the eye or tear in the surface. Uveitis, swelling of the colored portion of the iris, and conjunctivitis, swelling of the membranes around the eye, can produce the same acute signs as an injury. ▸ Treatment: Some eye injuries require surgery. Others may heal with antibiotic ointment alone, but hourly, round-the-clock administration may be necessary. ▸ Prognosis: from full recovery to permanent loss of vision and even the eye itself, depending on the severity of the injury, the level of contamination and how quickly treatment begins…

bronchitis—inflammation of the bronchi (bronchial tubes). bronchodilator—agent that causes the air passages of the lungs to widen. capillaries—smallest of the blood vessels; connect arteries to veins. endotoxemia—presence of specific bacterial poisons (endotoxins) in the blood; usually caused by severe colic and resulting in shock and/or laminitis. enterolith (intestinal stone)—abnormal concretion that forms in the intestine; usually comprised of mineral salts, enteroliths resemble rounded stones. equine herpesvirus (EHV)—a family of viruses that primarily cause chronic respiratory infections in horses (EHV-1, EHV-4). EHV-1 can also cause abortions in mares and, in rare cases, both EHV-1 and -4 can cause neurological signs, including progressive weakness and in-coordination. EHV-3 causes a venereal disease called equine coital exanthema. guttural pouches—two sacs connected to the eustachian tube between the horse’s ear and throat, opening into the…