Sour Horse Syndrome

Serenity streams from the old mare’s eyes. A pillar of patience, she stands in the crossties for hours as currycombs circle and dandy brushes flick her dark coat. Her long, wavy mane and tail, thick and resilient, have withstood thousands of brush strokes and impromptu braids. Over the years, her chestnuts have been tugged at and twisted; her hooves picked, poked, and prodded. Through it all, for nearly three decades, sound legs, broad loin, and steady, smooth gaits have provided a safe haven for beginner riders. Now, her muzzle silvered and her cheeks sunken, she is less saint and more shark under saddle. Stoic for saddling, cinching, and bridling, her demeanor changes as her charge mounts. Once alert and inquisitive, the mare’s ears swivel back, tense and annoyed through the entire ride. Her tail, which the old mare carried happily for years, now holds a kink and swishes spitefully. The mare’s lips purse at the subtlest of aids. What has caused this swap from sweet to sour?

The aforesaid scenario plays out the world over. As horse owners, we know that sourness eventually descends on many horses, not just elderly school horses or overtired show horses. Why do horses become sullen? What makes a pleasant companion turn into a crotchety, unpredictable source of pinned ears, wringing tail, and unwillingness?

One of the commonest explanations of sourness involves physical discomfort. A comprehensive examination by a veterinarian may help locate the source of pain. In the search for an origin of sourness, four potential points of interest deserve close scrutiny.

• Dental problems. Problems with teeth are often at the root of a changed personality. The roster of potential dental troubles is long: presence of wolf teeth that interfere with bitting; fractured or misshapen teeth; sharp points that can press into the cheek, making chewing and bit-carrying painful; loose teeth that contact the bit, creating a vibratory sensation; or other issues. As horses grow old, they may require more than an annual once-over, especially as teeth loosen in advance of falling out. Work with a competent dentist or a veterinarian with experience in treating dental disorders to ensure the mouth is healthy and sufficiently comfortable to carry a bit and chew normally.

• Tack suitability and fit. The weal and woe of a horse’s disposition under saddle or in harness often hinges on the comfort of the equipment chosen for him. An experienced saddle-fitter can fine-tune the fit of a saddle, taking into account the conformational contours of a horse or pony. Or, if the saddle is entirely unsuitable for a horse, the saddle-fitter can suggest an alternative, noting the features of a saddle that would complement the horse. Choosing an appropriate saddle often means selecting a model that defies current trends. Consider also that fit may change with variations in condition and muscling; a saddle that fit in previous years may no longer be suitable as fitness and condition changes. While saddle pads can alter saddle fit somewhat, they should not be relied upon to rectify significant deficiencies in fit. A sore mouth from an ill-fitting bit can cause sufficient irritation to trigger sourness. Look for signs of soreness, including small wounds at the corner of the mouth or redness of gums. Have a professional double-check the sizing and adjustment of any piece of tack that might be causing pain.

• Chronic lameness. Most horsemen can recognize the signs of moderate to severe lameness. Head-bobbing is a reliable indicator of lameness, as are shortening of stride, stiffness, reluctance to move, and unevenness of gait. Using flexion tests and other diagnostic procedures, a veterinarian can often isolate the location of the lameness and offer a plan to restore soundness. Veterinarians may find rooting out the cause of subtle or on-again, off-again lamenesses much more difficult. Low-level joint pain, as might be the case with arthritis, can cause resentment in horses. When considering the dietary needs of working horses, always err on the side of caution and choose to use nutritional supplements designed to support joints. For horses with a long working life ahead of them, it is advantageous to start joint supplements when horses first begin work under saddle or in harness. Choose high-quality supplements manufactured by a reputable company.

• Gastrointestinal discomfort. The gastrointestinal tract of the horse can be a source of multiple ails, some of which shift the disposition from cordial to crabby. Gastric ulcers are a familiar bother for high-performance horses, but all horses are susceptible to them, even those that lead inactive lives. Gastric ulcers have been implicated in all manner of crotchetiness, often materializing as pinned ears, uneasiness about grooming, girthiness, and an unwillingness under saddle. Horses thought to have hindgut acidosis share a similar rollcall of physical signs. Because of their seriousness, gastric ulcers and hindgut acidosis should be addressed by a veterinarian. Once gastric ulcers are cleared through the use of omeprazole, a research-proven gastric support supplement should be offered to the horse to buffer the gastric environment to keep new ulcers from forming. Hindgut acidosis can be resolved through the use of a hindgut buffer, such as EquiShure. Management strategies to prevent gastrointestinal problems include provision of forage for much of the day, concentrate meals no larger than 5 lb (2.2 kg), free-choice access to fresh water, and liberal turnout with companionship.

While sourness often stems from a physical problem, a psychological component may too be at play. A horse’s disagreeable behavior may arise from fear, frustration, fatigue, confusion, or boredom, all of which can cause low-level, sustained stress, ultimately culminating in irritability. When faced with a sour horse, look for reasons, both physical and psychological, that could be at the core of its crossness.