by Leigh Ann Matthews
We’ve probably all seen a swaybacked horse at some point, either real or in cartoons, and wondered what might have caused the condition. Characterized by a large dip in the spine, often with very high withers and a downward curve to the topline and hip, equine lordosis, or swayback, is rare, occurring in less than 1 percent of the general horse population.
Lordosis is caused by a “failure of the ligament support structures” along the back. It is most common in older horses and broodmares but can also occur in younger horses with a genetic predisposition. The tendency to develop the condition seems to be more common among American saddlebred horses, but it can occur in any horse.
In some cases, the repeated additional weight of broodmares carrying foals can cause ligaments in the back to stretch, allowing the spine to sag. Ligaments in geldings, stallions, and nonbearing mares can also stretch. Muscles become weak along the topline, and the back begins to drop. The severity of the dropped topline depends on several factors. Equine lordosis
is rarely caused by injury, lack of care or proper nutrition, or serious conformation deformity.
Extensive research for equine lordosis has not been in the forefront, most likely because of its rare occurrence.
According to the Parelli Natural Horsemanship program, researchers say swayback “is rooted in genetics as a recessive gene that both the sire and dam must carry.”
As a graduate student at the University of Kentucky, Patrick Gallagher, Ph.D., studied the condition and also found a major genetic component. He concluded, “For the trait to surface in an individual, both sire and dam would have to contribute the lordotic gene(s). If only one parent contributed the recessive trait, the dominant gene in the pair would prevail and the spine would develop normally.”
The specific gene or genes involved have not been identified, so no current DNA test is available to screen for the characteristic. In-depth pedigree analyses and studies have not been done, so breeders should be cautious when selecting breeding pairs if the condition has occurred in offspring from either parent.
Alleviate Pain
Swaybacked horses generally do not exhibit signs of the condition being painful, and most of the animals function normally. Big concerns for horses with abnormal spine curvature are saddle fit and back injury. Many horses with lordosis might be relieved from strenuous work and riding, simply because of the difficulty of fitting them properly with saddles. Extra pads help, but horses with the condition can develop sore spots or painful areas from ill-fitting tack along the topline.
If you are using a horse that has a moderate dip, remember that the back will continue to change. Check the saddle fit frequently to ensure that the horse is not enduring unnecessary pain.
Gallagher offered a simple way to measure the dip. Mark the high point of the withers and the high point of the rump with adhesive tape. Measure the straight-line distance and the back-surface distance between the two points. The difference between the two points is the back-contour measurement. In his study, Gallagher found that the abnormality starts with contour measurements of 2½ to 2¾ inches, with the normal range being 1½ to 2 inches.
Provide Exercise
Specific exercises and physical therapy can improve lordosis by strengthening the muscles along the back and increasing the horse’s ease of movement. Parelli Natural Horsemanship suggests the following:
Stretches: Start with lateral bowing and extension exercises for durations of 10 to 15 seconds, adding time as the horse gets better at them.
Ground driving: Use ground driving as a nonriding method to encourage the horse to engage his core and hindquarters, lifting his back to strengthen abdominal and back muscles.
Cavalatti and pole work: Obstacles such as cavaletti and poles make the horse lift his hindquarters and core muscles and help him engage his core while carrying himself.
Weight management: The condition will be prone to worsen if the horse adds more weight. If the horse seems to grow a large “pasture belly,” check with your veterinarian to rule out Cushing’s disease.
Other techniques are surfacing as treatments for horses with lordosis, such as animal neuromyofascial release (ANMR), a body-alignment technique using soft-tissue mobilization.
Parelli adds, “Lordosis is not a diagnosis that has to stop your horse’s life. By staying active and engaged and [by practicing] harmonious riding with proper saddle fit, the horse can enjoy as many joy-filled years with you as a horse without swayback.”
As always, consult your veterinarian for diagnosis and treatment and to ensure confidence that your horse is sound for riding and other activities.
