Swayback, or equine lordosis, is characterized by a large dip in the spine of a horse, often resulting in a high wither and severe downwards curve to their topline.
Swayback is more common in older horses and broodmares who have carried multiple large babies. Lordosis can also occur in younger horses with a genetic predisposition. 
Equine lordosis is caused by a failure of the ligament support structures along the length of the back. When the ligaments are weak, stretched, or compromised, the spine can sag toward the ground.
Although shocking in appearance, equine lordosis does not usually mean a horse must be retired from all ridden work. With good management, these horses can remain sound and pain-free through their ridden career. 
Swayback horses require appropriate conditioning to strengthen their topline muscles. Special consideration must also be given to ensure proper saddle fit.
This podcast reviews the causes and management considerations for swayback horses.

Read more: https://madbarn.ca/swayback-horse/
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