Cushing's Disease And Swayback
Rapid development (over months) of a swaybacked appearance with a pendulous abdomen can be a symptom of Cushing's disease, a pituitary tumor common in older horses. The cause is overstimulation of the adrenal glands to produce the hormone cortisol. Cortisol interferes with the muscle cell's ability to utilize fuels, resulting in weakness and loss of muscle bulk.
Back Exercises
While there's not much you can do about overstretched ligaments, the muscles supporting the spine respond well to conditioning exercises. Before starting an exercise program, make sure the horse doesn't have any lameness issues behind that would interfere with his ability to engage his hindquarters and work well under himself.
Back exercises are best done from the ground, without the inhibiting effect and extra strain of a rider's weight. Anything that encourages the horse to work well under himself and in a rounded frame helps to strengthen the back. These include:
• Carrot stretches (see May 2004) and stroking along the midline of the belly with enough pressure to make the horse arch his back.
• Line driving, with good contact with the bit. Eventually, if the horse is up to it, this can progress to work with a light cart.
• Free longeing at an animated walk and controlled but energetic trot, as long as the horse drops his head enough to round the back and brings his hindquarters under him.
• Longeing with a harness and side reins adjusted so that they're not overly restrictive but are most comfortable when he lowers his head and flexes at the poll enough to slightly round and stretch his back. Again, a strong walk and engaged trot are best.
• Longeing over ground poles encourages the horse to drop his head and round his back
The goal is not to make the horse break a sweat and definitely not to cause any fatigue. Start slow, with things the horse tolerates easily, and gradually increase the difficulty.
Padding And Saddle Fit
Since lordosis is caused by a combination of gravity, weight and conformation, nothing you do in terms of saddle fit or padding is going to have much effect. However, because the support system of the back is weakened, make sure weight is being evenly distributed. Cut-back saddles usually work best because of the prominent withers.
Check saddle fit meticulously. Additional thick foam padding to help raise the position of the saddle to a more normal one is helpful. Always remember, though, that the rider's weight, and therefore the force it puts on the back, is the same regardless of how much padding you use. A swaybacked horse is a poor choice for a large rider.
Congenital Swayback
A small number of extremely young horses (less than 1 year old) may also develop lordosis. This may be a randomly occurring birth defect, or in the case of some Saddlebred lines, is likely to be genetic. The problem is caused by malformed vertebrae that are narrower at their base than normal, causing the bottoms of the vertebrae to line up in the dished, swayback configuration rather than as a straight spine. Young horses with this problem may also have scoliosis, a twisting of the spine out of its straight line configuration when viewed from the top.
