Most horses are now employed in sport or leisure activities rather than strenuous labor, so it has become rather rare to see an advanced case of "sway back"
Swayback occurs with animals that have been ridden a lot, carried heavily loads or from multiple pregnancies. It is more likely to develop in horses with a long back and high head carriage and may be exacerbated by diseases like Cushings. Advanced cases are typically quite elderly animals.
Also known as: hollow back, lordosis, lowback, saddle back, soft back.
Saddlebred horses seem to be more prone to lordosis. Around 7% of American Saddlebreds will exhibit swayback, compared to around 1% in other breeds. They also tend to show this condition at an earlier age. The particular gene or genes responsible for this condition in Saddlebreds have not been identified.
Essentially the soft tissues have stretched and relaxed allowing a spinal deformity that can look quite alarming. however in most cases the animal is functioning quite normally and not in distress. Swayback in young horses is more likely to reflect poor breeding, overly severe use or over-training.
In a small number of cases foals are born already exhibiting swayback. These cases are consider likely to have a genetic cause, possibly via a recessive trait. As such they are more likely to occur pedigree lines with a high degree of inbreeding.
Examples have been described in the Halflinger and quarter horse.
Swayback may also occur as a consequence of another disease process, such as the lung disease silicosis.
Use of Saddle Pads
If a swaybacked horse is still suitable for riding a good saddle fit should be assured by using a saddle pad.