In most developed nations horses are employed primarily in sport or leisure activities rather than strenuous labor, so it has become rather rare to see an advanced case of "sway back". (Also called: Lordosis).
Swayback occurs with animals that have been ridden a lot, carried heavily loads, or from multiple pregnancies. It may occur during pregnancy and can contribute to complications such as pre-pubic tendon rupture.
Sway back 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. However it is also possible for congenital lordosis to be present at birth.
Also known as: hollow back, lowback, saddle back, soft back.
The Role of Breed
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.
Swayback has also been found to be common in the modern Karakachan breed in Bulgaria. This trait was no common in the breed previously but is now typical to some extent in most individuals.
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 American Saddlebred, Halflinger, Thoroughbred, Quarter Horse, and mixed-breed foals.
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.
Lordosis can also occur in other species such as cattle and guinea pigs. It is often see as a sign of poor breeding in these animals as they are not subject to mechanical causes like riding or load carrying. In cattle it can also be caused by toxins sich as tree tobacco.
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- Plumlee, K. H., Holstege, D. M., Blanchard, P. C., Fiser, K. M., & Galey, F. D. (1993). Nicotiana glauca toxicosis of cattle. Journal of Veterinary Diagnostic Investigation, 5(3), 498-499.
- POPOVA, M., NIKOLOV, V., KRASTEV, N., & GRADEV, G. (2018). STUDIES OF THE EXTERIOR OF THE KARAKACHAN HORSE BREED. Bulgarian Journal of Agricultural Science, 24(2), 290-295.
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- Seyrek-Intas, K., Kumru, I. H., & Seyrek-Intas, D. (2011). Rupture of the prepubic tendon in a congenitally lordotic mare. Tierärztl Prax Großtiere, 39, 46-48.