Equine rib fractures can be challenging to diagnose and often result in poor performance. Certain equestrian sports, like steeplechase and polo, put horses at risk of falling, which can cause traumatic injuries. Even horses that don’t compete might fight in the paddock, and a well-placed kick can result in a rib fracture.
The large thoracic frame of a well-muscled horse can mask signs of a rib fracture. Not only is it difficult to see an abnormal contour of a rib, but dense muscling can reduce palpation pressure such that a horse won’t consistently exhibit a pain response. Some affected horses with rib pain might show lameness or display a gait deficit of forelimb abduction during limb protraction. Researchers in the U.K. examined the diagnosis, treatment, and outcome of rib fractures in horses at three referral hospitals over 15 years in a retrospective study.
Study Population
The study included 73 horses of various breeds engaged in racing, eventing, show jumping, dressage, pleasure, and general purpose equestrian pursuits. Horses were brought for veterinary examination due to owner complaints about the horse resisting ridden work and/or performing poorly; 57% of these had a rib fracture. Seven horses had a history of a known traumatic event, including a rotational fall, a trailer accident, or being hit with a hoof rasp. One horse had possibly been cast.
Lameness was apparent in 47 (64%) horses ranging from Grades 1-6 on a scale of 10. Only 21 horses had originally been brought to the veterinarian because of a lameness concern; the rest had an undetected low-grade lameness or lameness that did not concern the owner. Palpation localized pain at the rib fracture site in 47 horses, which was later confirmed with imaging. A common location of rib fracture was at T1/first rib, and those horses tended to be forelimb lame with a positive pain response with extension of the shoulder (protraction) on the side of the fracture. The 18th rib was the most affected in 31 (42%) of the horses. Saddle pressure at this location potentially stimulates more pain and subsequent behavioral problems when ridden than rib fractures in other sites. Other fracture sites in this study included ribs 17, 15, 13, 12, 10, 9, 8, 7, 6, and 5. Multiple ribs were affected in nine horses.
Equine Rib Fracture Imaging Results
The imaging results yielded the following information:
- Of 24 horses undergoing radiographic exam, 10 horses had a confirmed rib fracture diagnosis, with best image visibility using a laterodorsal-lateroventral oblique (skyline) view.
- Of 59 horses undergoing ultrasound examination, 58 (98%) were confirmed positive for rib fracture.
- Of 59 horses undergoing nuclear scintigraphy, all had a confirmed diagnosis.
Treatment and Outcomes for Equine Rib Fractures
Conservative treatment was opted for in all cases of non-displaced rib fractures, which included rest for 0-12 months. Six horses did not respond to conservative management and were taken to surgery. Seven horses returned to racing. Researchers followed 55 horses’ outcomes for more than a year: 28 returned to previous exercise level; 12 did not because of lameness not associated with the rib fracture; eight did not due to reasons unrelated to the rib fracture; and seven were euthanized, three of which as a consequence of the rib fracture. The location of the rib fracture made no statistical difference in whether a horse did or did not return to its previous exercise level.
Final Thoughts
In summary, the authors wrote: “Rib fractures should be considered in cases of ridden discomfort and poor performance and have a fair prognosis for return to athletic use.” Scintigraphy is an excellent tool for diagnosis, as is ultrasound examination, especially in cases where palpation does not clearly detect the fracture location.
Reference
Hall S, Smith R, Ramzan PHL, et al. Rib fractures in adult horses as a cause of poor performance; diagnosis, treatment and outcome in 73 horses. Equine Veterinary Journal 2022; DOI: 10.1111/evj.13566
Related Reading
- Ventral Interbody Fusion for Horses With C7-T1 Pathology
- Managing Lumbosacroiliac Joint Region Pain in Horses
- Using Advanced Imaging for Lameness Workups
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