Enostosis-like lesions in equids: 79 cases (1997-2009).

This research article is a retrospective case series study that investigated the conditions of horses (equids) with enostosis-like lesions (ELLs) over a period of 12 years. The study reviewed the records of 4,992 horses, identified 79 cases with ELLs, and documented the severity, location, breed vulnerability, and impact on racehorse performance.

Study Methodology

• The researchers conducted a retrospective case series study, focusing on horses diagnosed with enostosis-like lesions (ELLs).
• They poured through the medical records of 4,992 horses that had undergone bone scintigraphy—a non-invasive imaging method used to evaluate bone health—between March 1997 and March 2009.
• Of these, 78 horses and 1 pony were confirmed to have an ELL through scintigraphic diagnosis.
• The data collection included the horse’s breed, age, and gender; physical, lameness examination, scintigraphic, and radiographic results; and eventual outcome. Lameness is a clinical sign associated with pain or difficulty in locomotion.

Findings

• Out of the 79 horses, 4 had distinct ELLs in 2 to 4 separate instances, causing lameness in different limbs. This led to a total of 85 ELL-related admissions to the hospital.
• A total of 157 ELLs were detected throughout the study.
• Among the horses that underwent scintigraphic examination, the Thoroughbred breed was more commonly affected, while Standardbreds were less commonly affected.
• Older horses were found to be more susceptible to developing ELLs.
• Almost half of the admissions (42 out of 85) directly linked lameness to scintigraphically evident ELLs.
• The tibia (39.5%) and radius (29.3%) were the most common locations for ELLs.
• Horses with ELLs in the humerus experienced more severe lameness than those with ELLs in other locations.
• The intensity of radiopharmaceutical uptake, a measure of the severity of the condition, was associated with the severity of lameness.
• Among racehorses, those with a single ELL were more likely to return to racing than those with multiple ELLs identified in one scintigraphic examination. On average, these horses took about 184 days to return to racing after diagnosis.

Conclusion

• The study’s findings give a comprehensive view of ELL in horses, including vulnerability factors, lesion locations, associated symptoms, and impact on performance, particularly for racehorses.
• This retrospective evaluation provides important insights into ELLs in equids, offering a better understanding of the disease process which will assist in future clinical diagnosis and disease management.