Osteopetrosis in two foals.

This research article discusses two cases of osteopetrosis in newborn foals. It provides a detailed observation of the condition, including symptoms and post-mortem examination findings, but does not definitively determine if the condition is hereditary in horses.

Osteopetrosis Condition in Foals

• The paper discusses two separate cases of neonatal foals affected by osteopetrosis. Osteopetrosis is a rare bone condition characterized by excessive densification of bone, affecting the bone marrow and making bones fragile. It can lead to various health problems like fractures, stunted growth, and other physical deformities.
• Of the two foals, one was a Peruvian Paso born full term. The foal was very alert but could not stand and was euthanized after two days. The other, an Appaloosa foal, was also born full term and was found to be blind, weak, uncoordinated, and unable to stand.

Postmortem Examination Findings

• The postmortem examination on both foals revealed generalized osteopetrosis and brachygnathia inferior, a condition in which there is abnormal shortness of the mandible (lower jaw).
• The osteopetrosis in these cases was specifically characterized by a failure of bone remodeling, resulting in spicules of mineralized and nonmineralized cartilage covered by immature bone tissue, known as osteoid, occupying the bone marrow areas of bones.

Possible Hereditary Nature and Comparison with Bovine Osteopetrosis

• The study does not conclusively determine whether osteopetrosis has a hereditary basis in horses but suggests that might be the case with the Peruvian horse, based on circumstantial evidence.
• The research paper then moves on to compare the osteopetrosis observed in these foals with previously reported cases in cattle. While the lesions are similar in both species, the severity is slightly less in horses.

Conclusion

• The research adds knowledge to the rare condition of osteopetrosis in horses, providing valuable data through postmortem examination findings and comparisons with the disease in cattle. Despite these insights, further research is needed to conclusively determine the hereditary nature of the disease in horses.