Hypercalcemia and calcinosis in Florida horses: implication of the shrub, Cestrum diurnum, as the causative agent.

This research focuses on a debilitating disease observed in Florida horses, mainly characterized by loss of weight, heightened lameness, and elevated plasma calcium levels. The study suggests that consumption of Cestrum diurnum, a shrub widely found in their grazing areas, is the primary cause of this disease.

Overall Disease Description

• The focus of the research is a chronic illness found in Florida horses that has a serious impact on their health, causing progressive weight loss and increasingly severe lameness.
• This disease is also connected with an abnormal increase in plasma calcium levels in the affected horses, described here as moderate to severe hypercalcemia.

Physical Changes in Affected Horses

• Anatomy of afflicted horses shows dystrophic calcinosis of elastic tissues, which essentially means abnormal calcium deposits found in major arteries, tendons and ligaments.
• A generalized osteopetrosis, a condition characterized by an increase in skeletal mass due to disrupted bone remodeling, is also evident in the affected horses.
• This osteopetrosis may be related to hypoparathyroidism, a condition resulting from underactive parathyroid glands, and hypercalcitoninism, an exceedingly high level of the hormone calcitonin in the blood.

Shrub as the Suspected Cause

• The study puts forward strong evidence linking the shrub Cestrum diurnum, also known as day-blooming jessamine, day cestrum, or wild jasmin, to the disease due to several observations.
• The shrub grows in areas accessible to the afflicted horses and the leaves of the plant in these areas were found to be stripped, suggesting that the horses had been eating them.
• Researchers discovered a potent, active, vitamin D-like substance in this plant. It is conjectured that the ingestion of this plant leads to the abnormalities in mineral metabolism observed in the affected horses.

Conclusion

• The research concludes that horses’ consumption of Cestrum diurnum, containing a potent vitamin D-like substance, might be causing this debilitating disease.
• Further study is implied to gain a better understanding of this disease’s process and the role of the shrub in causing the abnormalities.