Consequence of excess iodine supply in a Thoroughbred stud in southern Brazil.

The research paper explores the adverse effects of excessive iodine supply to Thoroughbred foals and mares in a stud in Brazil, with significant findings that high iodine intakes led to health issues including goitres and bone metabolism disorders.

Research Overview

• The study was conducted on a Thoroughbred stud in southern Brazil, where excess iodine was provided to the animals.
• It focused on observing the effects of the over-supply of iodine in both foals and expectant/lactating mares.

Key Findings

• The researchers found that excessive iodine supply, specifically intakes of at least 700 mg inorganic iodine in foals, and more than 350 mg iodine in pregnant and lactating mares, caused serious health problems.
• Goitres, an abnormal enlargement of the thyroid gland, occurred at a high rate in the newborn foals. This is an indication of higher iodine concentration, a condition which can interfere with the normal functioning of the thyroid.
• The foals also showed irregularities in their long leg bones, suggesting that high iodine intake can disrupt normal bone development and lead to skeletal issues.
• Increased levels of phosphorus and alkaline phosphatase in the blood were also noted, a sign of severe disturbance in the bone metabolism.
• Notably, out of 39 pregnant mares, 17 experienced abortions. Some of these mares also showed signs of goitre development.

Consequences and Remediation

• Upon detection of these adverse effects, the iodine supply was withdrawn from the mares’ diet. Following this, a gradual normalization of conditions took place.
• Foals born more than six weeks after the withdrawal of the iodine excess showed normal conditions, indicating recovery following the removal of excessive iodine supply.
• Goitres in the mares decreased in size and high iodine levels in their blood diminished, further indicating successful recovery after removal of the iodine over-supply.