Pine oil toxicity in the horse: drug detection, residues and pathological changes.

The research article focuses on the acute toxicity effect of pine oil, a common disinfectant, when intravenously administered in horses. The study reveals that the primary cause of death is severe lung swelling or pulmonary edema.

Detection of Pine Oil and Alpha Terpineol

• The article begins by discussing the detection of pine oil and alpha Terpineol, a primary component of pine oil. To recover alpha Terpineol from equine tissues, the researchers used a chemical extraction process involving heptane.
• The detection of alpha Terpineol was completed using gas chromatography with two possible methods for detection: flame ionization detection or through the use of pentafluoropropionic anhydride derivatization and an electron capture detection technique.

Effects of Pine Oil Injection

• The researchers administered a dose of 0.1 ml/kg of pine oil intravenously to the horses. The outcome was immediate death due to a significant occurrence of pulmonary edema, which is a condition marked by fluid accumulation in the lungs, leading to acute respiratory failure.
• The amount of alpha-terpineol detected in the blood and tissue samples ranged between 150 and 300 parts per million (ppm).

Smaller Doses and Longer Term Observation

• When the horses were exposed to smaller doses of pine oil (0.033 ml/kg), they survived and were later euthanized up to 48 hours post-injection for further study.
• Alpha-terpineol became undetectable in the blood of one of the study animals after about 2 hours. There was also no detectable presence in the tissue samples collected after death.
• However, the surviving horses showed significant pathological changes primarily in their lungs, supporting the observation that the respiratory system is significantly impacted by the injection of pine oil.

Conclusion

• Based on their findings, the researchers conclude that when pine oil is injected intravenously in horses, it leads to serious lesions primarily affecting the respiratory tract. The cause of death, as per the research, is linked to the onset of acute pulmonary edema.