Trema micrantha toxicity in horses in Brazil.

The research presents a study of Trema micrantha poisoning in horses, showcasing symptoms like blindness, coma, and observed physiological changes like liver damage and cerebral oedema. The study suggests considering T. micrantha poisoning as a potential cause in cases of equine liver damage and occasional secondary encephalopathy.

Observation of Symptoms

The research began with the observation of two horses that showed symptoms after consuming green leaves of Trema Micrantha, a species of flowering tree common in Brazil. Symptoms included:

• Apathy or indifference
• Locomotor deficit, which can be understood as difficulty in movement or paralysis
• Blindness
• Recumbency, the inability to rise
• Paddling, a frantic and uncoordinated movement of the limb as if swimming
• Coma, a state of deep unconsciousness
• Death

Physiological Findings

On examination, the horses presented a variety of gross findings and histological changes. These included:

• Scattered hemorrhages
• An enhanced lobular pattern of the liver, suggesting liver damage
• Cerebral oedema, or swelling in the brain
• Disseminated hemorrhages
• Massive hepatocellular necrosis, or death of liver cells
• Neuronal degeneration
• Alzheimer type II astrocytes, which refers to a change in the appearance of certain cells in the brain
• Cerebral perivascular oedema, or swelling around the blood vessels in the brain

Significance of Findings / Conclusion

Based on the clinicopathological findings, the researchers concluded that the symptoms and physical changes were similar to those seen in Trema Micrantha poisoned ruminants, or animals that chew the cud. This, together with epidemiological evidence, suggested Trema Micrantha poisoning as the diagnosis for these symptoms and physical changes.
The authors of the study advise that Trema Micrantha poisoning should be evaluated as a possible cause during diagnoses of equine hepatopathy, a disease affecting the liver of horses, and with occasional secondary encephalopathy, which is a disorder resulting from a disease that affects the brain.