[Moxidectin poisoning in a foal?].

The article discusses a case of moxidectin poisoning in a two-day-old foal. The foal was treated for symptoms like coma, hypothermia, bradycardia, and hypoventilation, among others. Despite bladder repair surgery, the foal succumbed due to mixed acidosis and early symptoms of sepsis.

About Moxidectin and Case Presentation

• The study documents a case of a 2-day-old foal that was diagnosed with central nervous depression following an overdose of moxidectin. Moxidectin is a type of medication that belongs to the milbemycin anthelmintics group. It works by stimulating the action of GABA (gamma-aminobutyric acid), a neurotransmitter that helps to regulate neuronal excitability.
• The foal in the study not only went into a coma but also developed serious hypothermia, bradycardia (slow heart rate), and hypoventilation (under breathing). The lack of urine voiding and a slight distension in the abdomen suggested a ruptured bladder.

Finding and Diagnosis

• The possibility of a bladder rupture was confirmed through a transabdominal ultrasound and clinical-pathologic parameters. The recurrent sound from the lower lung parts and the onset of gastric reflux suggested aspiration pneumonia.
• The researchers attributed the state of the foal to an overdose of moxidectin, explaining that the drug’s working mechanism via GABA could result in profound cases of central nervous depression, followed by hypothermia, bradycardia, hypoventilation, and paralytic ileus (a condition characterized by an obstruction of the intestines).
• The unexpected dyssynergia (an abnormality where muscles that usually work together do not) was deemed to be related to a central nerve problem rather than being a peripheral nerve issue.

Treatment and Outcome

• The foal underwent bladder repair surgery to correct the rupture. However, despite the surgical efforts, it eventually succumbed due to the development of a condition known as mixed acidosis and early signs of sepsis after the surgery.
• Acidosis is a condition in which there is too much acid in the body’s fluids, whereas sepsis is a severe infection that spreads in the bloodstream. Thus, the condition of the foal deteriorated rapidly after the operation, leading to its demise.