Effects of polymyxin B on selected features of equine carbohydrate overload.

This study investigates the effects of the antibiotic polymyxin B on horses experiencing carbohydrate overload, which is detrimental to their health. While it was believed that the drug may alleviate the negative effects of this condition, the results indicate that it does not significantly help with related issues such as increased blood clotting, acidosis, lameness and shock.

Carbohydrate Overload in Horses

• Horses and ponies can suffer from a condition called carbohydrate overload when they consume an excessive amount of carbohydrates.
• This syndrome is characterized by lactic acidosis (buildup of lactic acid in the body), hypercoagulability (the blood’s tendency to clot excessively), hypovolemic shock (a life-threatening condition caused by severe fluid loss), and lameness.
• Endotoxins, which are harmful substances produced by certain bacteria, are believed to contribute to this syndrome. In particular, gram-negative endotoxins have been implicated in carbohydrate overload.

Use of Polymyxin B to Treat Carbohydrate Overload

• Polymyxin B is an antibiotic that has been shown to have anti-endotoxin properties. Specifically, it can modify the lipid A part of the endotoxin, which is the active component, thereby neutralizing its effect.
• Given its anti-endotoxin properties, it was hypothesized that polymyxin B could potentially be used to treat carbohydrate overload in horses.

Results of the Study

• However, the results of this study indicate that polymyxin B has little effect on the symptoms of carbohydrate overload.
• Polymyxin B was administered intravenously at a dose of 2.5 mg/kg every 6 hours to the horses subjected to carbohydrate overload.
• Although the onset of clinical signs was slightly delayed in animals that were treated with polymyxin B, the drug failed to significantly reduce the severity of any of the symptoms associated with carbohydrate overload.
• In particular, there were no significant improvements in coagulopathy (blood clotting problems), acidosis (too much acid in the body), lameness (difficulty or inability to walk), or shock (acute circulatory failure).

Concluding Remarks

• The findings suggest that, despite its anti-endotoxin effects, polymyxin B may not be a suitable treatment for carbohydrate overload in horses.
• Further research may be necessary to identify other potential treatments for this condition.