Safety of ceftiofur sodium administered intramuscularly in horses.

This study evaluates the safety of the antibiotic ceftiofur sodium in horses. It found the drug is generally well-tolerated even at high doses, but can cause decreased food consumption and mild skeletal muscle irritation at the injection sites.

Research Context

• The study aims to assess the safety of the antibiotic ceftiofur sodium when used in horses. Ceftiofur sodium is a broad-spectrum cephalosporin antibiotic that fights many different types of bacterial infections.
• The research is important because ensuring the safety of any medication used in animals is crucial, and specifically, knowing the side effects related to ceftiofur sodium in horses contributes valuable information in veterinary medicine.

Methodology

• Horses, both male and female, were split into groups. Some were given a saline solution as a control, while others were given different doses (2.2, 6.6, or 11 mg/kg/day) of ceftiofur sodium for 30 or 31 days.
• These dosages were expressed in terms of the free acid form of ceftiofur, representing 1 to 5 times the proposed therapeutic dosage.
• The researchers measured several types of data including clinical observation; physical examination; pelleted food consumption; body weight; hematologic, serum biochemical, and urinalysis findings; organ weight; gross necropsy observations; and histopathologic findings.
• Some horses were euthanized on days 31 or 32 for a necropsy, while others were observed for another 30 days before being euthanized and necropsied on day 60.

Findings

• Overall, ceftiofur sodium was found to be generally well-tolerated by the horses, even at exaggerated doses and treatment durations.
• However, a slight to mild decrease in food consumption was noted in horses given 6.6 or 11 mg of ceftiofur sodium/kg/day. This decrease in appetite started on the second day and lasted approximately 9 to 12 days.
• Additionally, a mild irritation in the skeletal muscles was detected through gross and microscopic examination of the injection sites in horses given the antibiotic. The prevalence and severity of the muscle irritation appeared to increase with higher concentrations of the dose.
• No other significant adverse effects were noted, indicating that Ceftiofur sodium is generally safe to use in horses, but caution is advised regarding possible appetite loss and muscle irritation.