The nephrotoxic potential of neomycin in the horse.

This research examined how the medication neomycin, administered to adult horses, impacts their kidney function. Although some initial kidney damage was observed, no lasting functional toxicity was found, but it’s suggested that further monitoring is necessary particularly for unwell horses receiving this treatment.

Research Methodology

• The study was conducted on four healthy adult horses, which were given neomycin intramuscularly (injected directly into the muscles).
• This medication was given at a dose rate of 10 milligrams per kilogram of the horse’s bodyweight, every 12 hours for 10 days. This totaled up to 21 doses for each horse.
• Both the pharmacokinetic behaviour of neomycin and several clinical and urinary parameters were monitored during the course of the study. The pharmacokinetic behaviour relates to how the drug is absorbed, distributed, metabolized, and excreted in the horse’s body.

Findings

• The horses showed signs of physical renal tubular injury within four days of starting the neomycin treatment. This damage was evident through enzymuria (the presence of enzymes in the urine) and cylindriuria (the presence of urinary casts, an indicator of renal damage).
• Despite this initial indication of renal damage, the symptoms subsided after the treatment had ended, indicating that the kidney function returned to normal post-treatment.
• The study found no significant functional toxicity in the horses’ kidneys as a result of the neomycin treatment.

Recommendations and Implications

• While no serious damage was observed among the normal horses, the research suggests that more severe kidney damage might occur in ill horses subjected to the same neomycin treatment.
• Given this risk, the researchers recommend that clinicopathological results be monitored serially. Serial monitoring implies regular and repeated testing in those horses which are receiving parenteral neomycin (neomycin administered through non-oral means).
• This regular monitoring will help to identify any potential kidney damage as quickly as possible, thereby reducing the risk of lasting harm.