Experimental study on blood gases and acid-base parameter changes following oral administration of injectable enrofloxacin 5 % to the horses

The objective of this investigation was to evaluate the effects of oral administration of bovine injectable enrofloxacin 5 % on blood gases, acid–base parameters, risk of gastrointestinal ulcers, bleeding, diarrhea, abdominal pain, and clinical joint disturbances in horses. For this purpose, there were nine selected mixed breed horses with ages between 11 month and 15 years old. These horses were divided into three groups of three animals. Bovine injectable enrofloxacin 5 % was administered orally, 5 mg/kg to the first group and 15 mg/kg to the second group, every 12 h, for 21 days. The third or control group did not receive drug but saline in the same way. Heparinized blood samples were collected for evaluation of blood electrolytes and blood gas parameters as well as recording the clinical findings in animals. Occult blood test was performed in all horse stool samples, in five times, before and after the administration of the drug. As a result, the analyzed data did not show significant changes in blood gases and electrolyte parameters, between drug-administered and control groups. There were no observed mucosal ulcer, injury or symptoms of diarrhea, abdominal pain, and gastrointestinal bleeding in the horses. One of the horses showed swollen in the left carpal joint with a dose of 5 mg/kg of drug, at day 12, which improved with suitable treatment until day 20. This study showed that 3 weeks of oral administration of enrofloxacin 5 % had no significant effect on blood gases and electrolyte parameters even at high doses (15 mg/kg). This study showed the lack of drug effect on producing gastrointestinal mucosal ulcers and colic pain in the drug-treated horses. It was recommended that the drug enrofloxacin should not preferably be used in foals and also in mature horses for long duration, because of the possible joint disorder, and its usage should be with caution.