Pharmacokinetics of Oxytetracycline Following Intramuscular Administration in Yankasa Sheep in Kano State

Oxytetracycline remains one of the most widely used broad-spectrum antibiotics in veterinary medicine across Nigeria, particularly in treating bacterial infections in small ruminants. However, pharmacokinetic data specific to Yankasa sheep, a predominant breed in the North West geopolitical zone including Kano State, are lacking. This study determined the plasma pharmacokinetic profile of oxytetracycline following a single intramuscular injection of 20 mg/kg body weight in Yankasa sheep. Eight healthy adult rams were used in a non-crossover design, and serial blood samples were collected at 0, 0.5, 1, 2, 4, 6, 8, 12, 24, 36, and 48 hours post-administration. Plasma oxytetracycline concentrations were determined using high-performance liquid chromatography. A two-compartment open model was used to describe the concentration-time data. The maximum plasma concentration was 3.8 micrograms per millilitre achieved at 1.5 hours post-injection. The elimination half-life was 9.3 hours, and the area under the curve was 52.4 microgram-hour per millilitre. Volume of distribution was 1.2 litres per kilogram, indicating wide tissue distribution. These parameters suggest that dosing intervals of 24 hours may be adequate for treating most susceptible infections in this breed. The findings provide breed-specific pharmacokinetic data that can guide rational antibiotic use and improve treatment outcomes in Yankasa sheep in Kano and similar environments. Keywords: oxytetracycline, pharmacokinetics, Yankasa sheep, intramuscular, Kano.