Ceftriaxone is a semi-synthetic third-generation cephalosporin antibiotic used in humans and animals (Reiner et al., 1980) and shows its antibacterial effect by disrupting the cell wall synthesis of bacteria.Ceftriaxone has a broad spectrum of action which covers gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella spp., and Salmonella spp.) and gram-positive (Staphylococcus aureus and Streptococcus pneumoniae) bacteria (Perry & Schentag, 2001). Ceftriaxone is widely used in the veterinary field due to its broad spectrum of action, long half-life, low toxicity, and resistance to β lactamases (Cleeland & Squires, 1984;Landesman et al., 1981). Ceftriaxone is recommended for use in respiratory, urogenital, and gastrointestinal tract infections as well as in skin and soft tissue infections, septicemia, and mastitis in sheep (Durna Corum et al., 2018). The antibacterial effect of ceftriaxone is time dependent, and time when the antibiotic concentration remains above the minimum inhibitory concentration (MIC) value (T > MIC) is used in the evaluation of its efficacy. T > MIC of 40%-70% for cephalosporins is