From Dog

Cloxacillin is a synthetic penicillin derivative, effective against a range of Gram-positive and some Gram-negative bacteria.

This drug has a weaker antibacterial activity than benzylpenicillin, and is devoid of serious toxicity except for allergic reactions[1].

Antimicrobial susceptibilities, particularly with Staphylococcus aureus and Staphylococcus intermedius varies with regard to the site of isolation, sex and age of the dog[2].

Large numbers of genitourinary bacteria have now developed resistance to this drug, including Serratia spp, Acinobacter spp, Citrobacter spp, Klebsiella spp, Escherichia coli and Enterobacter spp[3].

Recommended dose rate is 20 - 40 mg/kg given orally, intramuscularly or intravenously every 4 - 8 hours.


  1. Lawrence SL et al (2005) Cloxacillin versus vancomycin for presumed late-onset sepsis in the Neonatal Intensive Care Unit and the impact upon outcome of coagulase negative staphylococcal bacteremia: a retrospective cohort study. BMC Pediatr 5:49
  2. Hoekstra KA & Paulton RJ (2002) Clinical prevalence and antimicrobial susceptibility of Staphylococcus aureus and Staph. intermedius in dogs. J Appl Microbiol 93(3):406-413
  3. Lobetti RG et al (2002) Bacterial colonization of intravenous catheters in young dogs suspected to have parvoviral enteritis. J Am Vet Med Assoc 220(9):1321-1324