Marbofloxacin is a synthetic, bactericidal antimicrobial, belonging to the fluoroquinolone group which acts by inhibition of DNA gyrase. Fluoroquinolones act by concentration-dependent killing mechanism, so high plasma concentration initially is important (see below). It is effective against a wide range of Gram positive bacteria (in particular Staphylococci) and Gram negative bacteria (Escherichia coli, Salmonella typhimurium, Campylobacter jejunii, Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, Morganella morganii, Proteus spp, Klebsiella spp, Shigella spp, Actinobacillus pleuropneumoniae, Bordetella brochiseptica, Pasteurella haemolytica, Pasteurella multocida, Haemophilus spp, Moraxella spp, Pseudomonas spp, Brucella canis) as well as Mycoplasma (Mycoplasma bovis, Mycoplasma dispar, Mycoplasma hyopneumoniae). The bactericidal activity of marbofloxacin is concentration dependant on Gram–negative strains and time dependant on Gram-positive strains.

After oral administration to calves at the recommended dose of 1mg/kg, marbofloxacin is quite slowly absorbed and its bioavailability is close to 100%. It is weakly bound to plasma proteins (about 30% in calves), extensively distributed and in most tissues (liver, kidney, skin, lung, bladder, digestive tract) it achieves higher concentrations than in plasma.

After an oral administration, marbofloxacin is eliminated slowly in calves (t1/2β = 8.50 ± 2.88h) predominately in urine (72-81%) and faeces (5-13%) and in active form.