Ceftiofur is an antibiotic of the cephalosporin type (third generation), licensed for use in veterinary medicine.

[3] It is marketed by pharmaceutical company Zoetis as Excenel,[4] Naxcel, and Excede and is also the active ingredient in that company's Spectramast LC (lactating cow formulation) and Spectramast DC (dry cow formulation) product.

[citation needed] It is resistant to the antibiotic resistance enzyme beta-lactamase, and has activity against both Gram-positive and Gram-negative bacteria.

Escherichia coli strains resistant to ceftiofur have been reported.

[5] The metabolite desfuroylceftiofur also has antibiotic activity.