Efficacy of a long-acting formulation of ceftiofur crystalline-free acid for the treatment of naturally occurring infectious bovine keratoconjunctivitis.

OBJECTIVE: To evaluate the efficacy of ceftiofur crystalline-free acid (CCFA) administered into the posterior aspect of an ear for treatment of corneal ulceration associated with naturally occurring infectious bovine keratoconjunctivitis (IBK). ANIMALS: 78 beef calves located at Sierra Foothills Field Station (SFS) and 52 calves located at a commercial dairy (CD). All calves were from 3 to 9 months old. PROCEDURE: At each site, calves were randomly allocated to 1 of 2 treatment groups by use of a block design determined by corneal ulcer size. A single dose of CCFA (6.6 mg of ceftiofur equivalents/kg, s.c.) was administered into the posterior aspect of a pinna. A second group of calves received a single dose of vehicle (0.03 mL/kg, s.c.; controls). Corneal ulcers were photographed, and clinical signs were assessed in calves every 3 to 4 days for 21 days. RESULTS: A positive treatment effect was detected at SFS. Results at the CD were inconclusive because ulcer healing occurred rapidly in control and CCFA-treated calves. At SFS, treatment with CCFA resulted in shorter mean healing times, smaller corneal ulcer surface area measurements, amelioration of ocular discharge and photophobia, and a 50% increase in the percentage of calves healed by day 14. After adjustment for initial corneal ulcer size, treatment with CCFA resulted in a 4-fold increase in the odds of corneal ulcer healing by day 14, compared with controls. CONCLUSIONS AND CLINICAL RELEVANCE: A single dose of CCFA administered into the posterior aspect of a pinna had a positive treatment effect against naturally occurring IBK in calves with corneal ulcerations.

Efficacy of ceftiofur for treatment of experimental salmonellosis in neonatal calves.

OBJECTIVE: To evaluate therapeutic efficacy of a high extralabel dose of ceftiofur for treatment of experimental salmonellosis in neonatal calves. ANIMALS: Forty-two 1- to 4-day-old Holstein bull calves. PROCEDURE: 36 calves were orally challenged with Salmonella enteritica serovar Typhimurium (6.5 x 10(8) colony-forming units). Six additional calves were retained as nonmedicated nonchallenged control calves. Four days following Salmonella challenge, surviving calves were randomly allocated to ceftiofur-treated (5 mg/kg, IM, q 24 h) or nonmedicated control groups. Calves assigned to the treated group were medicated daily for 5 days starting on day 4 after challenge. Calves were monitored for 18 days following Salmonella challenge. Outcome assessments included clinical parameters (attitude, appetite, fecal characteristics, and rectal temperature), mortality rate, and quantitative Salmonella culture of fecal samples, mesenteric lymph nodes, and cecal contents. RESULTS: Ceftiofur treatment was associated with a significant decrease in rectal temperature and diarrhea. Three of 15 medicated calves and 4 of 14 non-medicated calves died or were euthanatized between days 4 and 18. A significant decrease in fecal shedding of Salmonella organisms was observed in treated calves, compared with nonmedicated calves. Salmonella organisms were isolated from all 10 non-medicated calves at necropsy, whereas no Salmonella organisms were isolated from 5 of 12 medicated calves. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment of salmonellosis in neonatal calves with a high extralabel dose of ceftiofur (5 mg/kg, IM, q 24 h) promotes animal welfare, reduces fecal shedding of Salmonella organisms, and may promote clearance of Salmonella infections when plasma ceftiofur concentrations are maintained above minimal inhibitory concentrations.