Search Results

Abstract

Objective—To compare the efficacy of a Salmonella bacterin and a modified live Salmonella ser. Choleraesuis vaccine on a commercial dairy.

Animals—450 cows in late gestation and 80 calves.

Procedure—Group-1 cows (n = 150) were vaccinated once with a modified live S Choleraesuis (serogroup C1) strain 54 (SC54) vaccine, group-2 cows (150) were vaccinated on enrollment and 30 days later with a Salmonella ser. Montevideo (serogroup C1) bacterin, and group-3 cows (150) served as unvaccinated controls. One gallon of colostrum harvested from the first 80 cows to calve was fed to each calf. Outcome assessments included fecal shedding of Salmonella spp for the first 10 days after parturition (cows) or birth (calves), milk production, involuntary culling rate, mastitis incidence, antimicrobial use, and mortality rate.

Results—Salmonellae were isolated from 306 of 309 (99%) cows and 64 of 74 (86.5%) calves. Shedding frequency was less in SC54-vaccinated cows and calves that received colostrum from those cows, compared with the other groups, and vaccination was specifically associated with less shedding of serogroup C1 salmonellae. Production data were similar among groups.

Conclusions and Clinical Relevance—Vaccination of pregnant cows with an autogenous Salmonella bacterin had no effect on fecal shedding of salmonellae, whereas vaccination with a modified live S Choleraesuis vaccine reduced the frequency of fecal shedding of serogroup C1 salmonellae during the peripartum period. A commercial S Choleraesuis vaccine licensed for use in swine may be more efficacious than autogenous Salmonella bacterins on dairies infected with serogroup C1 salmonellae. (Am J Vet Res 2001;62:1897–1902)

Abstract

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, SC) was administered into the posterior aspect of a pinna. A second group of calves received a single dose of vehicle (0.03 mL/kg, SC; 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 . (Am J Vet Res 2004;65:1185–1188)

Abstract

Objective—To determine the efficacy of florfenicol for treatment of calves with naturally occurring infectious bovine keratoconjunctivitis (IBK).

Design—Randomized controlled field trial.

Animals—63 beef calves and 80 dairy calves between 4 and 12 months of age.

Procedure—Calves were randomly assigned to 1 of 3 treatment groups. Calves in the SC treatment group received a single dose of florfenicol (40 mg/kg [18.2 mg/lb] of body weight), SC, on day 0. Calves in the IM treatment group received florfenicol (20 mg/kg [9.1 mg/lb]), IM, on days 0 and 2. Calves in the control group received injections of saline solution (0.9% NaCl), IM, on days 0 and 2. Calves were reevaluated every other day for 20 days after treatment.

Results—Corneal ulcers healed by day 20 in 48 of 49 (98%) calves treated with florfenicol IM, 39 of 42 (93%) calves treated with florfenicol SC, and 33 of 52 (63%) control calves.

Conclusions and Clinical Relevance—Florfenicol administered SC (1 dose) or IM (2 doses 48 hours apart) was effective for treatment of calves with naturally occurring IBK. ( J Am Vet Med Assoc 2000;216: 62–64)