Two experiments were designed to determine the efficacy of intraglandular
antibiotic treatment in beef bulls. Experiment 1 was designed to evaluate the glandular tissue reaction to intraglandular
antibiotic treatment. Experiment 2 was conducted to determine the efficacy intraglandular injection of
antibiotics for the treatment of naturally occurring cases of vesicular
adenitis. Healthy beef bulls (n=15), 2 and 3 years of age, were randomly allocated to three equal treatment groups to receive 10% of the daily recommended parenteral dose of
penicillin,
ceftiofur, or
oxytetracycline in a volume of 6 mL injected directly into one of the vesicular glands. Ultrasonography was performed before, immediately after, and at 24, 48 and 168 h after intraglandular injection. The size and hardness of vesicular glands injected with
oxytetracycline was greater (P<0.01) than those injected with
ceftiofur. Ultrasonographic pixel intensity increased (P<0.01)
after treatment with
antibiotics, especially
after treatment with
oxytetracycline or
penicillin. In Experiment 2, yearling beef bulls with clinical vesicular
adenitis (n=14) were referred to the Western College of Veterinary Medicine for treatment. Eight bulls had unilateral and six had bilateral vesicular
adenitis. The most common isolate was Arcanobacterium pyogenes. Corynebacterium pseudotuberculosis was isolated from one bull. Bulls were subjected to rectal palpation and ultrasonography of the vesicular glands, semen collection by electroejaculation, and intraglandular treatment with
ceftiofur (n=13) and if necessary, a second intraglandular treatment of
penicillin (n=6). One bull was treated only with an initial intraglandular injection of
penicillin. Bulls were evaluated once a week over 6 weeks by palpation of the glands, and evaluation of semen. All bulls recovered from vesicular
adenitis after 3-6 weeks. There was a difference in the amount of
pus (P=0.042), leukocytes (P<0.001) and blood (P=0.003) present in ejaculates from before treatment to 3 weeks
after treatment. Pixel intensities in ultrasonographic images of healthy or affected vesicular glands, whether treated or untreated, did not change over time. Intraglandular injection of
ceftiofur in yearling bulls via the ischiorectal fossa was effective for treating vesicular
adenitis.