Animal Reproduction Science 101 (2007) 252–256 Early detection and treatment of vesicular adenitis in bulls Marcelo F. Mart´ ınez, Albert D. Barth * Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Sask., Canada S7N 5B4 Received 14 July 2006; accepted 5 September 2006 Available online 9 September 2006 Abstract The objective of this study was to determine whether early detection and treatment with tilmicosin would reduce the number of yearling bulls culled due to vesicular gland disease at the time of their first semen test. Bulls (n = 2207) of 15 breeds at 17 performance test stations were examined by transrectal palpation at 9–12 months of age and assigned to three treatment groups: (1) positive treated group, receiving subcutaneous injections of tilmicosin every second day for three treatments (2) positive untreated control group, (3) negative untreated control group. Transrectal palpation of the glands was done again at a pre-sale semen test 28–70 d (mean = 42.8 d) after the first examination. Semen was evaluated for the presence of pus and/or leukocytes by light microscopy. The proportion of bulls with vesiculitis was 4.4% (97/2207). At the pre-sale semen test the number of bulls with vesiculitis had decreased to 1.3% (29/2207); however, seven of these were new cases that developed after the first examination. Therefore, there was a recovery rate of 75/97 (77.3%) in the original group of bulls positive for vesiculitis. At the pre-sale test, there was no difference in the proportion of bulls with enlarged glands in the positive treated group (15/66) versus the positive untreated group (7/31) and no difference in the proportion of bulls with leukocytes or pus in their semen samples. The results of this experiment did not indicate any advantage in detection and treatment of vesiculitis before a year on age due to a high rate of spontaneous recovery. © 2006 Elsevier B.V. All rights reserved. Keywords: Vesicular adenitis; Yearling bulls; Antibiotic treatment; Tilmicosin * Corresponding author. Tel.: +1 306 966 7151; fax: +1 306 966 7159. E-mail address: albert.barth@usask.ca (A.D. Barth). 0378-4320/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.anireprosci.2006.09.009