Effect of primary and recurrent infections bovine rhinotracheitis virus infection on the bovine ovary
Miller, J.M.; Van Der Maaten, M.J.
American Journal of Veterinary Research 46(7): 1434-1437
1985
ISSN/ISBN: 0002-9645 PMID: 2992325 Document Number: 264989
Six heifers were inoculated i.v. at estrus with the Iowa or Colorado isolates of infectious bovine rhinotracheitis virus (IBRV). Subsequent measurements of plasma progesterone indicated that corpus luteum function was depressed in all heifers. In the 1st estrous cycle after inoculation, progesterone values did not exceed 2 ng/ml in 3 heifers given the Iowa isolate. Although maximal progesterone values were .gtoreq. 2 ng/ml in 3 heifers given the Colorado isolate, values were lower than those in later cycles. Five heifers had maximal diestrual progesterone values .gtoreq. 5 ng/ml within 5 wk after inoculation, but in the 6th heifer, this amount of progesterone was not present until 8 wk after inoculation. At 3-5 mo. after inoculation, all heifers were given 5 daily injections of dexamethasone, 2 heifers each during metestrus, diestrus, or proestrus. Subsequent recrudescence of IBRV was demonstrated in all heifers by the isolation of virus from vaginal or nasal swab samples. The heifers were killed 10-17 days after initiation of dexamethasone treatment and their reproductive organs were examined for lesions and IBRV. Lesions were not seen, and IBRV was isolated only from the corpus luteum of a heifer given dexamethasone during diestrus.