title: Uterine infection with bovine herpesvirus type 4 in dairy cows.
abstract: Diseases of the reproductive tract are a frequent problem in dairy herds. Herpesviruses are uterine pathogens also involved in other clinical diseases; for example, bovine herpesvirus type 4 BoHV-4 induces abortion, enteritis, metritis, pneumonia and vaginitis, but it can also be detected in healthy cows. The role of BoHV-4 in the development of clinical endometritis (CE) or subclinical endometritis (SE) has not clearly been described. Therefore, the objective of this study was to describe the prevalence of uterine BoHV-4 infection and its relationship with clinical, bacteriological and cytological findings in dairy cows 20-30 days after calving. The experiment was performed as a completely randomized block design, with farm (n = 10) as blocking criterion and with cow (n = 397) as the experimental unit. Logistic regression models were used to assess the effect of BoHV-4 infection on CE, SE and reproductive performance. Proportion of cows infected with BoHV-4 was 5.8% (n = 23/397). BoHV-4 was isolated in 11.0% (n = 12/109), 4.8% (n = 4/84) and 3.6% (n = 7/194) of cows diagnosed as CE, SE or healthy, respectively. A logistic model revealed that BoHV-4 infection showed a tendency to increase the risk for CE (AOR = 2.17; p = .10) but significantly reduced both, the odds for artificial insemination within 80 days post-partum (dpp) (AOR = 0.37; p = .035) and for pregnancy within 200 dpp (AOR = 0.13; p = .004). Furthermore, BoHV-4 infection increased the chance for intrauterine infection with Trueperella pyogenes (AOR = 5.55; p < .001) and vice versa (AOR = 5.79, p < .001). In conclusion, BoHV-4 infection is associated with reduced chances for insemination and pregnancy by 200 dpp and showed a trend to be associated with increased risk for CE. Furthermore, BoHV-4 and Trueperella pyogenes infections are strongly related.
authors.affiliation: Vetmeduni Vienna, Department for Farm Animals and Veterinary Public Health, University Clinic for Ruminants, Clinical Unit for Herd Health Management, Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Klamminger
authors.affiliation: Vetmeduni Vienna, Department for Farm Animals and Veterinary Public Health, University Clinic for Ruminants, Clinical Unit for Herd Health Management, Vienna, Austria.
authors.forename: I
authors.initials: I
authors.lastname: Prunner
authors.affiliation: Cátedra de Fisiología, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, La Plata, Argentina.
authors.forename: M J
authors.initials: MJ
authors.lastname: Giuliodori
authors.affiliation: Vetmeduni Vienna, Department for Farm Animals and Veterinary Public Health, University Clinic for Ruminants, Clinical Unit for Herd Health Management, Vienna, Austria.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-2824-8185
authors.initials: M
authors.lastname: Drillich
mesh_terms: D000034:Abortion, Veterinary / Q000209:etiology; D000192:Actinomycetales / Q000302:isolation & purification; D000193:Actinomycetales Infections / Q000453:epidemiology / Q000662:veterinary; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000821:virology; D005260:Female; D006566:Herpesviridae Infections / Q000453:epidemiology / Q000662:veterinary*; D026021:Herpesvirus 4, Bovine / Q000302:isolation & purification*; D007315:Insemination, Artificial; D016015:Logistic Models; D011247:Pregnancy; D018873:Pregnancy Rate; D011897:Random Allocation; D012098:Reproduction; D012621:Seasons; D014412:Tumor Virus Infections / Q000453:epidemiology / Q000662:veterinary*; D014591:Uterine Diseases / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology