title: Efficacy of a Parapoxvirus ovis-based immunomodulator against equine herpesvirus type 1 and Streptococcus equi equi infections in horses.
abstract: The efficacy of Zylexis®, an immunomodulator in horses based on inactivated Parapoxvirus ovis (iPPVO), was assessed using an equine herpesvirus type 1 (EHV-1) challenge model in the presence of a natural infection with Streptococcus equi equi (S. equi). Eleven horses were treated with iPPVO and twelve were kept as controls. Six horses were challenged with EHV-1 and commingled with the horses on study. Animals were dosed on Days -2, 0 (just before commingling) and Day 7. On Day 11 significantly less nasal discharge, enlarged lymph nodes, EHV-1 shedding and lower rectal temperatures were observed in the iPPVO-treated group. In addition, iPPVO-treated horses showed significantly fewer enlarged lymph nodes on Days 17 and 19, significantly less lower jaw swelling on Day 3 and significantly lower rectal temperatures on Days 12 and 13. Dyspnoea, depression and anorexia were only recorded for the control group. Following challenge seven out of 11 horses in the iPPVO treated group shed EHV-1 but on Days 11, 12, 13, 14, 15 and 16 quantitative virus detection in this group was significantly lower as compared to the controls. All animals shed S. equi but the percentage of animals with positive bacterial detection was lower in the iPPVO group than in the control group from Day 14 through Day 28. This difference was significant on Day 24. No injection site reactions or adverse events were observed. In conclusion, Zylexis administration is safe and reduced clinical signs and shedding related to both EHV-1 and S. equi infections.
authors.affiliation: Zoetis Belgium S.A., Mercuriusstraat 20, B-1930 Zaventem, Belgium. Electronic address: Ellen.ons@zoetis.com.
authors.forename: Ellen
authors.initials: E
authors.lastname: Ons
authors.affiliation: Zoetis Belgium S.A., Mercuriusstraat 20, B-1930 Zaventem, Belgium.
authors.forename: Leen
authors.initials: L
authors.lastname: Van Brussel
authors.affiliation: ADAS UK Ltd., Alcester Road, Stratford-on-Avon, Warwickshire CV37 9RQ, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lane
authors.affiliation: Zoetis, 333 Portage Street, Kalamazoo, MI 49007, USA.
authors.forename: Vickie
authors.initials: V
authors.lastname: King
authors.affiliation: Irish Equine Centre, Johnstown, Naas, County Kildare, Ireland.
authors.forename: Ann
authors.initials: A
authors.lastname: Cullinane
authors.affiliation: Irish Equine Centre, Johnstown, Naas, County Kildare, Ireland.
authors.forename: Rachel
authors.initials: R
authors.lastname: Kenna
authors.affiliation: Irish Equine Centre, Johnstown, Naas, County Kildare, Ireland.
authors.forename: Pamela
authors.initials: P
authors.lastname: Lyons
authors.affiliation: Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, United Kingdom.
authors.forename: Toni-Ann
authors.initials: TA
authors.lastname: Hammond
authors.affiliation: Zoetis Belgium S.A., Mercuriusstraat 20, B-1930 Zaventem, Belgium.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Salt
authors.affiliation: Zoetis Belgium S.A., Mercuriusstraat 20, B-1930 Zaventem, Belgium.
authors.forename: Rudiger
authors.initials: R
authors.lastname: Raue
mesh_terms: D000818:Animals; D006566:Herpesviridae Infections / Q000188:drug therapy / Q000662:veterinary*; D004861:Herpesvirus 1, Equid / Q000276:immunology*; D006734:Horse Diseases / Q000188:drug therapy* / Q000382:microbiology* / Q000821:virology; D006736:Horses; D007155:Immunologic Factors / Q000235:genetics / Q000627:therapeutic use*; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D018157:Parapoxvirus / Q000235:genetics; D013290:Streptococcal Infections / Q000188:drug therapy / Q000662:veterinary*; D018502:Streptococcus equi / Q000276:immunology*; D017201:Virus Shedding / Q000187:drug effects
chemical_list: D007155:Immunologic Factors
keywords: Equine herpesvirus type 1; Immunomodulator; Parapoxvirus ovis D1701; Strangles; Streptococcus equi equi; Zylexis