title: Impact of Giardia vaccination on asymptomatic Giardia infections in dogs at a research facility.
abstract: Feces were collected from 107 asymptomatic dogs at a research facility in Guelph, Ontario. The prevalence of Giardia infection was 11% (12/107). To assess the effectiveness of Giardia vaccination for treatment of Giardia carriage, 9 additional asymptomatic Giardia antigen-positive dogs were brought into the facility. The Giardia antigen-positive dogs were then randomly allocated to receive either vaccine (n = 10) or a saline placebo (n = 10). Feces were then monitored monthly for 6 mo for Giardia antigen and Giardia cysts. At weeks 4, 8, 12, and 16 following vaccination, there were more Giardia-positive dogs in the vaccinated group (10/10, 9/10, 9/10, 8/10, respectively) compared with the controls (7/10, 7/10, 8/10, 4/10, respectively). At week 20, an equal number of dogs (5/10) were Giardia positive, and at week 24, fewer dogs were positive in the vaccinated group than in the control group (2/10 versus 5/10, respectively). However, there was no significant difference between the 2 groups. Vaccination was, therefore, not an effective treatment for asymptomatic canine Giardia infections in this setting.
authors.affiliation: Animal Care Services, University of Guelph, Guelph, Ontario N1G 2W1.
authors.forename: Kirsten A
authors.initials: KA
authors.lastname: Anderson
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Brooks
authors.forename: Annette L
authors.initials: AL
authors.lastname: Morrison
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Reid-Smith
authors.forename: S Wayne
authors.initials: SW
authors.lastname: Martin
authors.forename: Denna M
authors.initials: DM
authors.lastname: Benn
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Peregrine
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis*; D004283:Dog Diseases / Q000453:epidemiology / Q000517:prevention & control*; D004285:Dogs; D005243:Feces / Q000469:parasitology; D005260:Female; D005872:Giardia / Q000276:immunology*; D005873:Giardiasis / Q000453:epidemiology / Q000517:prevention & control / Q000662:veterinary*; D008297:Male; D009864:Ontario; D015995:Prevalence; D016052:Protozoan Vaccines / Q000008:administration & dosage*; D011897:Random Allocation; D013997:Time Factors; D016896:Treatment Outcome; D014611:Vaccination / Q000592:standards / Q000662:veterinary
chemical_list: D000953:Antigens, Protozoan; D016052:Protozoan Vaccines