title: Efficacy of Giardia vaccination in the treatment of giardiasis in cats.
abstract: OBJECTIVE
  To assess efficacy of Giardia vaccination as a treatment for giardiasis in experimentally infected cats.
  
  
  METHODS
  Original study.
  
  
  METHODS
  16 young-adult cats.
  
  
  METHODS
  Cats were experimentally infected by orogastric administration of Giardia cysts. On weeks 4, 6, and 10, cats in the treatment group (n = 8) were given Giardia vaccine SC. For the first 28 weeks after infection, 3 fecal samples from each cat were examined weekly for Giardia cysts, and cyst numbers were counted. Fecal consistency was scored daily for the duration of the study. Results from vaccinated and unvaccinated cats were compared by logistic regression.
  
  
  RESULTS
  All cats became infected and were shedding Giardia cysts by the end of week 2. Throughout the study, diarrhea was rare and was mild and transient when it did occur. By week 28, 5 of 8 vaccinated cats and 7 of 8 control cats had patent Giardia infections. Magnitude of infection, based on number of fecal samples with cysts and number of cysts per sample, decreased progressively in both groups over time.
  
  
  CONCLUSIONS
  Administration of 3 doses of a Giardia vaccine did not completely eliminate the organism from experimentally infected cats in the study period. Since clinical signs were minimal in both groups of cats, it could not be determined whether vaccination lessened severity of clinical disease. Results may have been negatively influenced by the large inoculation dose. Whether Giardia vaccination is an effective treatment for giardiasis in naturally infected cats remains to be determined.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Stein
authors.forename: Steven V
authors.initials: SV
authors.lastname: Radecki
authors.forename: Michael R
authors.initials: MR
authors.lastname: Lappin
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000469:parasitology / Q000517:prevention & control*; D002415:Cats; D005243:Feces / Q000737:chemistry / Q000469:parasitology; D005260:Female; D005872:Giardia / Q000276:immunology*; D005873:Giardiasis / Q000517:prevention & control / Q000662:veterinary*; D007279:Injections, Subcutaneous / Q000662:veterinary; D016015:Logistic Models; D008297:Male; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000592:standards*; D011897:Random Allocation; D016896:Treatment Outcome; D014611:Vaccination / Q000592:standards / Q000662:veterinary*
chemical_list: D016052:Protozoan Vaccines