title: Adverse events after vaccine administration in cats: 2,560 cases (2002-2005).
abstract: OBJECTIVE
  To determine the incidence of vaccine-associated adverse events (VAAEs) diagnosed within 30 days of vaccination in cats and characterize risk factors for their occurrence.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  496,189 cats vaccinated at 329 hospitals.
  
  
  METHODS
  Electronic records were searched for VAAEs that occurred after vaccine administration classified by practitioners as nonspecific vaccine reaction, allergic reaction, urticaria, shock, or anaphylaxis. Clinical signs and treatments were reviewed. The association between potential risk factors and a VAAE occurrence was estimated via multivariate logistic regression.
  
  
  RESULTS
  2,560 VAAEs were associated with administration of 1,258,712 doses of vaccine to 496,189 cats (51.6 VAAEs/10,000 cats vaccinated). The risk of a VAAE significantly increased as the number of vaccines administered per office visit increased. Risk was greatest for cats approximately 1 year old; overall risk was greater for neutered versus sexually intact cats. Lethargy with or without fever was the most commonly diagnosed VAAE. No localized reactions recorded in the 30-day period were subsequently diagnosed as neoplasia when followed for 1 to 2 years.
  
  
  CONCLUSIONS
  Although overall VAAE rates were low, young adult neutered cats that received multiple vaccines per office visit were at the greatest risk of a VAAE within 30 days after vaccination. Veterinarians should incorporate these findings into risk communications and limit the number of vaccinations administered concurrently to cats.
authors.affiliation: Department of Comparative Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907-2027, USA.
authors.forename: George E
authors.initials: GE
authors.lastname: Moore
authors.forename: Andrea C
authors.initials: AC
authors.lastname: DeSantis-Kerr
authors.forename: Lynn F
authors.initials: LF
authors.lastname: Guptill
authors.forename: Nita W
authors.initials: NW
authors.lastname: Glickman
authors.forename: Hugh B
authors.initials: HB
authors.lastname: Lewis
authors.forename: Lawrence T
authors.initials: LT
authors.lastname: Glickman
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D000367:Age Factors; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002369:Castration / Q000009:adverse effects / Q000662:veterinary; D002371:Cat Diseases / Q000276:immunology / Q000517:prevention & control; D002415:Cats; D015331:Cohort Studies; D005260:Female; D015994:Incidence; D008297:Male; D015999:Multivariate Analysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014611:Vaccination / Q000009:adverse effects / Q000662:veterinary*