Adverse events diagnosed within three days of vaccine administration in dogs

J Am Vet Med Assoc. 2005 Oct 1;227(7):1102-8. doi: 10.2460/javma.2005.227.1102.


Objective: To determine incidence rates and potential risk factors for vaccine-associated adverse events (VAAEs) diagnosed within 3 days of administration in dogs.

Design: Retrospective cohort study.

Animals: 1,226,159 dogs vaccinated at 360 veterinary hospitals.

Procedure: Electronic records from January 1, 2002, through December 31, 2003, were searched for possible VAAEs (nonspecific vaccine reaction, allergic reaction, urticaria, or anaphylaxis) diagnosed within 3 days of vaccine administration. Information included age, weight, sex, neuter status, and breed. Specific clinical signs and treatments were reviewed in a random sample of 400 affected dogs. The association between potential risk factors and a VAAE was estimated by use of multivariate logistic regression.

Results: 4,678 adverse events (38.2/10,000 dogs vaccinated) were associated with administration of 3,439,576 doses of vaccine to 1,226,159 dogs. The VAAE rate decreased significantly as body weight increased. Risk was 27% to 38% greater for neutered versus sexually intact dogs and 35% to 64% greater for dogs approximately 1 to 3 years old versus 2 to 9 months old. The risk of a VAAE significantly increased as the number of vaccine doses administered per office visit increased; each additional vaccine significantly increased risk of an adverse event by 27% in dogs < or = 10 kg (22 lb) and 12% in dogs > 10 kg.

Conclusions and clinical relevance: Young adult small-breed neutered dogs that received multiple vaccines per office visit were at greatest risk of a VAAE within 72 hours after vaccination. These factors should be considered in risk assessment and risk communication with clients regarding vaccination.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adverse Drug Reaction Reporting Systems
  • Age Factors
  • Animals
  • Body Weight / physiology*
  • Castration / adverse effects
  • Castration / veterinary
  • Cohort Studies
  • Dog Diseases / immunology
  • Dog Diseases / prevention & control
  • Dogs / immunology*
  • Female
  • Incidence
  • Male
  • Multivariate Analysis
  • Retrospective Studies
  • Risk Assessment*
  • Risk Factors
  • Vaccination / adverse effects
  • Vaccination / veterinary*