Use of a national veterinary hospital database for post-marketing surveillance of vaccine -associated adverse events in dogs

George Ed Moore, Purdue University

Abstract

This research was conducted to evaluate the usefulness of the Banfield, the Pet Hospital® medical record database for post-marketing surveillance of veterinary vaccines by describing the incidence of and risk factors for selected vaccine-associated adverse events (VAAE) in dogs. The database was searched for diagnoses of vaccine reaction, allergic reaction, urticaria, or anaphylaxis within 3 days of vaccination. In 2002 and 2003, the overall VAAE rate was 38.2 per 10,000 dogs vaccinated (4678 VAAE in 1,226,519 dogs). The VAAE rate decreased significantly as patient weight increased ( P for trend <0.001). The risk of VAAE significantly increased as the number of concurrent vaccinations increased (P < 0.001), and patient weight modified this effect. Risk was greater for neutered versus intact dogs, and VAAE risk was greatest for dogs approximately 1 to 3 years old (P < 0.001). These records were also used to detect potential space-time clustering of VAAE associated with rabies vaccination. Using a scan statistic for population rate data, significant (P = 0.001) clusters were identified involving the Atlanta and Tampa/St. Petersburg areas, from November 2002 through February 2003. Separate analyses of these cities using individual address coordinates identified one significant cluster (P = 0.002), associated with a 23.26 km-radius area in Atlanta (20 VAAE in 702 dogs; rate = 2.85%) from November 2002 through February 2003, warranting further investigations. The database was also evaluated to determine the incidence of diagnoses of canine immune-mediated hemolytic anemia (IMHA) or immune-mediated thrombocytopenia (IMT) occurring within 30 days post-vaccination (Vacc-Y) or during other 30-day periods not immediately following or including a vaccination (Vacc-N). The rates of IMHA diagnosis were 0.2205 and 0.1675 per 10,000 patient encounters in Vacc-Y and Vacc-N periods, respectively; rate ratio = 1.32 (P = 0.282); corresponding rates of IMT were 0.1136 and 0.0479; rate ratio = 2.37 ( P = 0.037). The odds of a diagnosis of IMHA within 30 days of vaccination significantly increased by 1% with each month of age (P < 0.0001). The odds of IMHA diagnosis during the 30 day post-vaccination period was significantly increased by 2-fold (P = 0.028), and for IMT by 3-fold (P = 0.043), for dogs weighing 11–20 kg compared to dogs weighing 10 kg or less.

Degree

Ph.D.

Advisors

Glickman, Purdue University.

Subject Area

Veterinary services

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