AN EVALUATION OF FACTORS AFFECTING HEARTWORM PREVALENCE AND DISTRIBUTION IN NORTHERN CALIFORNIA REVEALS THE NEED FOR MORE AGGRESSIVE EDUCATIONAL AND CONTROL PROGRAMS TO COMBAT THIS PARASITE

Data collected on 51, 194 dogs examined for filariasis in Northern Cal ifornia from January 1983 through December 1991 has revealed: manageme nt of dogs' indoor-outdoor status influences risk of infection; preval ence rates vary significantly between Plant Climate Zones; dogs are no t being examined for evidence of infection as early as they should be; prophylaxis is being started too late to prevent many infections in t he most populous age class; travel affects risk of infection; Plant Cl imate Zone temperatures and relative abundance of suitable vectors det ermine the transmission window size.