The association between submission counts to a veterinary diagnostic laboratory and the economic and disease challenges of the Ontario swine industry from 1998 to 2009.

An intuitive assumption is to believe that the number of submissions made to a veterinary diagnostic laboratory is dictated by the financial state of the industries using the laboratory. However, no research is available to document how the economics of a food animal industry affects laboratory submissions and therefore disease monitoring and surveillance efforts. The objective of this study was to determine if economic indices associated with the Ontario swine industry can account for the variability seen in these submissions. Retrospective swine submissions made to the Animal Health Laboratory at the University of Guelph, Guelph, Ontario from January 1998 to July 2009 were compiled. The following economic, demographic, and health variables impacting Ontario swine production were selected for analysis: auction price, lean-hog futures, currency exchange rate, price of corn, an outbreak of porcine circovirus type-2 associated diseases (PCVAD), government incentive program, number of farms in province, and average farm size. All independent variables identified by unconditional associations to have a significance of P≤0.2 with the outcome of monthly submission count were included in a multivariable negative binomial model. A final model was identified by a backwards elimination procedure. A total of 30,432 swine submissions were recorded. The mean frequency of monthly submissions over 139 months was 212.9 (SD=56.0). After controlling for farm size, the number of pigs in Ontario, higher submission counts were associated with a weaker CAD$ versus US$, higher auction prices, and a PCVAD outbreak (P<0.001). The results suggest that both economic volatility and disease outbreaks in the Ontario swine industry drive submissions to the laboratory. In conclusion, lab submissions are a useful source of animal health data for disease surveillance; however, surveillance activities should also monitor the economics of the industry.