PSV-A-13 - Using Canine Olfaction to Detect Bovine Respiratory Disease: An Analysis of Two Dogs’ Performance

Abstract: Bovine respiratory disease (BRD) detection is a major challenge in feedlot cattle management. In a pilot study, two dogs were trained using sets of three samples to identify nasal swabs from cattle that developed signs of BRD after feedlot arrival. Cattle arrived at the feedlot in four lots and included a mixture of bulls (n=306) and steers (n=89). In the final stage of training, Dog A accuracy was 0.82 (95% CI: 0.79-0.85) and Dog B accuracy was 0.63 (95% CI: 0.60-0.67). A Kruskal-Wallis test identified differences in accuracy across lots (P < 0.001). Differences between pairs were identified by Wilcoxon tests. Accuracy for Lot 2 (0.53, 95% CI: 0.46-0.59) was lower than all other lots. The greatest accuracy, 0.96 (95% CI: 0.92-1.00), was for sets where the positive sample came from a different lot than both negative samples, and differed from accuracy for all lots except Lot 4. A Wilcoxon test detected no differences (p = 0.76) in accuracy between sets that consisted of all bulls (0.73, 95% CI: 0.69-0.76) and sets that were a mixture of bulls and steers (0.72, 95% CI: 0.69-0.75). After training, in a double-blind detection test, unfamiliar samples (n=123) were presented to the dogs as 41 sets. Each set was evaluated twice by each dog. Accuracy for Dog A was 0.39 (95% CI: 0.28-0.50), no better than chance; however, Dog B’s accuracy was 0.45 (95% CI: 0.34-0.56), better than the 0.33 expected by chance. In the detection test, neither sample lot (p = 0.33) nor sex (p = 0.11) impacted performance for either dog. Dogs’ consensus accuracy was 0.54 (95% CI: 0.38-0.69). Overall, dogs showed some ability to discriminate between BRD-affected and healthy cattle using nasal swabs, however multiple compounding factors may have influenced canines’ decision making in this trial.