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.
Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in feedlot cattle and is a major welfare and economic concern. Identification of BRD-affected cattle using clinical illness scores is problematic, and speed and cost constraints limit the feasibility of many diagnostic approaches. Dogs can rapidly identify humans and animals affected by a variety of diseases based on scent. Canines' olfactory systems can distinguish between patterns of volatile organic compounds produced by diseased and healthy tissue. In this pilot study, two dogs (“Runnels” and “Cheaps”) were trained for 7 months to discriminate between nasal swabs from cattle that developed signs of BRD within 20 days of feedlot arrival and swabs from cattle that did not develop BRD signs within 3 months at the feedlot. Nasal swabs were collected during cattle processing upon arrival to the feedlot and were stored at −80°C. Dogs were presented with sets of one positive and two negative samples and were trained using positive reinforcement to hold their noses over the positive sample. The dogs performed moderately well in the final stage of training, with accuracy for Runnels of 0.817 and Cheaps of 0.647, both greater than the 0.333 expected by chance. During a double-blind detection test, dogs evaluated 123 unique and unfamiliar samples that were presented as 41 sets (3 samples per set), with both the dog handler and data recorder blinded to the positive sample location. Each dog was tested twice on each set of samples. Detection test accuracy was slightly better than chance for Cheaps at 0.451 (95% CI: 0.344–0.559) and was no better than chance for Runnels at 0.390 (95% CI: 0.285–0.496. Overall accuracy was 0.421 (95% CI: 0.345–0.496). When dogs' consensus response on each sample set was considered, accuracy was 0.537 (95% CI: 0.384–0.689). Detection accuracy also varied by sample lot. While dogs showed some ability to discriminate between BRD-affected and healthy cattle using nasal swabs, the complexity of this task suggests that more testing is needed before determining whether dogs could be effective as a screening method for BRD.
Capitalizing on canine olfactory capacity is a promising strategy for detecting and diagnosing human, animal, and plant diseases. The purpose of this review was to assess the extent of current research in canine disease detection. In this systematic review, multiple databases were searched for studies in which dogs were trained to detect diseases or health conditions. Following PRISMA guidelines, 1689 studies were screened and 50 relevant studies identified. The majority of studies (n = 31, 66%) took place in Europe. Lung cancer (n = 11, 22%), prostate cancer (n = 8, 16%), and breast cancer (n = 7, 14%) were the most frequently-studied conditions. Urine (n = 17, 34%) and breath (n = 9, 18%) were the most common sample types. Across all studies, 166 unique detection dogs were tested. The most numerous breed was Labrador Retrievers (n = 24, 14.46%). The median number of dogs per study was 2 (range: 1–20). To analyze experimental design and results, studies including multiple test paradigms were divided into sub-studies (n = 90). In 84.4% of sub-studies (n = 76), dogs were presented with sets of samples and 74.4% (n = 67) reported a constant number of samples per trial. The median number of samples per trial was 7 (range: 2–100). Of the sub-studies reporting a fixed number of positive samples (range: 1–10; n = 55), 87% (n = 48) presented one positive sample per trial. A plurality of sub-studies (n = 44, 49%) presented samples in a lineup. Sensitivity (median: 0.90; range: 0.13 to 1.0; n = 77) and specificity (median: 0.96; range: 0.08 to 1.0; n = 69) were the predominant measures of detection success, although reporting strategies were inconsistent. Dogs appear to have the capacity to detect disease via olfaction; yet the nascent nature of this discipline yields little consistency across studies.
Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in feedlot cattle and is therefore a major welfare and economic concern. Identification of BRD-affected cattle using clinical illness score is problematic, and speed and cost constraints limit the feasibility of many diagnostic approaches. Dogs can rapidly identify humans and animals affected by a variety of diseases based on scent. Canines’ olfactory systems can distinguish between patterns of volatile organic compounds produced by diseased and healthy tissue. In this pilot study, two dogs were trained for seven months to discriminate between nasal swabs from cattle that developed signs of BRD within twenty days of feedlot arrival and swabs from cattle that did not develop BRD signs within three months at the feedlot. Nasal swabs were collected during cattle processing upon arrival to the feedlot and were stored at -80°C. Dogs were presented with sets of one positive and two negative samples and were trained using positive reinforcement to hold their noses on the positive sample. The dogs performed moderately well in the final stage of training, with accuracy for Dog A of 0.817 and Dog B of 0.647. During a double-blind detection test, dogs evaluated 123 unique and unfamiliar samples that were presented as 41 sets (3 samples per set), with both the dog handler and data recorder blinded to the positive sample location. Each dog was tested twice on each set of samples. Detection test accuracy was slightly better than the 0.333 expected by chance for Dog B at 0.451 (95% CI: 0.341-0.565) and was no better than chance for Dog A at 0.390 (95% CI: 0.284-0.504. Overall accuracy was 0.421 (95% CI: 0.344-0.500). While dogs showed some ability to discriminate between BRD-affected and healthy cattle using nasal swabs, the complexity of this task suggests that more testing is needed before identifying whether dogs could be effective as a screening method for BRD.
The Hamilton-Zuk hypothesis indicates that parasites may have a negative effect on the appearance of sexual traits within an infected individual. Anolis sagrei, or brown anoles, are small invasive lizards common throughout Florida and many other areas where they have been introduced. The colorful dewlaps under the chins of males are used as a signal during territorial contests with other males and as an ornament to attract females. Anoles may be infected by the malaria parasite Plasmodium floridense. In this study, we investigated the relationship of malarial infection with dewlap color and spectral brightness of A. sagrei. We achieved this by capturing male brown anoles, taking blood samples to examine for malarial infection, and recording the color of their dewlaps. We found that the dewlaps of infected Anolis sagrei had duller coloration than the dewlaps of uninfected lizards. These results provide support for the Hamilton-Zuk hypothesis. Our results suggest that infection by P. floridense could potentially influence fitness of the lizards by reducing the expression of their color signals. Additional research on fitness effects of the malaria parasite on anoles is important for fully understanding this phenomenon.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.