The use of an intermittent schedule of reinforcement to evaluate detection dogs' generalization from smokeless-powder.

Odor generalization is essential for detection dogs. Regardless of its importance, limited research is available on detection dog odor generalization. The objectives of this study were (1) evaluate the use of an intermittent schedule of reinforcement to assess generalization in dogs and (2) evaluate olfactory generalization from a single exemplar of smokeless powder (SP). Dogs (N = 5) were trained to detect SP in an automated olfactometer under an intermittent schedule of reinforcement where only 60% of correct responses were reinforced. After training, eight non-reinforced probe trials were inserted within a session. A total of 15 testing odors were evaluated across 15 consecutive sessions (one odor/session). Six of the testing odors were control and the remaining testing odors were objects indirectly exposed to SP, objects that contained or were directly exposed to SP, single-base SP and diphenylamine (the main volatile present in the headspace of SP). Dogs' response rate to all testing odors except for the cotton gauzes and t-shirt cloths exposed to the headspace of SP, the simulated IED, and Getxent tubes exposed to direct contact with SP were statistically lower than their response rate of actual SP. The response rate to SP was not different across all 15 testing sessions suggesting that the intermittent schedule of reinforcement, maintained dog motivation and performance. Data show that the outlined method is a good approach to study generalization in detection dogs. These results also highlight dog generalization to SP varieties and associated odors.

Training with varying odor concentrations: implications for odor detection thresholds in canines.

Detection dogs are required to detect trace quantities of substances, many times in the parts per billion or parts per trillion concentration range. Frequently, detection of trace quantities is not explicitly trained but rather assumed when dogs show proficiency at higher concentrations to which they are trained. The aim of this study was to evaluate the effect of the odor concentration of the training sample on the minimum concentration dogs will subsequently detect. We expected that dogs may not spontaneously generalize to trace odor concentration when trained with higher concentrations, but when trained to a range of lower concentrations, dogs will show superior detection to lower untrained concentrations. A total of 11 dogs were randomly assigned to 2 groups and were trained to alert to isoamyl acetate at 0.01% odor dilution (v/v with mineral oil) using a 3-alternative forced choice test. Once reaching proficiency, odor detection threshold was assessed using a 2-down 1-up descending staircase procedure. Next, experimental dogs received training with systematically lower concentrations of isoamyl acetate and threshold re-assessed. Control dogs were yoked to experimental dogs in terms of training time, but only received training to the 0.01% dilution between threshold assessments. Experimental dogs showed significantly improved detection thresholds, outperforming control dogs by detecting an average dilution about 100-fold lower. Results suggest that explicitly training for lower concentrations is critical for generalization for trace odor detection.

The influence of breed and environmental factors on social and solitary play in dogs (Canis lupus familiaris).

The domestic dog is an ideal model species in which to study the genetic and environmental factors that influence play behavior. Dogs exist in a wide variety of breeds and frequently engage in multiple forms of play. In the present study, we investigated whether the levels of solitary and social play differed between dogs of three breed types with distinct predatory motor pattern sequences (herding dogs, retrievers, and livestock guarding dogs [LGDs]). Furthermore, we investigated how environmental factors (social and nonsocial contexts) influenced play in dogs of these breed types. Groups of breed-matched dyads with working experience and of equivalent age, sex, and neuter status ratios were exposed to four experimental test conditions and two control conditions in randomized orders. With respect to solitary play, environmental context did have a significant effect, with toys reliably producing the highest levels of solitary play across all breed types. Retrievers engaged in significantly higher levels of solitary play overall than LGDs, and there was a trend in comparison to herding dogs. In contrast, neither environmental context nor breed had a significant effect on social play levels; however, neuter status of the dyads did have a significant effect on social play, with mixed-status dyads engaging in significantly higher levels of social play than same-status dyads. Our findings provide experimental evidence for identifying proximate, environmental stimuli that reliably facilitate social and solitary play and discuss possible genetic (i.e., breed type) and lifetime influences on the form of play in domestic dogs.

Behavioral and Self-report Measures Influencing Children's Reported Attachment to Their Dog.

Despite the prevalence of dogs as family pets and increased scientific interest in canine behavior, few studies have investigated characteristics of the child or dog that influence the child-dog relationship. In the present study, we explored how behavioral and self-report measures influence a child's reported feelings of attachment to their dog, as assessed by the Lexington Attachment to Pets Scale (LAPS). We tested specifically whether children (N= 99; Age: M= 10.25 years, SD= 1.31 years) reported stronger attachment to dogs that were perceived as being more supportive (measured by a modified version of the Network of Relationships Inventory), to dogs that are more successful in following the child's pointing gesture in a standard two-object choice test, or to dogs that solicited more petting in a sociability assessment. In addition, we assessed whether children's attachment security to their parent, and whether being responsible for the care of their dog, influenced reported feelings of attachment to the dog. Overall, perceived support provided by the dog was highly predictive of all subscales of the LAPS. The dog's success in following the child's pointing gesture and lower rates of petting during the sociability assessment were associated with higher ratings on the general attachment subscale of the LAPS, but not of other subscales of the LAPS. Caring for the dog did not predict the child's reported attachment to dog, but did predict the dog's behavior on the point following task and petting during the sociability task. If the child cared for the dog, the dog was more likely to be successful on the pointing task and more likely to be petted. These results indicate a dyadic relationship in which the child's care for the dog is associated with the dog's behavior on the behavioral tasks, which in turn is related to the child's reported feelings of attachment. The direction of influence and nature of this dyad will be a fruitful area for future research.

Effect of odor preexposure on acquisition of an odor discrimination in dogs.

In two experiments, we investigated the impact of odor preexposure treatments on the acquisition of an olfactory discrimination in dogs. In the first experiment, four groups of dogs were each given five days' odor-exposure treatment prior to discrimination training. Dogs in the exposure group were exposed to anise extract (S+) for 30 min daily. Dogs in the Pavlovian-relevant pairing group received six daily delayed-conditioning trials to the same S+. The Pavlovian-irrelevant pairing group received conditioning trials to almond extract (S'). Dogs in the control group received no pretreatment. All of the dogs were then trained to detect S+ from a background pine odor (an AX-vs.-X discrimination). The Pavlovian-relevant pairing group acquired the odor discrimination significantly faster than all of the other exposure and control groups, and the remaining groups acquired the discrimination at the same rate as the no-exposure control group. In a second experiment, we extended these results to a within-subjects design using an AX-versus-BX discrimination. Six dogs were simultaneously trained on two different odor discriminations, one discrimination in which the S+ was previously Pavlovian conditioned, and one discrimination in which the S+ was novel. All of the dogs learned the odor discrimination with the previously conditioned S+ faster than they learned the novel odor discrimination, replicating the results of Experiment 1, and demonstrating that familiarity in the form of Pavlovian conditioning enhances odor-discrimination training. The potential mechanisms of the facilitated transfer of a Pavlovian conditioned stimulus to discrimination training are discussed.

Dogs' ability to detect an inflammatory immune response in cattle via olfaction.

Introduction: Canine olfaction is a potential means for detection of respiratory disease in beef cattle. In a prior study, two dogs were trained to discriminate between nasal swabs from healthy cattle and cattle that developed Bovine Respiratory Disease. Dogs had some ability to identify samples from BRD-affected cattle, but results were ambiguous. The purpose of this study was to evaluate more dogs using better-controlled training and testing procedures. Methods: Nasal and saliva swabs were collected from 96 cattle before and after administering a vaccine to induce an inflammatory immune response. Samples were stored at -80°C for up to 11 months before use, and samples from animals with an elevated body temperature at baseline were omitted. An automated olfactometer apparatus was constructed to improve blinding procedures and reduce opportunities for odor contamination. Four dogs were trained to distinguish between swabs from healthy and sickness-model cattle, including the two dogs from the previous study ("Runnels" and "Cheaps") and two inexperienced dogs ("Molokai" and "Amy"). During a seven-month training period, dogs were exposed to samples from 28 animals. Dogs were tested on 59 sets of unfamiliar samples. Results: Performance varied among dogs (χ2 = 10.48, p = 0.02). Molokai's performance was above chance (0.73 ± 0.06, p = 0.0006), while Amy (0.44 ± 0.06, p = 0.43), Cheaps (0.53 ± 0.07, p = 0.79), and Runnels (0.56 ± 0.06, p = 0.43) did not respond correctly at a rate different from chance. Accuracy did not differ between nasal swabs (0.63 ± 0.08) and saliva swabs (0.53 ± 0.08, χ2 = 0.81, p = 0.37). Discussion: The results of this study indicate that canine olfaction may be an effective means of detecting illness in beef cattle. However, individual dogs' aptitude for this detection task varies.

Canine detection of explosives under adverse environmental conditions with and without acclimation training.

Canines are one of the best biological detectors of energetic materials available; however, canine detection of explosives is impacted by a number of factors, including environmental conditions. The objectives of this study were: 1) determine how canine detection limits vary when both the canine and odorant are tested in varying temperature and humidity conditions (canine and odor interactive effects); and 2) determine if an acclimatization plan can improve detection limits in an adverse environmental condition. Eight working line canines were trained to detect four energetics: prill ammonium nitrate (AN), Composition 4 (C4), trinitrotoluene (TNT) and double base smokeless powder (SP). In Experiment 1, canines completed a 3-alternative forced choice 3-down-1-up staircase threshold assessment in five environmental conditions: 40°C and 70% relative humidity (RH), 40°C and 40% RH, 0°C and 90% RH, 0°C and 50% RH and 21°C and 50% RH. Canines showed a 3.5-fold detection limit increase (poorer detection) for C4 in 40°C and 70% RH compared to their detection limit at 21°C and 50% RH. In Experiment 2, the eight canines were split into two groups (n = 4), control and acclimation groups. The control group completed the threshold assessment for C4 at 21°C and 50% RH each day for 20 days, with 5 minutes of petting prior to testing. The acclimation group completed the same assessment daily starting at 21°C and 50% RH but temperature and RH were incremented daily over the course of 6 days to the 40°C and 70% RH condition. After the initial six days, the acclimation group completed daily assessments at 40°C and 70% RH condition for the remainder of the experiment. All acclimatization group canines started their session with 5 minutes of toy or food retrieves. Detection limits for C4 for all dogs were tested in 40°C and 70% RH on day 11 and day 22. The acclimatization plan improved detection limits in the 40°C and 70% RH condition for C4 compared to the non-acclimated group. In this set of experiments, canine detection limits for four explosive odorants were found to vary based on environmental condition and were mostly driven by impacts on the canine rather than odor availability. The acclimatization plan did result in lower detection limits (i.e., increased performance). Future work should determine what factor (exercise or environmental exposure) is more effective in acclimatization for odor detection work.

Evaluation of Volatile Organic Compounds from Spotted Lanternfly (Lycorma delicatula) Eggs Using Headspace Odor Sampling Methods.

The spotted lanternfly (SLF) is an invasive species native to China. It was first discovered in the United States in Pennsylvania in 2014. It is known to cause great economic damage by destroying various crops, specifically grape vines, and therefore, several efforts have been made to control and mitigate its spread from the Northeast. Canine detection is a useful detection tool; however, it is crucial to understand the volatile organic compounds emitting by this pest to better direct canine training paradigms to prevent false alerts and to understand potential volatile markers of importance indicative of this species. The purpose of this study is to address the gap in research regarding the volatile organic compound (VOC) profile of SLF to better inform pest control mitigation strategies. Instrumental analysis was performed utilizing SPME-GC/MS on cold-killed SLF eggs, dried crickets, and tree bark. Differences in detected VOCs within each sample set depicted distinctive odor profiles for each matrix tested. Storage of these samples also depicted VOC accumulation variation as a function of time, thereby providing implications for long-term storage and sample handling for these types of training aids in canine applications.

Environmental effects on explosive detection threshold of domestic dogs.

Detection canines are deployed to detect explosives in a wide range of environmental conditions. These environmental conditions may have negative impacts on canine capabilities as a sensor. This study leveraged an air dilution olfactometer to present controlled odor concentrations of four different energetic materials (double base smokeless powder, Composition C4, ammonium nitrate, and flake Trinitrotoluene) to dogs working in a range of high temperature, standard, and low temperature conditions with high and low humidity conditions. The air dilution olfactometer controlled concentrations independent of environmental condition. Dogs' detection threshold limits were measured using a descending staircase procedure. We measured dogs' threshold twice for each energetic under each environmental condition. Results indicated heterogeneity in effects based on energetic, but all odors were detected at their lowest concentrations under standard conditions. Smokeless powder detection was reduced under all environmental conditions compared to standard and was least detectable under high temperature and humidity conditions. AN detection was poorest under high temperature high and low humidity conditions. C4 in contrast, was least detectable at low temperatures with high humidity. TNT detection was difficult under all conditions, so decrements due to environmental conditions were not statistically detectable. Additional measures were also found to be associated with detection limits. Under high temperature conditions, correlations were observed between canine mean subcutaneous temperature and detection limits, such that dogs experiencing greater temperature increases showed poorer detection limits. In addition, dog's latency to sample the odor port from the onset of a trial was longest in the high temperature conditions. Longer latencies were also predictive of poorer detection performance. Overall, dogs showed deficits in detection sensitivity limits under all environmental conditions for at least one energetic material when the concentration of that energetic material was not directly impacted by the environmental conditions. These results suggest that behavioral factors related to environmental exposure can have important impacts on canine detection sensitivity and should be considered in operational environments.

Development of an automated human scent olfactometer and its use to evaluate detection dog perception of human scent.

Working Dogs have shown an extraordinary ability to utilize olfaction for victim recovery efforts. Although instrumental analysis has chemically characterized odor volatiles from various human biospecimens, it remains unclear what perceptually constitutes human scent (HS) for dogs. This may be in part due to the lack of methodology and equipment to train and evaluate HS perception. The aims of this research were 1) to develop an automated human scent olfactometer (AHSO) to present HS to dogs in a controlled setting and 2) use the AHSO to evaluate dogs' response to different scented articles and individual components of HS. A human volunteer was placed in a clear acrylic chamber and using a vacuum pump and computer-controlled valves, the headspace of this chamber was carried to one of three ports in a different room. Dogs were trained to search all three ports of the olfactometer and alert to the one containing HS. In Experiment 1 and 2, the AHSO was validated by testing two dogs naïve to HS (Experiment 1) and five certified Search and Rescue (SAR) teams naïve to the apparatus (Experiment 2). All dogs showed sensitivity and specificity to HS > 95% in the apparatus. In Experiment 3, we used a spontaneous generalization paradigm to evaluate generalization from the HS chamber to different scented articles exposed to the same volunteer and to a breath sample. Dogs' response rate to the different scented articles was < 10% but exceeded 40% for the breath sample. In Experiment 4, we replicated this result by re-testing spontaneous generalization to breath and when the volunteer had breath exhausted/removed from the chamber. Dogs' response rate to breath alone was 88% and only 50% when breath was removed. Altogether, the data indicate that exhaled breath is an important and salient component of HS under these conditions.

Calibrating canines-a universal detector calibrant for detection dogs.

Since the advent of the Universal Detector Calibrant (UDC) by scientists at Florida International University in 2013, this tool has gone largely unrecognized and under-utilized by canine scent detection practitioners. The UDC is a chemical that enables reliability testing of biological and instrumental detectors. Training a biological detector, such as a scent detection canine, to respond to a safe, non-target, and uncommon compound has significant advantages. For example, if used prior to a search, the UDC provides the handler with the ability to confirm the detection dog is ready to work without placing target odor on site (i.e., a positive control), thereby increasing handler confidence in their canine and providing documentation of credibility that can withstand legal scrutiny. This review describes the UDC, summarizes its role in canine detection science, and addresses applications for UDC within scent detection canine development, training, and testing.

A canine model to evaluate the effect of exercise intensity and duration on olfactory detection limits: the running nose.

Detection canines serve critical roles to support the military, homeland security and border protection. Some explosive detection tasks are physically demanding for dogs, and prior research suggests this can lead to a reduction in olfactory detection sensitivity. To further evaluate the effect of exercise intensity on olfactory sensitivity, we developed a novel olfactory paradigm that allowed us to measure olfactory detection thresholds while dogs exercised on a treadmill at two different exercise intensities. Dogs (n = 3) showed a decrement in olfactory detection for 1-bromooctane at 10-3 (v/v) dilutions and lower under greater exercise intensity. Dogs' hit rate for the lowest concentration dropped from 0.87 ± 0.04 when walking at low intensity to below 0.45 ± 0.06 when trotting at moderate intensity. This decline had an interaction with the duration of the session in moderate intensity exercise, whereby dogs performed near 100% detection in the first 10 min of the 8 km/h session, but showed 0% detection after 20 min. Hit rates for high odor concentrations (10-2) were relatively stable at both low (1 ± 0.00) and moderate (0.91 ± 0.04) exercise intensities. The paradigm and apparatus developed here may be useful to help further understand causes of operationally relevant olfactory detection threshold decline in dogs.

A mixed-methods analysis of similarities and differences in animal shelter staff, dog behavior professionals, and the public in determining kenneled dog welfare.

The ability of animal shelter employees to identify poor welfare states in kenneled dogs is crucial for the mitigation of suffering. Animal shelter employees (n = 28), animal behavior professional (n = 49), and the general public (n = 41) watched 10 videos of kenneled dogs then rated the welfare of the dogs, stated the rationale for their score, indicated how they would improve the welfare, and rated the feasibility of improvements. Professionals gave slightly lower (poorer) welfare scores compared to the public (z = -1.998, p = 0.046). Shelter employees (z = -5.976, p < 0.001) and professionals (z = 9.047, p < 0.001) used body language and behavior to explain their welfare scores more than the public. All three populations mentioned the addition of enrichment to improve the welfare, however, shelter employees (z = -5.748, p < 0.001) and professionals (z = 6.046, p < 0.001) mentioned it significantly more. There were no significant differences in the perceived feasibility of changes. Future research should explore possible reasons for the lack of welfare improvements within animal shelters.

Experimental analysis of canine behavior and cognition: Introduction to the special issue.

Over the last 3 decades, the use and popularity of canid models for basic and applied behavioral research has grown dramatically, and for good reasons. Dogs are uniquely among the human world, living and working in our homes and places of employment while an even greater population lives on the outskirts of human life, scavenging and navigating the city life. This provides a rich continuum of environmental contexts for the canine experience, leading to some unique and even human-like behaviors in animals. The articles in this special issue provide additional insight into factors that influence canine welfare, methods for evaluating dogs' preferences and the reinforcing effectiveness of stimuli, trick learning and retention, concept learning, and scent detection performance under sparse reinforcement conditions. Here we provide an overview of these articles and their contribution to our understanding of canine behavior.

Part, III: Increasing odor detection performance after training with progressively leaner schedules of odor prevalence.

Prior work has demonstrated canine search behavior and performance declines when challenged with infrequent target odors. The purpose of this study was to evaluate whether performance could be maintained in a low target odor prevalence context by explicitly training dogs through progressively leaner target odor schedules. In Experiment 1, nine control dogs were trained at 90% target prevalence rate. Nine experimental dogs were trained with progressively lower prevalence rates in 10% increments until reaching 20% prevalence with > 85% detection accuracy in the training context. Both groups were tested in the operational context at a 10% target odor prevalence. Experimental dogs had higher accuracy, hit percentage, and shorter search latency in the operational context compared with control dogs. In Experiment 2, twenty-three operational dogs were challenged with a target frequency of 10%, which resulted in 67% accuracy. Control dogs were then trained with 90% target frequency, whereas experimental dogs received a progressively decreasing target rate from 90% to 20%. The dogs were rechallenged with target frequencies of 10, 5, and 0%. Experimental dogs outperformed control dogs (93% vs. 82% accuracy) highlighting the effect of explicit training for infrequent targets.

A laboratory model of canine search vigilance decrement, I.

Previous studies have found that infrequent targets can reduce dogs' vigilance. The purpose of this study was to develop a laboratory model to evaluate the effects of infrequent targets on dogs' search behavior and performance. Dogs (n = 18) were trained to detect smokeless powder in an automated olfactometer in two distinct rooms ("operational" and "training"). During baseline, the dogs received five daily sessions at a high target odor frequency (90%) in both rooms. Subsequently, the frequency of the target odor was decreased to 10% only in the "operational" room but remained at 90% in the training room. Last, the odor prevalence was returned to 90% in both rooms. All dogs showed a significant decrement in detection performance in the operational room when the target odor frequency was decreased but simultaneusly mantained high performance in the training room. This decrement was largely due to decreases in adequate search behavior. All dogs recovered performance when the odor frequency was increased again to 90%. Trial accuracy was associated with tail position, search score, latency, and duration of environmentally directed behaviors. The data show that low target odor prevalence significantly reduced search behavior and performance and that there are behaviors that can be used by handlers to assess their dog's search state.

A laboratory model of canine search vigilance decrement, II: Noncontingent reward and Pavlovian appetitive stimuli.

Detection dogs have demonstrated reduced performance in operational settings when required to search in an environment where few to no target odors are present. This study's purpose was to increase detection dog accuracy using noncontingent reward (NCR) and Pavlovian stimuli associated with reward. Eighteen dogs were randomly spilt into two groups and received four 40-trial sessions in an operational and training context at 90% odor prevalence (baseline). Following baseline, in the operational context (now at 10% odor prevalence), experimental dogs received an NCR schedule consisting of delivering food rewards at the end of 66% of trials. After the NCR Test, dogs returned to baseline. During baseline, the experimental dogs received 10 days of delayed Pavlovian conditioning to a tone. During the test phase, the conditioned stimulus (tone) was presented to experimental dogs on average every two trials for 30 s in the operational context (now at 10% odor prevalence). Overall, NCR showed a nonsignificant trend for increased responding in the experimental group but tended to increase false alerts; therefore, a permutation of an NCR-like reward schedule may maintain search. The Pavlovian conditioned stimulus didn't decrease timeouts or improve accuracy, but a within-session analysis indicated that the dogs were more likely to time out and less likely to false alert when the tone was on than when it was off.

Explosive odor signature profiling: A review of recent advances in technical analysis and detection.

With the ever-increasing threat of improvised explosive devices (IEDs) and homemade explosives (HME) both domestically and abroad, detection of explosives and explosive related materials is an area of urgent importance for preventing terrorist activities around the globe. Canines are a common biological detector used in explosive detection due to their enhanced olfactory abilities, high mobility, efficient standoff sampling, and optimal identification of vapor sources. While other sensors based on different principles have emerged, an important concept for the rapid field detection of explosives is understanding key volatile organic compounds (VOCs) associated with these materials. Explosive detection technology needs to be on par with a large number of threats including an array of explosive materials as well as novel chemicals used in the manufacture of IEDs. Within this much needed area of research for law enforcement and homeland security applications, several studies have sought to understand the explosive odor profile from a range of materials. This review aims to provide a foundational overview of these studies to provide a summary of instrumental analysis to date on the various types of explosive odor profiles evaluated focusing on the experimental approaches and laboratory techniques utilized in the chemical characterization of explosive vapors and mixtures. By expanding upon these concepts, a greater understanding of the explosive vapor signature can be achieved, providing for enhanced chemical and biological sensing of explosive threats as well as expanding upon existing laboratory-based models for continued sensor development.

Consumer attitudes toward bacteriophage applications to pet food.

This study used a two-part questionnaire to investigate consumer knowledge and attitudes toward bacteriophage applications in pet food, pet food safety, and environmental sustainability. Part 1 included questions about pet food safety, sustainability, and knowledge and attitudes toward bacteriophages. Next, participants reviewed educational materials about each, and Part 2 assessed if this increased knowledge of, or changed attitudes toward, bacteriophage application. Participants (n = 80), were recruited through Amazon Mechanical Turk (MT) (n = 45) and Social Media (SM) (n = 35). Mean responses in Part 1 and Part 2 were compared by paired t-tests, and mean responses between MT and SM were compared by t-tests. Participants reported pet food safety was important to them (combined proportion strongly agree or agree, mean ± SD) (75/80, 94%, MT 4.66 ± 0.60, SM 4.71 ± 0.95) and were most concerned with raw pet food safety (51/80, 64%, MT 3.88 ± 0.80, SM 3.17 ± 1.40). Participants rated environmental sustainability as important (61/80, 76%, MT 3.86 ± 0.94, SM 3.97 ± 0.66); however, it was not a strong driver of pet food purchasing (26/80, 33%, MT 3.31 ± 1.25, SM 2.82 ± 0.82). Overall, data showed an increase in knowledge of bacteriophages following a review of educational material. However, in the SM group, no statistically significant difference was observed in the comfort eating food with bacteriophage additives (SM Part 1 3.37 ± 1.05, SM Part 2 3.48 ± 1.12, p = 0.279), whereas the MT group did show an increase (MT Part 1 3.57 ± 1.01, MT Part 2 4.08 ± 0.92, p < 0.001). In the SM group, no statistically significant difference was observed in comfort feeding their pet food with bacteriophage additives (SM Part 1 3.40 ± 1.03, SM Part 2 3.45 ± 1.14, p = 0.571), whereas the MT group did show an increase (MT Part 1 3.57 ± 0.98, MT Part 2 4.31 ± 0.84, p < 0.001). The strongest objections related to safety concerns (20/53, 38%, MT 2.83 ± 0.96, SM 3.27 ± 0.84). These results demonstrate that despite increasing knowledge, there is still hesitancy among some consumers toward bacteriophage applications in pet food.

Using Canine Olfaction to Detect Bovine Respiratory Disease: A Pilot Study.

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.