2021 AAHA Working, Assistance, and Therapy Dog Guidelines

ABSTRACT The guidelines are the first comprehensive consensus report on veterinary healthcare recommendations for working, assistance, and therapy dogs. This category of canine patients includes a broad assortment of animals, some with well-defined functions and others that provide a more generalized support role. The guidelines discuss recommendations for dogs trained for protection, odor/scent detection, service functions for people with diagnosed disabilities or physical limitations, emotional support, and therapeutic intervention. Although the term is often used to describe dogs providing animal-assisted activities, true therapy dogs provide goal-directed therapy, often under the supervision of a healthcare professional such as an occupational therapist or psychologist. Many working dogs undergo extensive training and have rigorous physical demands placed upon them. These factors make working, assistance, and therapy dogs inherently valuable and impose a need for a high level of primary veterinary care as described in the guidelines. Because working dogs have a particularly close relationship with their handlers, a trust relationship between the practice team and the working-dog client is imperative.

Highly sensitive scent-detection of COVID-19 patients in vivo by trained dogs

Timely and accurate diagnostics are essential to fight the COVID-19 pandemic, but no test satisfies both conditions. Dogs can scent-identify the unique odors of volatile organic compounds generated during infection by interrogating specimens or, ideally, the body of a patient. After training 6 dogs to detect SARS-CoV-2 by scent in human respiratory secretions (in vitro diagnosis), we retrained 5 of them to search and find the infection by scenting the patient directly (in vivo screening). Then, efficacy trials were designed to compare the diagnostic performance of the dogs against that of the rRT-PCR in 848 human subjects: 269 hospitalized patients (COVID-19 prevalence 30.1%), 259 hospital staff (prevalence 2.7%), and 320 government employees (prevalence 1.25%). The limit of detection in vitro was lower than 10−12 copies ssRNA/mL. During in vivo efficacy experiments, our 5 dogs detected 92 COVID-19 positive patients among the 848 study subjects. The alert (lying down) was immediate, with 95.2% accuracy and high sensitivity (95.9%; 95% C.I. 93.6–97.4), specificity (95.1%; 94.4–95.8), positive predictive value (69.7%; 65.9–73.2), and negative predictive value (99.5%; 99.2–99.7) in relation to rRT-PCR. Seventy-five days after finishing in vivo efficacy experiments, a real-life study (in vivo effectiveness) was executed among the riders of the Metro System of Medellin, deploying the human-canine teams without previous training or announcement. Three dogs were used to examine the scent of 550 volunteers who agreed to participate, both in test with canines and in rRT-PCR testing. Negative predictive value remained at 99.0% (95% C.I. 98.3–99.4), but positive predictive value dropped to 28.2% (95% C.I. 21.1–36.7). Canine scent-detection in vivo is a highly accurate screening test for COVID-19, and it detects more than 99% of infected individuals independent of key variables, such as disease prevalence, time post-exposure, or presence of symptoms. Additional training is required to teach the dogs to ignore odoriferous contamination under real-life conditions.

Canine olfactory detection and its relevance to medical detection

The extraordinary olfactory sense of canines combined with the possibility to learn by operant conditioning enables dogs for their use in medical detection in a wide range of applications. Research on the ability of medical detection dogs for the identification of individuals with infectious or non-infectious diseases has been promising, but compared to the well-established and–accepted use of sniffer dogs by the police, army and customs for substances such as money, explosives or drugs, the deployment of medical detection dogs is still in its infancy. There are several factors to be considered for standardisation prior to deployment of canine scent detection dogs. Individual odours in disease consist of different volatile organic molecules that differ in magnitude, volatility and concentration. Olfaction can be influenced by various parameters like genetics, environmental conditions, age, hydration, nutrition, microbiome, conditioning, training, management factors, diseases and pharmaceuticals. This review discusses current knowledge on the function and importance of canines’ olfaction and evaluates its limitations and the potential role of the dog as a biomedical detector for infectious and non-infectious diseases.

Remote Medical Scent Detection of Cancer and Infectious Diseases With Dogs and Rats: a Systematic Review

Background: Remote medical scent detection of cancer and infectious diseases with dogs and rats has been an increasing field of research these last 20 years. If validated, the possibility of implementing such a technique in the clinic raises many hopes. This systematic review was performed to determine the evidence and performance of such methods and assess their potential relevance in the clinic.Methods: Pubmed and Web of Science databases were independently searched based on PRISMA standards. We included studies aiming at detecting cancers and infectious diseases affecting humans with dogs or rats. We excluded studies using other animals, studies aiming to detect agricultural diseases, diseases affecting animals, and others such as diabetes and neurodegenerative diseases. Only original articles were included. Data about patients’ selection, samples, animal characteristics, animal training and testing configurations, and performances were recorded.Results: A total of 62 studies were included. Sensitivity and specificity varied a lot among studies: While some publications report low sensitivities of 17% and specificities around 29%, others achieve rates of 100% sensitivity and specificity. Only 6 studies were evaluated in a double-blind screening like situation. In general, the risk of performance bias was high in most evaluated studies, and the quality of the evidence found was low.Conclusions: Medical detection using animals’ sense of smell lacks evidence and performances so far to be applied in the clinic. What odours the animals detect is not well understood. Further research should be conducted, focusing on patient selection, samples (choice of materials, standardization), and testing conditions. Interpolations of such results to free running detection (direct contact with humans) should be taken with extreme caution.

Highly sensitive scent-detection of COVID-19 patients in vivo by trained dogs

Timely and accurate diagnostics are essential to fight the COVID-19 pandemic, but no test satisfies both conditions. Dogs can scent-identify the unique odors of the volatile organic compounds generated during infection by interrogating specimens or, ideally, the body of a patient. After training 6 dogs to detect SARS-CoV-2 in human respiratory secretions (in vitro scent-detection), we retrained 5 of them to diagnose the infection by scenting the patient directly (in vivo scent-detection). Then, efficacy trials were designed to compare the diagnostic performance of the dogs against that of the rRT-PCR in 848 human subjects: 269 hospitalized patients (COVID-19 prevalence 30.1%), 259 hospital staff (prevalence 2.7%), and 320 government employees (prevalence 1.25%). The limit of detection in vitro was lower than 10-12 copies ssRNA/mL. In vivo, all dogs detected 92 COVID-19 patients present among the 848 study subjects. Detection was immediate, and independent of prevalence, time post-exposure, or presence of symptoms, with 95.2% accuracy and high sensitivity (95.9%; 95% C.I. 93.6-97.4), specificity (95.1%; 94.4-95.8), positive predictive value (69.7%; 65.9-73.2), and negative predictive value (99.5%; 99.2-99.7). To determine real-life performance, we waited 75 days to carry out an effectiveness assay among the riders of the Metro System of Medellin, deploying the human-canine teams without previous training or announcement. Three dogs (one of each breed) scent-interrogated 550 citizens who volunteered for simultaneous canine and rRT-PCR testing. Negative predictive value remained at 99.0% (95% C.I. 98.3-99.4), but positive predictive value dropped to 28.2% (95% C.I. 21.1-36.7). Canine scent-detection in vivo is a highly accurate screening test for COVID-19, and it detects more than 99% of infected individuals independently of the key variables. However, real-life conditions increased substantially the number of false positives, indicating the necessity of training a threshold for the limit of detection to discriminate environmental odoriferous contamination from infection.

Training with Multiple Structurally Related Odorants Fails to Improve Generalization of Ammonium Nitrate Detection in Domesticated Dogs (Canis familiaris)

A critical aspect of canine scent detection involves the animal’s ability to respond to odors based on prior odor training. In the current study, dogs (n = 12) were initially trained on an olfactory simple discrimination task using vanillin as the target odorant. Based on their performance on this task, dogs were assigned to experimental groups. Dogs in group 1 and 2 (n = 5 dogs/group; 1 dog/group were removed due to low motivation or high error rates) were trained with either two or six forms of ammonium nitrate (AN), respectively. Dogs were then assessed with a mock explosive with AN and powdered aluminum. Dogs in both groups failed to respond to the novel AN-aluminum odor. Mean success rates were 56 ± 5 and 54 ± 4% for groups 1 and 2, respectively. Overall, and individual dog performance was not statistically higher than chance indicating that dogs did not generalize from AN to a similar AN-based odorant at reliable levels desired for explosive detection dogs. These results suggest the use of authentic explosive materials, without the added complication of including category-learning methods, likely remains a cost-effective and efficient way to train explosive scent detection dogs.

Toward the use of medical scent detection dogs for COVID-19 screening

Current testing for the presence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus), which causes the novel coronavirus 2019 (COVID-19) infection, is typically reliant upon collection of nasal swab samples from subjects. These tests (reverse transcription polymerase chain reaction [RT-PCR] and antigen) are intrusive, can take significant time to process, and can give deleterious false negative and false positive results. Alternative methods for COVID-19 testing and screening are being studied, including the use of trained scent detection dogs to detect volatile organic compounds (VOCs) associated with the COVID virus. In August 2020 and October 2020, the first author (T.D.) searched MEDLINE/PubMed, Cochrane Library, Google Scholar, and additional news articles using keyword phrases including “COVID scent dogs,” “COVID sniffer dogs,” and “COVID detection dog,” returning a total of 13 articles, nine of which were duplicates. Four remaining peer-reviewed studies dedicated to determining the feasibility and efficacy of detecting and screening individuals who may be infected by the COVID-19 virus with scent detection dogs were then examined. In this narrative review, the authors describe the methodologies and results of the remaining four studies, which demonstrated that the sensitivity, specificity, and overall success rates reported by the summarized scent detection studies are comparable to or better than the standard RT-PCR and antigen testing procedures, meaning that scent detection dogs can likely be effectively employed to nonintrusively screen and identify individuals infected with the COVID-19 virus in hospitals, senior care facilities, schools, universities, airports, and even large public gatherings for sporting events and concerts.

Survey for Morro Bay Kangaroo Rat: A Rare Mammal of Uncertain Status

The Morro Bay kangaroo rat Dipodomys heermanni morroensis is a small, nocturnal, burrowing rodent endemic to the vicinity of Morro Bay in San Luis Obispo County, California. It was listed as endangered pursuant to the U.S. Endangered Species Act in 1973. Despite many searches over three decades, the Morro Bay kangaroo rat has not been captured or sighted in the wild since 1986. While recognizing that the Morro Bay kangaroo rat may be extinct, Kofron and Villablanca (2016) also speculated it may be persisting at extremely low density in isolated colonies, and they recommended surveying with wildlife scent-detection dogs and baited camera traps. We searched with a wildlife scent-detection dog and baited camera traps in four historically-occupied areas and detected no Morro Bay kangaroo rats. Unfortunately our data combined with all other existing data do not allow us to conclude whether the Morro Bay kangaroo rat is extinct or extant. Essentially, the international standard has not been met to make a definitive determination of extinction. That is, a species should be considered extinct only when there is no reasonable doubt that the last individual has died (International Union for the Conservation of Nature 2012). We acknowledge that because of resource limitation we surveyed only a small sample of the numerous patches of habitat in the expansive landscape. Further, we now consider the Morro Bay sand spit (total area 4.35 km2, foredunes 3.75 km2), a peripheral area, as potentially part of the geographic range with suitable habitat, and it has never been searched. Therefore, considering all available information, we conclude that the Morro Bay kangaroo rat must be considered as possibly extant. We recommend that search efforts continue in several specific areas, including the Morro Bay sand spit. If the Morro Bay kangaroo still exists, it will be challenging and difficult to rediscover because of its likely low density and patchy distribution in the expansive landscape, combined with its small size, nocturnal nature, and secretive lifestyle.

PSVI-28 Palatability and Scent Detection of Oxidation Levels in Poultry Meal

Pet food made from fresh and rendered high quality meat products are considered safe and nutritious products. Currently the main assessment of meat freshness and fat products is based on peroxide values (PV), quantifying secondary oxidation products such as aldehydes, ketones, and alcohols. Research on how rancidity or peroxidation affects the health/safety of pets has not been adequately investigated. Exploring how Labrador retrievers interact with PV associated aromas, the goal was to observe any correlations in canine aromatic preference to differing poultry meal PV levels. A pilot study was conducted to gather preliminary data and screen 60 Labrador Retrievers (30 male/30 female) for those best suited for this novel aromatic palatability approach. 10 Labrador Retrievers (5 male/5 female) were hand selected from the original group of 60, according to their willingness to interact repeatedly with the aromatic boxes designed to prevent consumption while allowing interaction with varied PV poultry meal aromas. Many dogs lost interest quickly when they learned they could not get to the inside contents of the boxes, making the pilot study a crucial step in the preliminary selection process. First approach was recorded for both trials as well as time spent interacting. Time spent at each box was converted to ratios and both were statistically analyzed. Data falling outside 2 standard deviations from the mean were deemed outliers and excluded from analysis. Ratio analysis examined over both trials pointed to a higher peroxide value (PV) preference, when paired with sample 1, especially sample 5. PV levels 2, 4, and 5 showed significantly higher (p=< 0.05) interaction times and 6 neared significance (P = 0.08), compared to PV level 1. Further exploration could compare all PV levels to one another, determining if a specific threshold or range of preference exists within the 6 levels we examined in this study.