2021 AAHA Working, Assistance, and Therapy Dog Guidelines.

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.

Retrospective evaluation and review of approaches for nonspecific lameness in dogs presented to an emergency service (2013-2014): 134 cases.

OBJECTIVE: This retrospective study aimed to characterize and evaluate the emergency approach, diagnosis, management, treatment, and follow-up of nonspecific canine lameness cases. DESIGN: Retrospective case series from September 25, 2013 to September 25, 2014. SETTING: The study was conducted at an urban university teaching hospital. ANIMALS: A consecutive sample of dogs presenting to the emergency service with nonspecific lameness in the designated timeframe was used to identify 134 cases. Owners were contacted to participate in the follow-up survey; dogs that died prior to data collection were excluded from the survey. Medical records were reviewed for lameness localization, etiology of lameness, diagnostics obtained, medications prescribed, and owner recommendations. INTERVENTIONS: Based on review of the medical records, the lameness localization, presumptive source of lameness (joint, soft tissue, neurological, or bone), diagnostics obtained, medications prescribed, and owner recommendations were recorded. Survey data included duration of lameness, perceived response to treatment, and activity level. MEASUREMENTS AND MAIN RESULTS: Definitive diagnoses were not assigned in 88.8% of lameness cases. A presumptive diagnosis of soft tissue injury was assigned in 45.3% of cases. Single limb lameness was more prevalent than multiple limb lameness. Owners whose dogs were treated with medication were significantly more likely to report that the lameness resolved (P = 0.049). Dogs with injury localized to ≥1 of the joints were significantly less likely to have resolution of lameness (P = 0.037). Treatment recommendations were predominantly pain control and activity restriction. CONCLUSIONS: Nonspecific lameness represents approximately 4% of canine urban emergency cases. Highlighting the points of clinical care considerations in understanding the etiology of lameness in dogs represents an opportunity for improved patient care and growth in emergency referral and follow-up.

A 15-year longitudinal study of search-and-rescue dogs identifies the musculoskeletal, integumentary, and gastrointestinal systems as commonly affected.

OBJECTIVE: A longitudinal study followed search-and-rescue (SAR) dogs for 15 years to determine the incidence of health events and whether factors of deployment during 9/11, breed, or sex altered the risk of specific events. ANIMALS: 150 SAR dogs: 95 dogs deployed to the September 11 terrorist attack sites and 55 SAR dogs not deployed. METHODS: Each year, a survey was sent to the handler to collect health information until the dog died or the handler withdrew from the study. The reported health events were then categorized according to the body system affected and etiology. Incidence risk rates, with 95% CIs, were calculated for the most common types of health events. Incidence rate ratios were calculated stratified by deployment status, sex, and breed and significance assessed. RESULTS: 1 or more health event was recorded in 96 of the 150 enrolled dogs. The most affected systems were the musculoskeletal (31%; CI, 24 to 39), integumentary (22%; CI, 15 to 29), and gastrointestinal (20%; CI, 14 to 26). The health events were most commonly reported as inflammatory (45%; CI, 37 to 53) and degenerative (28%; CI, 21 to 35) in nature. There were no significant differences in incidence of health events based on deployment status to the September 11, 2001, terrorist attacks. Additionally, there was no significant effect of breed or sex on incidence of health events. CLINICAL RELEVANCE: To improve the health and longevity of SAR dogs, disease prevention and management programs should focus on reducing the health problems involving the musculoskeletal system as well as the integumentary and gastrointestinal systems.

Assessing Different Chronic Wasting Disease Training Aids for Use with Detection Dogs.

Chronic wasting disease (CWD) is a highly infectious, fatal prion disease that affects cervid species. One promising method for CWD surveillance is the use of detection dog-handler teams wherein dogs are trained on the volatile organic compound signature of CWD fecal matter. However, using fecal matter from CWD-positive deer poses a biohazard risk; CWD prions can bind to soil particles and remain infectious in contaminated areas for extended periods of time, and it is very difficult to decontaminate the affected areas. One solution is to use noninfectious training aids that can replicate the odor of fecal matter from CWD-positive and CWD-negative deer and are safe to use in the environment. Trained CWD detection dogs' sensitivity and specificity for different training aid materials (cotton, GetXent tubes, and polydimethylsiloxane, or PDMS) incubated with fecal matter from CWD-positive and CWD-negative deer at two different temperatures (21 °C and 37 °C) for three different lengths of time (6 h, 24 h, and 48 h) were evaluated. Cotton incubated at 21 °C for 24 h was identified as the best aid for CWD based on the dogs' performance and practical needs for training aid creation. Implications for CWD detection training and for training aid selection in general are discussed.

Dogs can detect an odor profile associated with Staphylococcus aureus biofilms in cultures and biological samples.

Introduction: The study investigated the utilization of odor detection dogs to identify the odor profile of Staphylococcus aureus (S. aureus) biofilms in pure in vitro samples and in in vivo biosamples from animals and humans with S. aureus periprosthetic joint infection (PJI). Biofilms form when bacterial communities aggregate on orthopedic implants leading to recalcitrant infections that are difficult to treat. Identifying PJI biofilm infections is challenging, and traditional microbiological cultures may yield negative results even in the presence of clinical signs. Methods: Dogs were trained on pure in vitro S. aureus biofilms and tested on lacrimal fluid samples from an in vivo animal model (rabbits) and human patients with confirmed S. aureus PJI. Results: The results demonstrated that dogs achieved a high degree of sensitivity and specificity in detecting the odor profile associated with S. aureus biofilms in rabbit samples. Preliminary results suggest that dogs can recognize S. aureus volatile organic compounds (VOCs) in human lacrimal fluid samples. Discussion: Training odor detection dogs on in vitro S. aureus, may provide an alternative to obtaining clinical samples for training and mitigates biosecurity hazards. The findings hold promise for culture-independent diagnostics, enabling early disease detection, and improved antimicrobial stewardship. In conclusion, this research demonstrates that dogs trained on in vitro S. aureus samples can identify the consistent VOC profile of PJI S. aureus biofilm infections. The study opens avenues for further investigations into a retained VOC profile of S. aureus biofilm infection. These advancements could revolutionize infectious disease diagnosis and treatment, leading to better patient outcomes and addressing the global challenge of antimicrobial resistance.

Rehabilitation to Return-to-Work for Working Dogs.

This article highlights the differences between working dog careers, unique protocols associated with health care of a working dog and provides a practical guide to creating and managing a return-to-work program. The rehabilitative approach to a working dog consists of four distinct sequential phases: activity restriction, rehabilitation, return-to-work, and maintenance. The timeline through each phase is dependent on the degree of injury, treatment intervention, prior health status of the dog, and compliance of the handler. Return-to-work for a working dog is considered a success if the dog can perform all career-related activities safely and proficiently.

Machine learning prediction and classification of behavioral selection in a canine olfactory detection program.

There is growing interest in canine behavioral research specifically for working dogs. Here we take advantage of a dataset of a Transportation Safety Administration olfactory detection cohort of 628 Labrador Retrievers to perform Machine Learning (ML) prediction and classification studies of behavioral traits and environmental effects. Data were available for four time points over a 12 month foster period after which dogs were accepted into a training program or eliminated. Three supervised ML algorithms had robust performance in correctly predicting which dogs would be accepted into the training program, but poor performance in distinguishing those that were eliminated (~ 25% of the cohort). The 12 month testing time point yielded the best ability to distinguish accepted and eliminated dogs (AUC = 0.68). Classification studies using Principal Components Analysis and Recursive Feature Elimination using Cross-Validation revealed the importance of olfaction and possession-related traits for an airport terminal search and retrieve test, and possession, confidence, and initiative traits for an environmental test. Our findings suggest which tests, environments, behavioral traits, and time course are most important for olfactory detection dog selection. We discuss how this approach can guide further research that encompasses cognitive and emotional, and social and environmental effects.

A Randomized Cross-Over Study Comparing Cooling Methods for Exercise-Induced Hyperthermia in Working Dogs in Training.

Working dogs are at a high risk of canine non-pyrogenic hyperthermia, a life-threatening condition that can occur due to physical exertion or environmental factors that inhibit dogs' ability to cool themselves. Two frequently recommended cooling methods to reduce body temperature are water immersion and the application of isopropyl alcohol to paw pads. This cross-over study compared the relative efficacy of these methods in 12 working-dogs-in-training with post-exertional heat stress. On each study day, dogs had a physical exam and performed a warm-up exercise followed by sequential recalls in which dogs ran approximately 25 m between two designated handlers for 10 min until they showed multiple signs of heat stress or their core temperature reached 105 °F (40.6 °C). Dogs' temperature and heart rate were collected after each recall. Dogs completed three study days, and each day, randomly received one of three interventions: passive cooling (no intervention), partial water immersion, or isopropyl alcohol. Post-intervention dogs rested for 20 min. Partial water immersion and isopropyl alcohol both cooled dogs more than no intervention, and water immersion cooled dogs more efficiently than isopropyl alcohol. Additionally, the application of isopropyl alcohol raised dogs' heart rates more than water immersion or no intervention, suggesting that the process of applying isopropyl alcohol is potentially stressful to dogs. Thus, partial water immersion is preferred to cool dogs post-exertion due to its more efficient cooling and better tolerance of use.

Pharmacokinetics and pharmacodynamics of intranasal and intramuscular administration of naloxone in working dogs administered fentanyl.

BACKGROUND: Working dogs exposed to narcotics might require reversal in the field. OBJECTIVE: To explore the pharmacokinetic and pharmacodynamic effects of naloxone administered intramuscularly (IM) or intranasally (IN) to reverse fentanyl sedation in working dogs. ANIMALS: Ten healthy, working dogs aged 1.7 ± 1 year and weighing 26 ± 3 kg. METHODS: In this randomized, controlled cross-over study dogs received either 4 mg of naloxone IN or IM 10 minutes after fentanyl (0.3 mg IV) administration. Sedation was assessed at baseline and 5 minutes after fentanyl administration, then at 5, 10, 15, 20, 25, 30, 60 and 120 minutes after reversal with naloxone. Blood samples for naloxone detection were obtained at 0, 5, 10, 30, 60 and 120 minutes. Pharmacokinetic parameters and sedation scores were compared between IM and IN naloxone groups. RESULTS: There was a significant increase in sedation score from baseline (0.25 [-4 to 1] IM; 0 [-2 to 1] IN) after fentanyl administration (11 [5-12] IM; 9.25 [4-11] IN), followed by a significant reduction at 5 (0.5 [-0.5 to 1.5] IM; 1.25 [-1.5 to 4.5] IN) through 120 minutes (-0.5 [-2 to 1] IM; 0 [-4.5 to 1] IN) after reversal with naloxone. Route of administration had no significant effect on sedation score. Maximum plasma concentration was significantly lower after IN administration (11.7 [2.8-18.8] ng/mL IN, 36.7 [22.1-56.4] ng/mL IM, P < .001) but time to reach maximum plasma concentration was not significantly different from IM administration. CONCLUSION AND CLINICAL IMPORTANCE: Although IM administration resulted in higher naloxone plasma concentrations compared to IN, reversal of sedation was achieved via both routes after administration of therapeutic doses of fentanyl.

Canine detection of chronic wasting disease (CWD) in laboratory and field settings.

Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy that affects both free-ranging and farmed cervid species, including mule deer, white-tailed deer, and elk (Odocoileus hemionus, Odocoileus virginianus, and Cervus canadensis). Due to the long incubation period and variability of clinical signs, CWD can expand and spread to new areas before they reach diagnostically detectable levels. Antemortem testing methods currently available can be difficult to obtain and to be applied to the large numbers required for adequate surveillance. However, key volatile biomarkers could be harnessed for non-invasive antemortem surveillance. Detection dogs are the most effective tool currently available for volatile detection; dogs can effectively complete wildlife surveys at rates surpassing that of humans. This study is the first to demonstrate that trained detection dogs can be used as an antemortem test for CWD. First, we trained three dogs to differentiate between CWD-positive and CWD-negative white-tailed deer faeces in a laboratory setting. Dogs spent significantly more time at the positive sample than the negative samples, suggesting that they differentiated between the positive and negative volatile signatures. We then trained the same dogs to search for CWD-positive faecal samples in a more naturalistic field setting. In the field, dogs found 8/11 CWD-positive samples and had an average false detection rate of 13%. These results suggest that dogs can be trained to differentiate CWD-positive faeces from CWD-negative faeces in both laboratory and field settings. Future studies will compare canine accuracy to other antemortem methods, as well as improved canine training methods.

Canine Mobility Maintenance and Promotion of a Healthy Lifestyle.

This article highlights the recommendations and considerations for maintaining a healthy canine lifestyle. A key component of a healthy lifestyle is the enhancement and optimization of mobility. Mobility is essential in maintaining a high quality of life and involves the interplay of a dog's structure, posture, body condition score, physical exercise, and a healthy human-animal bond throughout a dog's lifetime.

Retention and future involvement in the American Kennel Club Junior Showmanship Program, a youth dog breed conformation competition.

Similar to other organizations that encourage positive youth development, the American Kennel Club (AKC) created the Junior Showmanship program to develop skills and pave a path for the next generation of competitors in canine conformation. Although participants age out of the Junior Showmanship Program when they turn eighteen, the hope is that Juniors will continue to be active in dog sports into adulthood. Females are overly represented in all age groups in this survey and in current participation. Although both males and females most commonly stopped participating at age 17 or 18, males had a significantly higher drop out at age 15. Further study is warranted to investigate factors specifically pertaining to male participation. A strong Belief System Model which accounted for positive responses associated with camaraderie and mentoring during the showmanship program was significantly (p=0.01) associated with commitment, member interest and active participation as an adult. In addition, success in the show ring was associated with future involvement in conformation or dog sports. Thus, both perceived achievement and mentorship by adult "volunteers" were associated with continued participation.

A Formalized Method to Acclimate Dogs to Voluntary Treadmill Locomotion at Various Speeds and Inclines.

The land treadmill is a multipurpose tool with a unique set of behavioral and physical benefits for training and assessing active dogs. Habituation to voluntary treadmill locomotion is crucial for training a dog or accurately assessing a dog's fitness on a treadmill. Therefore, a treadmill acclimation program was developed and evaluated with working dogs in training or working dogs performing detection research. Seven of eight naive dogs became acclimated to the treadmill using the protocol developed. Two previously experienced dogs successfully conducted an acclimation assessment to test for habituation to the treadmill. A muscle soreness protocol was created to evaluate the soreness developed during the acclimation program. This detailed protocol was successful in acclimating dogs to the treadmill at various safe speeds and inclines.

Effects of Intranasal and Oral Bordetella bronchiseptica Vaccination on the Behavioral and Olfactory Capabilities of Detection Dogs.

The bacterium Bordetella bronchiseptica is responsible for serious respiratory disease in dogs, most often associated with 'kennel cough' (canine infectious tracheobronchitis). It is recommended that dogs are vaccinated against the bacterium every 6-12 months, either by oral or intranasal administration. Any impairment of dogs' olfactory capabilities due to medical treatments may impact their efficiency and accuracy in their jobs. This study examined (1) the effect of intranasal and oral vaccines on the olfactory capabilities of detection dogs; as well as (1) effects of the vaccines on canine behavior. Dogs that were vaccinated initially with the oral and 28 days later with intranasal B. bronchiseptica were generally slower to find the target odor than the dogs that were assigned intranasal then oral vaccine. This result prompted a second between-subjects study to further investigate any impact of intranasal administration of the B. bronchiseptica vaccine on the olfactory capabilities of dogs. The intranasal vaccine was of particular interest due to its prevalent use and potential for nasal inflammation leading to decreased olfactory capabilities. Neither odor threshold nor time spent searching for odor were affected by the intranasal vaccine. Behavioral analyses showed that behaviors associated with the dogs' positive and negative motivation affected their time spent finding the target odor; this suggests that behavior should be considered in future studies of olfactory performance.

Dose Escalation Trial of Desulfated Heparin (ODSH) in Septic Peritonitis.

Objective: Septic peritonitis is associated with significant morbidity and mortality. As a potential therapeutic agent in the treatment of sepsis, 2-O, 3-O desulfated heparin (ODSH) reduces histones and platelet factor 4 (PF4) in mouse sepsis models. This pilot clinical trial evaluated the safety and effect of ODSH in client-owned dogs with septic peritonitis. Interventions: In an IACUC-approved, open-label, prospective, dose-escalation clinical trial in 6 dogs with spontaneous septic peritonitis, ODSH administration was initiated following surgical explore to achieve source control. Acute patient physiology and laboratory evaluation (APPLEfast and APPLEfull) scores on admission, source of septic peritonitis, requirement for vasopressors, the administration of blood products, and survival to discharge were recorded. Platelet count, cell free DNA (cfDNA) concentration, and platelet factor 4 (PF4) concentrations were measured at the time of each ODSH dosage. A dose of ODSH was administered every 8 hs for a total of 4 doses (maximum total dosage 75 mg/kg) based on a pre-determined escalation protocol. Patients were monitored in the ICU following administration for evidence of clinical hemorrhage. Main Results: The mean APPLEfast and APPLEfull scores on admission were 22 +/- 6 and 32 +/-10, respectively. Four dogs received 4 total dosages of ODSH and 2 dogs received 3 total dosages of ODSH intravenously. The mean total dosage of ODSH administered during the study period was 48.3 +/- 21.6 mg/kg. No dog required dose de-escalation or had any evidence of bleeding. Four dogs survived to discharge. Conclusions: No adverse effects of ODSH administration were documented in dogs with septic peritonitis. A randomized controlled trial is necessary to evaluate ODSH as a novel therapeutic in the treatment of septic peritonitis.

The first responder exposure to contaminating powder on dog fur during intranasal and intramuscular naloxone administration.

OBJECTIVE: To determine whether first responders delivering naloxone by either the IM or intranasal (IN) route were at risk of contamination with inert powder simulating canine opioid exposure. DESIGN: Prospective, crossover design. SETTING: Research study (university setting). ANIMALS: Ten clinically normal working dogs ranging from 9 to 44 months were enrolled based on training to detect odor and ability to be restrained with minimal stress. All enrolled dogs completed both arms of the study without adverse effects. INTERVENTIONS: Dogs were randomly assigned to fentanyl reversal with either IM or IN naloxone and then the alternate treatment after a 7-day washout period. Prior to reversal, dogs' heads were brushed with an inert glow-in-the-dark powder. First responders (the same 2 individuals for all dogs) performing the reversal were photographed under ultraviolet light prior to and 5 min after administering the medication. Digital photographs were scored by body region for presence of glowing powder by observers blinded to timing of photograph (pre- or postreversal) and route of reversal (IM vs IN). MEASUREMENTS AND MAIN RESULTS: Compared to pretreatment, the inert powder scores were higher after treatment regardless of route of naloxone administration (P < 0.001). IN administration led to higher contamination than IM naloxone, particularly in the chest area (P = 0.012). CONCLUSIONS: Both IN and IM naloxone administration to dogs with clinical signs of opioid exposure result in a risk of first responders becoming contaminated with powder, which could include opioids. Awareness, proper personal protective equipment, and appropriate posttreatment decontamination are important to reduce risk of inadvertent exposure of mucous membranes to these contaminating powders.

Genome scanning of behavioral selection in a canine olfactory detection breeding cohort.

Research on working dogs is growing rapidly due to increasing global demand. Here we report genome scanning of the risk of puppies being eliminated for behavioral reasons prior to entering the training phase of the US Transportation Security Administration's (TSA) canine olfactory detection breeding and training program through 2013. Elimination of dogs for behavioral rather than medical reasons was based on evaluations at three, six, nine and twelve months after birth. Throughout that period, the fostered dogs underwent standardized behavioral tests at TSA facilities, and, for a subset of tests, dogs were tested in four different environments. Using methods developed for family studies, we performed a case-control genome wide association study (GWAS) of elimination due to behavioral observation and testing results in a cohort of 528 Labrador Retrievers (2002-2013). We accounted for relatedness by including the pedigree as a covariate and maximized power by including individuals with phenotype, but not genotype, data (approximately half of this cohort). We determined genome wide significance based on Bonferroni adjustment of two quasi-likelihood score tests optimized for either small or nearly-fully penetrant effect sizes. Six loci were significant and five suggestive, with approximately equal numbers of loci for the two tests and frequencies of loci with single versus multiple mapped markers. Several loci implicate a single gene, including CHD2, NRG3 and PDE1A which have strong relevance to behavior in humans and other species. We briefly discuss how expanded studies of canine breeding programs could advance understanding of learning and performance in the mammalian life course. Although human interactions and other environmental conditions will remain critical, our findings suggest genomic breeding selection could help improve working dog populations.

The Use of Biological Sensors and Instrumental Analysis to Discriminate COVID-19 Odor Signatures.

The spread of SARS-CoV-2, which causes the disease COVID-19, is difficult to control as some positive individuals, capable of transmitting the disease, can be asymptomatic. Thus, it remains critical to generate noninvasive, inexpensive COVID-19 screening systems. Two such methods include detection canines and analytical instrumentation, both of which detect volatile organic compounds associated with SARS-CoV-2. In this study, the performance of trained detection dogs is compared to a noninvasive headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) approach to identifying COVID-19 positive individuals. Five dogs were trained to detect the odor signature associated with COVID-19. They varied in performance, with the two highest-performing dogs averaging 88% sensitivity and 95% specificity over five double-blind tests. The three lowest-performing dogs averaged 46% sensitivity and 87% specificity. The optimized linear discriminant analysis (LDA) model, developed using HS-SPME-GC-MS, displayed a 100% true positive rate and a 100% true negative rate using leave-one-out cross-validation. However, the non-optimized LDA model displayed difficulty in categorizing animal hair-contaminated samples, while animal hair did not impact the dogs' performance. In conclusion, the HS-SPME-GC-MS approach for noninvasive COVID-19 detection more accurately discriminated between COVID-19 positive and COVID-19 negative samples; however, dogs performed better than the computational model when non-ideal samples were presented.

Point seroprevalence of canine influenza virus H3N8 in dogs participating in a flyball tournament in Pennsylvania.

OBJECTIVE: To determine the seroprevalence of antibody against canine influenza virus H3N8 in a group of pet dogs that participate in flyball in Pennsylvania. DESIGN-SEROLOGIC SURVEY: Animals-Dogs attending a flyball tournament in Downingtown, Pa, from November 13 to 14, 2009. Procedures-Blood samples were collected from dogs following owner consent. Medical, travel, and activity history of the dogs for the previous 10.5 months was obtained from owners. Serum was harvested and submitted to Cornell University Diagnostic Laboratory for measurement of antibody against canine influenza virus H3N8 via hemagglutination inhibition testing. RESULTS: Serum samples were obtained from 100 of 256 dogs participating in the flyball event. Although 3 of the 100 (3%) samples had positive results for antibody against canine influenza, none of the associated dogs had respiratory signs of infection (eg, coughing, sneezing, or nasal or ocular discharge) in the 10.5 months prior to testing. Eleven dogs had a history of respiratory signs, but none of those dogs had antibody against canine influenza H3N8. In addition, none of the study dogs had been vaccinated against canine influenza H3N8. CONCLUSIONS AND CLINICAL RELEVANCE: Although canine influenza is considered enzootic in certain areas of the country (eg, Pennsylvania or New York), this study identified a low seroprevalence in dogs considered at high risk for infection given their life conditions and geographic origins. More research is warranted to elucidate the prevalence of exposure to the H3N8 virus in competitive sporting dogs and determine whether vaccination is warranted in such dogs.

Sports Medicine and Rehabilitation in Working Dogs.

Canine sports medicine and rehabilitation recently have evolved to embody the optimization of performance, injury prevention, and mitigation of musculoskeletal degeneration. This article discusses the diverse factors and considerations of working dog wellness and injury prevention and the importance of recognizing normal and abnormal posture and anatomic structure for performance evaluation and early indication of musculoskeletal injury. The importance of a canine physical fitness program is highlighted and the need for a 4-phase recovery plan to determine if a working dog can safely return to work after injury discussed.