Introduction
Search-and-rescue (SAR) dogs are key to locating victims of disasters. To perform their duties, SAR dogs require robust health and targeted preventive care while being raised, during their rigorous training, and while on deployment. Previously published survey-based studies1–6 evaluated deployment morbidity for SAR dogs responding to earthquakes, terrorist attacks, and mudslides. In the 2010 Haiti earthquakes, the most commonly reported health event in SAR dogs was dehydration, while in the 2014 State Route 530 landslide the integumentary system was most affected.1,2 While the findings of those studies are useful, additional information about health events outside deployment is needed to help veterinarians and dog handlers provide appropriate preventive care and ensure that dogs have long and healthy working lives. Unfortunately, there have been no studies in SAR dogs that capture data outside active deployment.
Studies of police and military dogs, guide dogs, and working farm dogs reported that musculoskeletal and integumentary systems were among the most affected systems throughout their lives.7–11 Differences in the ways SAR dogs are raised, housed, and trained mean that these prior studies may not be directly applicable. There is a real need for studies to determine the most common types of health events that occur in SAR dogs’ lifetime and whether specific factors affect the risk of these conditions. To bridge this knowledge gap, we analyzed data collected from a longitudinal study of health and behavior in SAR dogs deployed following the terrorist attacks in the US on September 11, 2001, and a comparison group that were not.3–5 The aim of the analysis was to describe the incidence of nonsurgical health events in SAR dogs over their lifetime and determine whether deployment status, sex, and breed were risk factors.
Methods
Study design
The study was a 15-year longitudinal study that began in October 2001. The design is described in detail by Otto et al.4 Briefly, handlers for 150 SARS dogs were enrolled in a longitudinal study. Dogs were followed from enrollment until the end of the study, death, or when the handler withdrew from the study. Handlers were sent a survey each year to collect information about health events that occurred in the previous 12 months. Completion of the survey was voluntary. The study was approved by the IACUC of the University of Pennsylvania
At enrollment, the survey captured the dogs’ date of birth, sex, breed, reproductive status, training history, and prior medical conditions via written survey instruments previously described.4 Subsequent surveys collected information about health events in the previous 12 months, training and deployment history, and whether the dog had retired from SAR. The survey was converted to an electronic form prior to data collection in year 5 of the study and accessed via a password-protected website.
The health questions had a yes/no answer format for common events as well as open-ended formats for less common medical conditions their dog encountered in the previous year.
See previously published papers for further details about the dogs’ work and exposures during this deployment as well as previously published results detailing veterinary and behavioral findings.3–6,12
Classification of health data
Health events reported by the dog handler were defined as surgical or nonsurgical. Only nonsurgical events that occurred after September 11, 2001, were included in the analysis presented in this paper. The events were classified using an approach like that used by Otto et al.5 Specifically, health events were categorized by the affected body system and etiologic category. The body systems included cardiovascular, CNS, endocrine, gastrointestinal, urogenital, hematopoietic, integument, lymphoid, musculoskeletal, and respiratory.
The etiological categories were inflammatory, degenerative, traumatic injury, neoplastic, and proliferative. Inflammatory events encompassed infections, stiffness, and other events related to the response of inflammatory cells to the body. The degenerative category included events such as cognitive dysfunction and congenital megaesophagus that gradually worsen over time. Traumatic health events in dogs were those caused by sudden, unexpected events that result in physical injury or harm, such as car accidents, falls, bites, or other types of traumas. The neoplastic category included both confirmed events diagnosed by veterinarians and those reported by handlers or those presumed but without definitive diagnostics. Proliferative events included hyperadrenocorticism and pregnancy. Events that could not be classified were coded as a nonspecific category.
All health events were assigned to a single etiology and body system category. For events that could have been classified into more than 1 category, a uniform decision was made as to what group to use. Lyme disease, which could have been considered either hematopoietic due to the hematogenous spread or musculoskeletal due to the common clinical signs, was reported as an inflammatory hematopoietic condition each time. For aural hematomas, specific etiology was often unavailable, and the decision was made to classify the condition as an inflammatory integument condition. Anal gland infections were reported as inflammatory gastrointestinal disease rather than integument disease.
All designations were assigned by a veterinary student (ACS) and supervised and reviewed for consistency by a veterinarian who was board certified in veterinary emergency and critical care and veterinary sports medicine and rehabilitation (CMO).
Statistical analysis
For each etiological category and body system, the number and percentage of dogs that were reported with the event during the study, along with 95% CIs, were determined. The incidence rates for the first occurrence for events affecting the musculoskeletal, integumentary, and gastrointestinal systems were calculated. Events affecting other body systems were aggregated into “other.”
Incidence rates were calculated by dividing the total number of health events with the total number of days at risk and reported as the number of health events/100 dog-years at risk. This can be interpreted as the number of events that are likely to be observed if 100 dogs are followed for 1 year.
Time-at-risk calculations were determined for each body system. The start time for the time at risk calculation for each animal was September 11, 2001. For animals that were not recorded as having a health event affecting the body system, the time at risk was the cumulative sum of days until their death or the date the last survey was submitted if a date of death was not reported. For dogs that had a health event, the time at risk was the cumulative sum of days from the start of the study until the date of onset of their first event. When a specific date was not reported, the date of onset was entered as the date the survey was submitted. If no survey submission date was recorded, January 1 of the relevant year was used in place of the submission date. For example, in the survey period from July 2005 to June 2006, January 1, 2006, was used.
Incidence rates and 95% CIs for health events categorized as involving the musculoskeletal, integument, gastrointestinal, and other systems were calculated, stratified by deployment status (deployed on 9/11 / not deployed), sex (male/female), neuter status (neutered/entire), and breed (German Shepherd Dog / Labrador or Golden Retriever / Other). Incidence rate ratios, with Wald 95% CI, were calculated to describe the effect of deployment, sex, neuter status, and breed on health events. χ2 P values were used to determine whether there were statistically significant differences. Statistical significance was set at P < .05.
All data analysis was conducted with R, version 4.2.x, with Wald CIs and P values calculated using the Epitools package in R.13,14
Results
During the study period, 668 surveys were completed for the 150 dogs enrolled in the study (95 dogs that had been deployed to the 9/11 attack sites and 55 that had not been). Based on reported dates of death, the total number of possible survey responses was 1,144, resulting in an overall response rate of 58% throughout the course of the study.
At enrollment, the median age was 5 years (IQR, 3 to 7 years) and the median retirement age 10 years (n = 72; IQR, 8 to 11 years). At the completion of the study period, 149 of the dogs had been reported to be dead, and 1 was lost to follow-up, presumed deceased. The median age of death was 13 years (n = 149; IQR, 11 to 14 years). The study population was composed of 84 males and 65 females, and 119 (79%) of the dogs had been neutered. One dog did not have a recorded sex or neuter status. Fifty-four dogs were German Shepherd Dogs, 40 were Labrador Retrievers, and 14 were Golden Retrievers. The remaining 41 dogs included the following breeds: mixed breed (n = 9), Border Collie (8), and Australian Shepherd (5); Airedale Terrier, Australian Cattle Dog, Belgian Malinois, Belgian Tervuren, and Rottweiler (2 each); and Beauceron, Bloodhound, Doberman Pinscher, English Springer Spaniel, Giant Schnauzer, Hovawart, Louisiana Catahoula Leopard Dog, Newfoundland, and Pointer (1 each). One dog did not have a reported breed.
Whether dogs were full-time (typically associated with a law enforcement agency or fire department) SAR dogs was recorded at the beginning of the study period but is likely to have changed during the course of the dogs’ lives. Twenty-four of 150 dogs (16%) were reported to be full-time SAR dogs. Nineteen of 95 deployed dogs (20%) and 5 of 55 not-deployed dogs (9%) were reported to work full-time. Fifty-five of 150 dogs (34%) had been on at least 1 deployment prior to 9/11. Forty-six of 95 deployed dogs (48%) and 9 of 55 not-deployed dogs (16%) were reported to have been deployed prior to 9/11. Deployment and training data for both groups of dogs were summarized (Supplementary Table S1).
Over the study period, 95 of the 150 dogs (63%; 95% CI, 56% to 71%) had at least 1 nonsurgical health event during the study period. The most affected body systems were the musculoskeletal, integumentary, and gastrointestinal systems. The most common types of events were inflammatory and degenerative in nature (Table 1). Most conditions affecting the musculoskeletal system were inflammatory, degenerative, or traumatic in nature (Table 2). Similarly, inflammatory diseases were the most common to affect the integument and gastrointestinal systems. The incidence rates for different conditions stratified by body system and etiology are shown (Table 3).
Number and percentage of the 95 dogs that had a health event, stratified by type or body system affected. Note that percentages add up to more than 100%, as dogs could have health events in more than 1 body system during the study period.
| Health event | No. of dogs | Percentage |
|---|---|---|
| Type of event | ||
| Inflammatory | 65 | 68 |
| Degenerative | 41 | 43 |
| Traumatic injury | 41 | 43 |
| Neoplasia | 25 | 26 |
| Nonspecific | 7 | 7 |
| Proliferative | 3 | 3 |
| Body system affected | ||
| Musculoskeletal | 46 | 48 |
| Integument | 33 | 35 |
| Gastrointestinal | 28 | 29 |
| Nonspecific | 20 | 21 |
| Neurological | 19 | 20 |
| Urinary | 20 | 21 |
| Hematopoietic | 18 | 19 |
| Respiratory | 9 | 9 |
| Cardiovascular | 8 | 8 |
| Endocrine | 8 | 8 |
| Lymphatic | 5 | 5 |
| Renal | 3 | 3 |
Number and percentage of the 95 dogs that had a health event, stratified by body system affected, type of health event, and description. Note that dogs could have health events in more than 1 body system during the study period.
| Type of health event | Description | No. of dogs | Percentage |
|---|---|---|---|
| Musculoskeletal | |||
| Inflammatory | Pain and/or swelling | 15 | 16 |
| Infection | 1 | 1 | |
| Degenerative | Degenerative joint disease | 25 | 26 |
| Nonspecific | 4 | 4 | |
| Spondylosis | 2 | 2 | |
| Developmental defect | 1 | 1 | |
| Overuse injury | 1 | 1 | |
| Traumatic injury | Soft tissue injury | 24 | 25 |
| Fracture | 7 | 7 | |
| Dislocation/luxation | 3 | 3 | |
| Paralysis | 1 | 1 | |
| Not reported | 4 | 4 | |
| Other | Cancer | 4 | 4 |
| Overly flexible carpal joint | 1 | 1 | |
| Integument | |||
| Inflammatory | Infection (not ear) | 11 | 12 |
| Hot spot | 5 | 5 | |
| Ear infection | 4 | 4 | |
| Abscess | 1 | 1 | |
| Vaccine reaction | 1 | 1 | |
| Fistula | 1 | 1 | |
| Lupus | 1 | 1 | |
| Traumatic injury | Wounds and abrasions | 7 | 7 |
| Neoplasia | Tumor | 7 | 7 |
| Cyst | 4 | 4 | |
| Undiagnosed lump | 3 | 3 | |
| Skin tag | 1 | 1 | |
| Gastrointestinal | |||
| Inflammatory | Inflammatory disease | 12 | 13 |
| Infection | 9 | 9 | |
| Anal gland | 7 | 7 | |
| Vomiting and/or diarrhea | 6 | 6 | |
| Dentition | 2 | 2 | |
| Hepatitis | 2 | 2 | |
| Protein-losing enteropathy | 1 | 1 | |
| Gastric dilatation | 1 | 1 | |
| Ingested foreign substance | 1 | 1 | |
| Traumatic | Obstruction and/or foreign body ingestion | 3 | 3 |
| Broken teeth | 2 | 2 | |
| Vomiting and/or diarrhea | 1 | 1 | |
| Other | Gastroesophageal reflux | 1 | 1 |
| Congenital megaesophagus | 1 | 1 |
Number of dogs with a health event, total time at risk, and incidence rate (IR) in 150 search-and-rescue dogs that were reported to have at least 1 nonsurgical health event, stratified by body system affected and type of health event.
| Type of health event | No. of dogs | Total years at risk | IR/100 dog-years (95% CI) |
|---|---|---|---|
| Musculoskeletal | |||
| Inflammatory | 16 | 630 | 2.5 (1.6–4.1) |
| Degenerative | 24 | 612 | 3.9 (2.6–5.8) |
| Trauma | 22 | 586 | 3.8 (2.5–5.7) |
| Other type | 4 | 673 | 0.6 (0.2–1.6) |
| All musculoskeletal | 46 | 524 | 8.8 (6.6–11.7) |
| Integument | |||
| Inflammatory | 18 | 630 | 2.9 (1.8–4.5) |
| Degenerative | 0 | 677 | 0 |
| Trauma | 7 | 656 | 1.1 (0.5–2.2) |
| Other type | 13 | 653 | 2 (1.2–3.4) |
| All integument | 33 | 597 | 5.5 (3.9–7.8) |
| Gastrointestinal | |||
| Inflammatory | 24 | 594 | 4 (2.7–6) |
| Degenerative | 0 | 677 | 0 |
| Trauma | 6 | 656 | 0.9 (0.4–2) |
| Other type | 1 | 674 | 0.1 (0–1.1) |
| All gastrointestinal | 28 | 577 | 4.9 (3.4–7) |
| Other body systems | |||
| Inflammatory | 40 | 553 | 7.2 (5.3–9.9) |
| Degenerative | 28 | 622 | 4.5 (3.1–6.5) |
| Trauma | 12 | 647 | 1.9 (1.1–3.3) |
| Other type | 17 | 627 | 2.7 (1.7–4.4) |
| All other systems | 62 | 485 | 12.8 (10–16.4) |
| All body systems | |||
| Inflammatory | 65 | 457 | 14.2 (11.1–18.1) |
| Degenerative | 41 | 570 | 7.2 (5.3–9.8) |
| Trauma | 41 | 541 | 7.6 (5.6–10.3) |
| Other type | 33 | 598 | 5.5 (3.9–7.8) |
| All health events | 95 | 355 | 26.7 (21.9–32.7) |
In the dogs that were deployed, the incidence rate for any health condition was 28.7 incidents/100 dog-years, and in those that were not deployed the incidence rate was 23.7 incidents/100 dog-years; however, these differences were not statistically significant (P = .37; Table 4). Similarly, the incidence rate for health conditions affecting musculoskeletal, integumentary, and gastrointestinal systems did not differ significantly by deployment status. The incidence rate for health events in male and female dogs did not vary overall or for musculoskeletal, integumentary, and gastrointestinal systems (Table 5). However, when incidence rates were compared for other body systems, the incidence rate for dogs that were not deployed was 0.5 times as low as that for deployed dogs (95%CI, 0.3 to 0.9; P = .02) and was 1.6 times as high in female as in male dogs (95%CI, 1.0 to 2.7; P = .05). The neuter status and breed of the dog had no significant effect on the overall incidence rate of health events or the incidence rate for specific types of conditions (P > .05; Table 6).
Number of dogs with at least 1 reported health event and IR and IR ratio to the first health event, stratified by body system affected and deployment status to the 9/11 terrorist attacks. Data are from 95 dogs that were deployed and 55 dogs that were not. Significant P values are highlighted in bold.
| Body system | Deployed 9/11 | No. of dogs | Total years at risk | IR/100 dog-years (95% CI) | IR ratio (95% CI) | P (X2) |
|---|---|---|---|---|---|---|
| Musculoskeletal | Yes | 26 | 328 | 7.9 (5.4–11.7) | Reference | |
| No | 20 | 197 | 10.2 (6.6–15.8) | 1.3 (0.7–2.3) | .40 | |
| Integument | Yes | 20 | 363 | 5.5 (3.6–8.5) | Reference | |
| No | 13 | 233 | 5.6 (3.2–9.6) | 1.0 (0.5–2.0) | .97 | |
| Gastrointestinal | Yes | 18 | 356 | 5.1 (3.2 – 8.0) | Reference | |
| No | 10 | 221 | 4.5 (2.4–8.4) | 0.9 (0.4–1.9) | .78 | |
| Other | Yes | 45 | 281 | 16 (11.9–21.4) | Reference | |
| No | 17 | 204 | 8.3 (5.2–13.4) | 0.5 (0.3–0.9) | .02 | |
| All | Yes | 62 | 216 | 28.7 (22.4–36.8) | Reference | |
| No | 33 | 139 | 23.7 (16.8–33.3) | 0.8 (0.5–1.3) | .37 |
Number of dogs with at least 1 reported health event and IR and IR ratio to the first health event, stratified by body system affected, sex, and neutered status. Data are from 84 male and 65 female dogs and 119 neutered and 30 entire dogs. Note that 1 dog was excluded from analysis, as its sex and neuter status were not recorded. Significant P values are highlighted in bold.
| Body system | Variable | No. of dogs | Total years at risk | IR/100 dog-years (95% CI) | IR ratio (95% CI) | P (X2) |
|---|---|---|---|---|---|---|
| Sex | ||||||
| Musculoskeletal | Male | 28 | 258 | 10.8 (7.5–15.7) | Reference | |
| Female | 17 | 263 | 6.5 (4.0–10.4) | 0.6 (0.3–1.1) | .09 | |
| Integument | Male | 14 | 312 | 4.5 (2.7–7.6) | Reference | |
| Female | 19 | 281 | 6.8 (4.3–10.6) | 1.5 (0.8–3) | .24 | |
| Gastrointestinal | Male | 18 | 278 | 6.5 (4.1–10.3) | Reference | |
| Female | 10 | 294 | 3.4 (1.8–6.3) | 0.5 (0.2–1.1) | .10 | |
| Other | Male | 27 | 268 | 10.1 (6.9–14.7) | Reference | |
| Female | 35 | 212 | 16.5 (11.8–23) | 1.6 (1.0–2.7) | .05 | |
| All body systems | Male | 49 | 184 | 26.6 (20.1–35.2) | Reference | |
| Female | 45 | 169 | 26.7 (19.9–35.7) | 1.0 (0.7–1.5) | .99 | |
| Neuter status | ||||||
| Musculoskeletal | Yes | 36 | 422 | 8.5 (6.2–11.8) | Reference | |
| No | 9 | 100 | 9 (4.7–17.3) | 1.1 (0.5–2.2) | .88 | |
| Integument | Yes | 27 | 469 | 5.8 (3.9–8.4) | Reference | |
| No | 6 | 123 | 4.9 (2.2–10.9) | 0.8 (0.4–2.1) | .72 | |
| Gastrointestinal | Yes | 23 | 465 | 5 (3.3–7.5) | Reference | |
| No | 5 | 108 | 4.6 (1.9–11.1) | 0.9 (0.4–2.5) | .89 | |
| Other | Yes | 53 | 373 | 14.2 (10.8–18.6) | Reference | |
| No | 9 | 107 | 8.4 (4.4–16.1) | 0.6 (0.3–1.2) | .14 | |
| All body systems | Yes | 79 | 272 | 29.1 (23.3–36.3) | Reference | |
| No | 15 | 81 | 18.5 (11.2–30.7) | 0.6 (0.4–1.1) | .11 | |
Number of dogs with at least 1 reported health event and IR and IR ratio to the first health event, stratified by body system affected and breed. Data are from 54 German Shepherd Dogs (GSD), 54 Golden or Labrador Retrievers, and 41 dogs of other breeds. Note that 1 dog was excluded from analysis, as its breed was not recorded. Significant P values are highlighted in bold.
| Body system | Breed | No. of dogs | Total years at risk | IR/100 dog-years 95% CI) | IR ratio (95% CI) | P (X2) |
|---|---|---|---|---|---|---|
| Musculoskeletal | GSD | 17 | 181 | 9.4 (5.8–15.1) | Reference | |
| Retriever | 11 | 198 | 5.6 (3.1–10) | 0.6 (0.3–1.3) | .17 | |
| Other | 18 | 142 | 12.7 (8.0–20.2) | 1.4 (0.7–2.6) | .37 | |
| Integument | GSD | 10 | 213 | 4.7 (2.5–8.7) | Reference | |
| Retriever | 12 | 221 | 5.4 (3.1–9.6) | 1.2 (0.5–2.7) | .73 | |
| Other | 11 | 159 | 6.9 (3.8–12.5) | 1.5 (0.6–3.5) | .38 | |
| Gastrointestinal | GSD | 10 | 214 | 4.7 (2.5–8.7) | Reference | |
| Retriever | 9 | 197 | 4.6 (2.4–8.8) | 1.0 (0.4–2.4) | .96 | |
| Other | 8 | 165 | 4.9 (2.4–9.7) | 1.0 (0.4–2.6) | .93 | |
| Other | GSD | 21 | 169 | 12.4 (8.1–19) | Reference | |
| Retriever | 17 | 187 | 9.1 (5.7–14.7) | 0.7 (0.4–1.4) | .34 | |
| Other | 24 | 126 | 19.1 (12.8–28.4) | 1.5 (0.9–2.8) | .15 | |
| All body systems | GSD | 33 | 125 | 26.4 (18.7–37.1) | Reference | |
| Retriever | 29 | 142 | 20.4 (14.2–29.4) | 0.8 (0.5–1.3) | .32 | |
| Other | 32 | 88 | 36.3 (25.7–51.4) | 1.4 (0.8–2.2) | .19 |
Discussion
The study focused on exploring the impact of a single large-scale disaster response on the lifetime health of participating SAR dogs and providing information about incidence of health events over a lifetime. In doing so, the study was able to provide real-world data about the health of SAR dogs, which is key to their management. The most common medical events of SAR dogs involved the musculoskeletal, integumentary, and gastrointestinal systems. Handler-reported conditions most commonly fell into the categories of inflammatory, degenerative, and traumatic etiologies. For these and other major categories of medical events considered, there were no significant differences in the incidence of nonsurgical health events between those dogs that were deployed to 9/11 and those that were not. Therefore, we did not adjust for deployment status when looking at the impact of sex and breed on health event incidence rates. Additionally, there was no significant difference between breed and sex on incidence of health events.
For the musculoskeletal system, the most common diseases, in order, were inflammatory, degenerative, and traumatic events, and together they account for nearly 95% of all musculoskeletal events. The results were consistent with work in adult military working dogs and working farm dogs. A study of causes of retirement in military working dogs found that musculoskeletal causes, specifically spinal cord disease and osteoarthritis, were the most common causes.15 For noncombat injuries and illnesses in military working dogs, the musculoskeletal system was affected in nearly 15% of dogs.16 A survey of New Zealand working dogs found lameness as a major cause of dogs being unable to work.8,9 Overall, across working dog populations, musculoskeletal injuries pose a major threat to these dogs.
As musculoskeletal injuries are common among working dogs, deeper investigation into causes and prevention of SAR dog injuries/trauma would be impactful. For example, the relationship between body condition score and food restriction on working dog longevity and retirement warrants further investigation. Kealey et al17 reported a reduction in osteoarthritis and increased longevity in Labrador Retrievers on a food-restricted diet. In addition, the effect of a targeted and measurable canine fitness program18 on musculoskeletal health in SAR dogs should be investigated. The overall acceptable fitness requirement of working dogs is higher than companion animals, and their lifestyle should reflect that. Veterinarians should partner with handlers of SAR dogs to prioritize the prevention of musculoskeletal health events and maximize lifelong pain-free movement in these dogs.
Most events affecting the integumentary system in SAR dogs were inflammatory or caused by trauma. This was consistent with noncombat military working dogs, where integumentary conditions, predominantly ear infections and dermatitis, were the most common medical complaint and affected 25% of dogs.16 For our data set, the third most commonly reported etiology for the integumentary system was neoplasia. While neoplasia as a category was a common cause of mortality, reported in 32% of this group of SAR dogs, integumentary neoplasia was rarely associated with mortality (only 2/150 dogs).5 Two possible explanations for this finding are, first, that handlers may have been more likely to notice and report skin tumors and, second, many skin masses are benign.
Given the importance of the integumentary system for SAR dog health and well-being, future investigations should focus on preventing inflammatory and traumatic events. This could be in the form of ensuring monthly preventatives are taken, appropriate diet, development of specific decontamination protocols, and potentially genetic selection. Regional differences may influence the distribution, prevention and treatment of skin diseases. Additionally, being prepared with medical supplies onsite during deployments and having handlers trained on decontamination protocols specific to the associated hazard may help to prevent chronic integumentary conditions in the SAR dogs. Efforts have already begun in this field, with described protocols for oil and aerosolized contaminants that SAR dogs encounter.19,20
The third most common body system affected was the gastrointestinal system. This finding is similar to noncombat military working dogs,16 where gastrointestinal disease, primarily vomiting and diarrhea, was reported in over 15% of dogs. Within the gastrointestinal system, the most common types of health events were of an inflammatory or traumatic nature. Possible explanations for the high incidence of gastrointestinal disease could be that it is breed related, as a large portion of the dogs in this study were German Shepherd Dogs, which have previously been shown to have a high incidence of irritable bowel disease.21
When interpreting the health data, it is important to note that some events may have been underreported, as surveys covered a 12-month period. The events most likely to be underreported were those of short duration with limited impact. For example, short bouts of diarrhea and vomiting may not have been recalled and as such not reported. Therefore, the incidence of these events should be considered an underestimate. In contrast, the incidence rates for more significant injuries are likely to be reasonable, as handlers are more likely to recall these events.
The study numbers were limited to those that elected to participate in the 9/11 response or comparison group. We found no evidence that deployment impacted incidence of disease. However, it is possible that the study did not have sufficient power to detect differences. In addition, the dogs that deployed to the terrorist attack sites were older and more experienced than the dogs that did not deploy.4 Typically, SAR teams spend more time training than conducting formal searches, as is evident by the frequency of monthly training for both groups. The less experienced dogs may have been more likely to attend formal training to achieve certification.4 Dogs that retired from search or failed to progress to certification and left SAR may have contributed to the variability. In addition, not all handlers reported data each year. A more precise reporting mechanism for occupational hazard exposure during training and deployments would be valuable in monitoring and assessing SAR dogs for medical risk. Data quality was further limited by missing data from incomplete surveys and the fact that some participants did not submit a survey for every year of their dog’s life. However, some loss to follow-up is expected in any long-term study, and our average response rate falls well within the range of retention rates described in a meta-analysis of human longitudinal studies.22
Results of the current study showed that most common medical events observed in SAR dogs involve the musculoskeletal, integumentary, and gastrointestinal systems, with inflammatory, degenerative, and traumatic conditions being the most frequently reported. Importantly, there were no significant differences in the incidence of nonsurgical health events between the dogs deployed to 9/11 and those that were not, indicating that deployment status did not impact overall health outcomes. The results suggested that lifetime health of SARs dogs is not impacted by exposure to a single event. Further, the finding that musculoskeletal and integumentary systems are the most affected aligned with studies in other working dogs. There is an urgent need for research investigating how to prevent these conditions. It is essential that the research be undertaken in working dogs rather than pets, which have very different risk factors. Future research investigating causes of musculoskeletal injuries and options to prevent or manage conditions could focus on the role of body condition and targeted fitness programs. It is important to note that some health events may have been underreported and that missing data and nonresponse rates affected data quality. Despite these limitations, this study contributes to our understanding of SAR dog health and emphasizes the need for collaboration between veterinarians and handlers to prioritize prevention and optimize the lifelong well-being of these remarkable working dogs.
Supplementary Materials
Supplementary materials are posted online at the journal website: avmajournals.avma.org
Acknowledgments
The authors acknowledge the veterinarians and search-and-rescue handlers that provided samples and information.
Disclosures
The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.
Funding
This work was funded by the American Kennel Club Canine Health Foundation grants 0163, 0390, 0568, 0887A, 0961, 1943A, 2235A, and 2322.
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