Deep learning models for interpretation of point of care ultrasound in military working dogs.

Introduction: Military working dogs (MWDs) are essential for military operations in a wide range of missions. With this pivotal role, MWDs can become casualties requiring specialized veterinary care that may not always be available far forward on the battlefield. Some injuries such as pneumothorax, hemothorax, or abdominal hemorrhage can be diagnosed using point of care ultrasound (POCUS) such as the Global FAST® exam. This presents a unique opportunity for artificial intelligence (AI) to aid in the interpretation of ultrasound images. In this article, deep learning classification neural networks were developed for POCUS assessment in MWDs. Methods: Images were collected in five MWDs under general anesthesia or deep sedation for all scan points in the Global FAST® exam. For representative injuries, a cadaver model was used from which positive and negative injury images were captured. A total of 327 ultrasound clips were captured and split across scan points for training three different AI network architectures: MobileNetV2, DarkNet-19, and ShrapML. Gradient class activation mapping (GradCAM) overlays were generated for representative images to better explain AI predictions. Results: Performance of AI models reached over 82% accuracy for all scan points. The model with the highest performance was trained with the MobileNetV2 network for the cystocolic scan point achieving 99.8% accuracy. Across all trained networks the diaphragmatic hepatorenal scan point had the best overall performance. However, GradCAM overlays showed that the models with highest accuracy, like MobileNetV2, were not always identifying relevant features. Conversely, the GradCAM heatmaps for ShrapML show general agreement with regions most indicative of fluid accumulation. Discussion: Overall, the AI models developed can automate POCUS predictions in MWDs. Preliminarily, ShrapML had the strongest performance and prediction rate paired with accurately tracking fluid accumulation sites, making it the most suitable option for eventual real-time deployment with ultrasound systems. Further integration of this technology with imaging technologies will expand use of POCUS-based triage of MWDs.

Incidence of Intra-abdominal Adhesions Following Intraperitoneal Injection of Hemostatic Products in Rabbits.

INTRODUCTION: Definitive management of non-compressible intra-abdominal hemorrhage (NCIAH) currently requires a surgeon and operating room capable of performing damage control surgery. In a wartime scenario or a geographically remote environment, these may not be readily available. In this study, we sought to test the safety of 2 emerging injectable hemostatic agents (CounterFlow and Fast Onset Abdominal Management, or FOAM, poloxamer component) versus normal saline control over a prolonged monitoring duration following administration by a non-surgical provider. MATERIALS AND METHODS: The Institutional Animal Care and Use Committee approved all research conducted in this study. We randomized male New Zealand white rabbits into 2 monitoring cohorts of 24 hours and 2 weeks. Each cohort contained 3 treatment groups (n = 4 rabbits/group): CounterFlow, the testable poloxamer component of FOAM, and normal saline control. We injected each treatment intraperitoneally in the left lower abdominal quadrant. Doses were 15 mL/kg for CounterFlow, 6.3 mL/kg for the poloxamer component of FOAM, and 15 mL/kg for normal saline. We conducted all injections under isoflurane anesthesia monitored by trained veterinary staff. Animals were euthanized at each cohort end point, and a veterinary pathologist blinded to treatment type performed necropsy. The primary outcome was incidence of intra-abdominal adhesions at necropsy. Quantitatively, adhesions when present were graded by the veterinary pathologist on a 1 to 4 scale, where "1" represented adhesions involving from 1 to 25% of the examined abdomen, "2" represented from 26 to 50%, "3" represented from 51 to 75%, and "4" represented from 76 to 100%. Qualitatively, adhesions present were graded by degree ("1" = minimal, "2" = mild, "3" = moderate, and "4" = severe) and chronicity ("1" = acute, "2" = subacute, and "3" = chronic). We also drew d-dimer blood values and measured body weights for each animal. Statistical analysis included either repeated measures 2-way ANOVA or a mixed-effects model (in the case of missing data) with Geisser-Greenhouse correction. We adjusted multiple comparisons using Tukey statistical hypothesis tests. RESULTS: In the 2-week cohort, 3 CounterFlow animals showed adhesions judged to be "1" quantitatively. Qualitatively, 2 of these were assessed as "1" for degree of adhesions and the other demonstrated a "2." On the chronicity of adhesions scale, 1 animal demonstrated a "2" and 2 demonstrated a "3." No animals in other groups (FOAM and control) demonstrated adhesions. CounterFlow-treated animals showed a statistically significant rise in d-dimer values in the 24-hour cohort only. In the 2-week cohort, CounterFlow-treated animals showed a decrease in body weight at 24 hours after injection but returned to their baseline (normal) body weights at 7 days. CONCLUSIONS: Findings from this study demonstrate that the tested ingredients of FOAM poloxamer component are safe for intraperitoneal injection and hold potential for further study directed toward prehospital non-compressible intra-abdominal hemorrhage management by non-surgical providers. Although CounterFlow produced abdominal adhesions in 3 of 4 rabbits in the 2-week cohort, these were determined to be "minimal" or "mild" in degree.

Comparing the effects of various fluid resuscitative strategies on Glycocalyx damage in a canine hemorrhage model.

Hemorrhagic shock and subsequent resuscitation can cause significant dysregulation of critical systems, including the vascular endothelium. Following hemorrhage, the endothelial lining (glycocalyx) can shed, causing release of glycocalyx components, endothelial activation, and systemic inflammation. A canine model of hemorrhagic shock was used to evaluate five resuscitation fluids, including Lactated Ringers+Hetastarch, Whole Blood (WB), Fresh Frozen Plasma+packed Red Blood Cells (FFP+pRBC), and two hemoglobin-based oxygen carrier (HBOC) fluids, for their impact on glycocalyx shedding. Under anesthesia, purpose-bred adult canines were instrumented and subjected to a controlled hemorrhage with blood being drawn until a mean arterial pressure of <50 mmHg was reached or 40 % of the estimated blood volume was removed. Canines were left in shock for 45 mins before being resuscitated with one of the resuscitation fluids over 30 mins. Following resuscitation, the dogs were monitored up to 2 weeks. Following an additional 3-4 weeks for washout, the canines repeated the protocol, undergoing each resuscitation fluid individually. Blood samples were collected during each round at various timepoints for serum isolation, which was used for detection of glycocalyx biomarker. Comparison of baseline and post-hemorrhage alone showed a significant reduction in serum protein (p<0.0001), heparan sulfate (p<0.001), and syndecan-1 (p<0.0001) concentrations, and a significant increase in hyaluronan (p<0.0001) concentration. Intercomparisons of resuscitation fluids indicated minimal differences in glycocalyx markers over time. Comparisons within each fluid showed dynamic responses in glycocalyx biomarkers over time. Relative to individual baselines, syndecan-1 was significantly reduced after resuscitation in most cases (p<0.0001), excluding WB and FFP+pRBC. In all cases, VE-cadherin was significantly elevated at 24 hr compared to baseline (p<0.001). Hyaluronan was significantly elevated by 3 hr in all cases (p<0.01), except for HBOC fluids. Total glycosaminoglycans were significantly reduced only at 3 hr (p<0.001) for non-HBOC fluids. Similarly, heparan sulfate was significantly reduced with all fluids between resuscitation and 24 hr (p<0.01), except WB. The temporal changes in canine glycocalyx biomarkers were atypical of hemorrhage response in other species. This suggests that the hemorrhage lacked severity and/or typical glycocalyx biomarkers do not reflect the canine endothelium compared to other species. Further research is needed to characterize the canine endothelium and the response to resuscitation fluids.

Comparison of shelf-stable and conventional resuscitation products in a canine model of hemorrhagic shock.

BACKGROUND: Treatment of severe hemorrhagic shock typically involves hemostatic resuscitation with blood products. However, logistical constraints often hamper the wide distribution of commonly used blood products like whole blood. Shelf-stable blood products and blood substitutes are poised to be able to effectively resuscitate individuals in hemorrhagic shock when more conventional blood products are not readily available. METHODS: Purpose-bred adult dogs (n = 6) were anesthetized, instrumented, and subjected to hemorrhagic shock (mean arterial pressure <50 mm Hg or 40% blood volume loss). Then each dog was resuscitated with one of five resuscitation products: (1) lactated ringers solution and hetastarch (LRS/Heta), (2) canine chilled whole blood (CWB), (3) fresh frozen plasma (FFP) and packed red blood cells (pRBC), (4) canine freeze-dried plasma (FDP) and hemoglobin-based oxygen carrier (HBOC), or (5) HBOC/FDP and canine lyophilized platelets (LyoPLT). Each dog was allowed to recover after the hemorrhage resuscitation event and was then subjected to another hemorrhage event and resuscitated with a different product until each dog was resuscitated with each product. RESULTS: At the time when animals were determined to be out of shock as defined by a shock index <1, mean arterial pressure (mmHg) values (mean ± standard error) were higher for FFP/pRBC (n = 5, 83.7 ± 4.5) and FDP/HBOC+LyoPLT (n = 4, 87.8 ± 2.1) as compared with WB (n = 4, 66.0 ± 13.1). A transient increase in creatinine was seen in dogs resuscitated with HBOC and FDP. Albumin and base excess increased in dogs resuscitated with HBOC and FDP products compared with LRS/heta and CWB ( p < 0.01). CONCLUSION: Combinations of shelf-stable blood products compared favorably to canine CWB for resolution of shock. Further research is needed to ascertain the reliability and efficacy of these shelf-stable combinations of products in other models of hemorrhage that include a component of tissue damage as well as naturally occurring trauma.

Factors associated with medical problems among young non-deployed U.S. military working dogs.

The goals of this project were to quantify medical problems among a population of Military Working Dogs (MWDs) and analyze factors associated with common medical conditions. Medical conditions recorded in veterinary Master Problem List (MPL) entries for 774 young, non-deployed, active MWDs were categorized and combined with demographic information to analyze risk factors. Most dogs were male (74%), German Shepherd (39%) or Belgian Malinois (31%) breeds, certified in Explosive Detection (60%), and had a dark coat color (83%). Ages ranged from one to six years, with an average of 2.6 years (± 0.5 years). Eighty-three percent of dogs had a non-surgical medical problem in their record. The most common non-surgical medical problems were dermatologic (25% of MPL entries), alimentary (21%), dental (15%), soft-tissue injury (10%), and musculoskeletal conditions (4%). Factors associated with each medical condition were breed (Odds Ratios 1.96-8.24), sex and spay/neuter status (ORs 1.78-5.77), occupational duty certification (ORs 2.65-3.62), military command location (ORs 2.32-7.44), and military branch (OR 5.16). As MWDs are a valuable asset for the Department of Defense, training and work conditions for the identified at-risk groups of MWDs should be further assessed to maximize their operational capabilities and assess the potential to serve as sentinel indicators for human diseases. Improved understanding of the most common medical problems affecting MWDs, and the identification of factors associated with these conditions, can help drive changes in their preventive care.

Serum D-lactate concentrations in dogs with parvoviral enteritis.

BACKGROUND: Dogs infected with canine parvovirus (CPV) have compromised intestinal epithelial barrier integrity. Production of D-lactate by enteric bacteria may directly reflect disease severity or contribute to metabolic acid-base status in these dogs. HYPOTHESIS: Serum D-lactate concentration will be increased in CPV dogs compared to healthy controls and correlate with markers of disease severity and acid-base status. ANIMALS: Dogs with CPV undergoing treatment (n = 40) and healthy control dogs (n = 9). METHODS: Prospective observational study. Dogs with CPV had a baseline and daily CBC, venous blood gas with serum electrolyte concentrations, composite clinical severity score, and serum D-lactate concentration performed. A single serum D-lactate measurement was obtained from healthy control dogs. RESULTS: The CPV dogs had a higher D-lactate concentration (mean ± SD) of 469 ± 173 µM compared to controls, 306 ± 45 µM (P < .001). There was no difference in baseline D-lactate concentrations for CPV survivors (474 ± 28 µM), versus nonsurvivors (424 ± 116 µM; P = .70). D-lactate concentration decreased over the first 4 days of treatment (-9.6 µM/d; P = .46). Dogs hospitalized for <4 days had lower baseline D-lactate concentrations compared to those hospitalized ≥4 days (400 ± 178 µM versus 520 ± 152 µM; P = .03). No sustained correlation over time between serum D-lactate concentration and clinical severity score or recorded acid-base results. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum D-lactate concentrations are higher in dogs with CPV compared to healthy controls but do not appear to be clinically relevant. No relationship identified between serum D-lactate concentrations and markers of CPV disease severity, acid-base status, or outcome.

Treatment of Mal de Debarquement Syndrome in a Deployed Environment.

We report the case of a 26-year-old Caucasian female with persistent sensations of forward and reverse movement with spontaneous onset. This worsened over 4 wk. The patient reported an episode of these symptoms 5 mo prior, which lasted for 3 mo before improving. Our case details the treatment of Mal de Debarquement syndrome, or Disembarkment Syndrome, in a deployed military environment. Mal de Debarquement was a term originally coined to describe the persistent sensation of rocking back and forth after disembarking a boat and returning to land. This is normal, and usually only lasts for minutes to hours. When it persists, it is called Mal de Debarquement Syndrome. The onset frequently coincides with travel and most commonly by boat, however it can also occur spontaneously as in this case. Currently, there are three different treatment options. The first involves medications that are often sedating. The second uses magnetic resonance imaging at high frequency to stimulate the areas of the brain thought to be involved. The third option is a form of physical therapy termed re-adaptation of the vestibular ocular reflex. As we were in a deployed military environment the first two options were unsafe and unavailable respectively. We employed an improvised version of re-adaptation of the vestibular ocular reflex. The patient demonstrated a 50% reduction in symptoms following 1 wk of treatment and as a result was safely able to complete her deployment.

Evaluation of an outpatient protocol in the treatment of canine parvoviral enteritis.

OBJECTIVE: To compare 2 treatment protocols (standard in-hospital versus modified outpatient) in affecting the duration of treatment or survival of dogs with parvoviral enteritis. DESIGN: Prospective, randomized study. SETTING: University teaching hospital. ANIMALS: Client-owned dogs with naturally acquired parvovirus were randomized to receive either an inpatient (n = 20) or outpatient (n = 20) treatment protocol. INTERVENTIONS: Both groups received intravenous (IV) fluid resuscitation and correction of hypoglycemia at hospital admission. Following stabilization, basic inpatient interventions included administration of IV fluids, administration of cefoxitin (22 mg/kg IV q 8 h), and maropitant (1 mg/kg IV q 24 h). Basic outpatient interventions (provided in-hospital) included administration of subcutaneous (SC) fluid (30 mL/kg q 6 h), administration of maropitant (1 mg/kg SC q 24 h) and cefovecin (8 mg/kg SC once). Using daily electrolyte and glucose evaluations, dextrose and potassium supplementation was provided intravenously (inpatients) or orally (outpatients) as indicated. Rescue criteria were used in both groups for analgesia and nausea. All dogs were syringe fed a commercial canine convalescence diet (1 mL/kg PO q 6 h) until voluntary appetite returned. MEASUREMENTS AND MAIN RESULTS: Protocol success, defined as survival to hospital discharge, was 90% (18/20) for the inpatient group compared to 80% (16/20) for the outpatient group (P = 0.66). There was no difference detected in duration of hospitalization for inpatient dogs (4.6 ± 2 days) versus outpatient dogs (3.8 ± 1.8 days, P = 0.20). Metabolic disturbances were frequent in the outpatient group, with 50% of dogs requiring dextrose supplementation and 60% of dogs requiring potassium supplementation. CONCLUSIONS: An outpatient protocol may be a reasonable alternative for dogs that cannot receive standard in-hospital treatment for parvoviral enteritis. Diligent supportive care and monitoring are still required to optimize treatment of dogs with parvoviral enteritis in an outpatient setting.

Thromboelastographic evidence of inhibition of fibrinolysis after ε-aminocaproic acid administration in a dog with suspected acute traumatic coagulopathy.

OBJECTIVE: To describe the thromboelastographic changes in fibrinolysis with ε-aminocaproic acid treatment in a dog with suspected acute traumatic coagulopathy. CASE SUMMARY: A 9-year-old female spayed Airedale Terrier was presented with multiple injuries consistent with motor vehicle trauma. After surgical repair of a diaphragmatic hernia and minor laceration of the right cranial lung lobe, the dog continued to produce copious volumes of hemorrhagic fluid from the thoracic cavity despite multiple plasma transfusions, autotransfusions, and failure to locate a definitive source of bleeding during 2 separate surgeries. ε-Aminocaproic acid treatment was initiated and was associated with rapid clinical improvement and diminished fibrinolysis based on a modified plasma-based thromboelastogram. NEW OR UNIQUE INFORMATION PROVIDED: This report describes thromboelastographic evidence of inhibition of fibrinolysis after ε-aminocaproic acid administration in a dog with suspected acute traumatic coagulopathy. Thromboelastrography may be useful in monitoring therapy with antifibrinolytic drugs.

Metabolism, swimming performance, and tissue biochemistry of high desert redband trout (Oncorhynchus mykiss ssp.): evidence for phenotypic differences in physiological function.

Redband trout (Oncorhynchus mykiss ssp.) in southeastern Oregon inhabit high-elevation streams that exhibit extreme variability in seasonal flow and diel water temperature. Given the strong influence and potential limitations exerted by temperature on fish physiology, we were interested in how acute temperature change and thermal history influenced the physiological capabilities and biochemical characteristics of these trout. To this end, we studied wild redband trout inhabiting two streams with different thermal profiles by measuring (1) critical swimming speed (U(crit)) and oxygen consumption in the field at 12 degrees and 24 degrees C; (2) biochemical indices of energy metabolism in the heart, axial white skeletal muscle, and blood; and (3) temperature preference in a laboratory thermal gradient. Further, we also examined genetic and morphological characteristics of fish from these two streams. At 12 degrees C, maximum metabolic rate (Mo2max) and metabolic power were greater in Little Blitzen redband trout as compared with those from Bridge Creek (by 37% and 32%, respectively). Conversely, Bridge Creek and Little Blitzen trout had similar values for Mo2max and metabolic power at 24 degrees C. The U(crit) of Little Blitzen trout was similar at the two temperatures (61+/-3 vs. 57+/-4 cm s(-1)). However, the U(crit) for Bridge Creek trout increased from 62+/-3 cm s(-1) to 75+/-3 cm s(-1) when water temperature was raised from 12 degrees to 24 degrees C, and the U(crit) value at 24 degrees C was significantly greater than for Little Blitzen fish. Cost of transport was lower for Bridge Creek trout at both 12 degrees and 24 degrees C, indicating that these trout swim more efficiently than those from the Little Blitzen. Possible explanations for the greater metabolic power of Little Blitzen redband trout at 12 degrees C include increased relative ventricular mass (27%) and an elevation in epaxial white muscle citrate synthase activity (by 72%). Bridge Creek trout had 50% higher lactate dehydrogenase activity in white muscle and presumably a greater potential for anaerobic metabolism. Both populations exhibited a preferred temperature of approximately 13 degrees C and identical mitochondrial haplotypes and p53 gene allele frequencies. However, Bridge Creek trout had a more robust body form, with a relatively larger head and a deeper body and caudal peduncle. In summary, despite the short distance ( approximately 10 km) and genotypic similarity between study streams, our results indicate that phenotypic reorganization of anatomical characteristics, swimming ability at environmentally pertinent temperatures and white axial muscle ATP-producing pathways occurs in redband trout.