Detection of Anaplasma phagocytophilum in an inflammatory pericardial effusion of a dog.

An 11-year-old female spayed German Wirehaired Pointer with a 1-week history of lethargy, hyporexia, diarrhea, and coughing presented with pericardial effusion causing cardiac tamponade. An echocardiogram revealed no structural cause for pericardial effusion. The pericardial effusion was an exudate with mixed macrophagic and neutrophilic inflammation. Morulae occasionally were found within neutrophils. The pericardial fluid and blood were qPCR and cPCR positive for Anaplasma phagocytophilum (NC State University, Vector-borne Disease Diagnostic Laboratory, Raleigh, NC). The dog's blood was negative by ELISA (Vetscan Flex4 Rapid Test, Zoetis, Parsippany, NJ) for A. phagocytophilum antibodies at initial presentation and subsequently positive (SNAP4DxPlus, IDEXX, Westbrook, ME) 7 days later. After pericardiocentesis and administration of doxycycline (5 mg/kg PO q12h for 14 days), a repeat echocardiogram performed 1 month later showed no recurrence of pericardial effusion.

Seminoperitoneum in a Dog with a History of a Vasectomy: Case Report.

An 8 yr old male German shorthaired pointer was presented on July 4, 2022, for acute abdominal and testicular pain. The dog was vasectomized at an unknown age under the care of his previous owners. The dog had an enlarged, painful left testis, scrotal edema, and an enlarged, nonpainful prostate. Abdominal ultrasound revealed mild peritoneal and retroperitoneal effusion, orchiepididymitis, enlarged ductus deferentes and testicles, and suspected benign prostatic hyperplasia versus prostatitis. Peritoneal effusion cytology revealed seminoperitoneum with marked neutrophilic inflammation. Peritoneal effusion aerobic culture and Brucella canis rapid slide agglutination test were negative. The dog was hospitalized overnight with IV antibiotic therapy and analgesics. The following day, the dog's abdominal pain, testicular pain, and scrotal edema were resolved. The dog was discharged and castrated after completion of antibiotic therapy and complete resolution of clinical signs. Testicular histopathology results were not available. Seminoperitoneum is uncommon in dogs and is a rare diagnosis for dogs with acute abdominal pain. This is the second known reported case of a seminoperitoneum in a vasectomized dog.

Long-term assessment of relationships between changing environmental conditions and the physiology of southern Beaufort Sea polar bears (Ursus maritimus).

Climate change is influencing polar bear (Ursus maritimus) habitat, diet, and behavior but the effects of these changes on their physiology is not well understood. Blood-based biomarkers are used to assess the physiologic health of individuals but their usefulness for evaluating population health, especially as it relates to changing environmental conditions, has rarely been explored. We describe links between environmental conditions and physiologic functions of southern Beaufort Sea polar bears using data from blood samples collected from 1984 to 2018, a period marked by extensive environmental change. We evaluated associations between 13 physiologic biomarkers and circumpolar (Arctic oscillation index) and regional (wind patterns and ice-free days) environmental metrics and seasonal and demographic co-variates (age, sex, season, and year) known to affect polar bear ecology. We observed signs of dysregulation of water balance in polar bears following years with a lower annual Arctic oscillation index. In addition, liver enzyme values increased over time, which is suggestive of potential hepatocyte damage as the Arctic has warmed. Biomarkers of immune function increased with regional-scale wind patterns and the number of ice-free days over the Beaufort Sea continental shelf and were lower in years with a lower winter Arctic oscillation index, suggesting an increased allocation of energetic resources for immune processes under these conditions. We propose that the variation in polar bear immune and metabolic function is likely indicative of physiologic plasticity, a response that allows polar bears to remain in homeostasis even as they experience changes in nutrition and habitat in response to changing environments.

The Clumsy Horse: A Professional Development Tool for Facilitators of Self-Directed, Case-Based Learning.

Introduction: With the constant evolution of science and advancing technology, future physicians must learn to navigate an ever-changing health care environment by continuous learning throughout their professional careers. Lifelong, self-directed learning is a critical component of medical education to ensure future physicians are adept at identifying knowledge gaps and seeking, analyzing, and communicating new information. To train faculty who teach case-based, self-directed learning, we designed the Clumsy Horse Case. Methods: The Clumsy Horse Case was created as part of a faculty development program for facilitators of a new case-based, self-directed curriculum known as Patient-Centered Education (PaCE) Cases. An unfamiliar veterinary medicine case was designed to level the playing field for faculty from different specialty areas in order to provide an authentic self-directed learning experience. To determine effectiveness, faculty participants completed a standardized eight-question evaluation survey after the Clumsy Horse Case session, and facilitators received student feedback at the end of each semester via a standard faculty evaluation form. Results: Student ratings indicated that faculty were adequately prepared to be effective facilitators. The Clumsy Horse Case was an integral part of facilitator preparation and provided an engaging learning experience for over 60 faculty. Survey ratings and comments from faculty participants indicated a high level of engagement and satisfaction with the learning experience. Discussion: The Clumsy Horse Case is generalizable for developing faculty in any curriculum with a case-based, self-directed learning component. It can be modified to fit any school's curriculum and integrated into a professional development program.

Grey eosinophils in a Miniature Schnauzer with a poorly differentiated mast cell tumor.

A 10-year-old female spayed Miniature Schnauzer was presented for investigation of an intra-nasal mass. The mass was diagnosed by histopathologic examination as an undifferentiated round cell neoplasm with an infiltrate of segmented leukocytes, interpreted as neutrophilic inflammation. The mass was treated with palliative radiation and systemic chemotherapy due to the presence of regional lymph node metastasis. During subsequent monitoring over several months, the peripheral leukocyte concentration was repeatedly within reference intervals to slightly increased with low numbers of toxic neutrophils. Four months after the initial diagnosis, there was a significant leukocytosis of 66 100 cells/µL, and 39 700 cells/µL of the leukocytes had variably mature, lobulated, and hypolobulated nuclei, and grey cytoplasm with clear vacuoles, resembling grey eosinophils. To further characterize these cells, peripheral blood smears from the patient and a canine control with eosinophilia were stained for alkaline phosphatase (AP), peroxidase, and esterase activities, and with Luxol fast blue (LFB). Histopathologic sections of the nasal mass were stained with LFB and immunohistochemically for tryptase. On blood smears, the cytoplasm of the suspected grey eosinophils stained for AP and granules stained with LFB confirmed that there was an eosinophilic lineage. Peroxidase staining was weak, and esterase staining was absent. On histopathologic sections from the nasal mass, the segmented leukocytes contained LFB-staining granules, indicating an eosinophilic infiltrate was present. Neoplastic cells expressed tryptase, which confirms a mast cell lineage. Our findings suggest that grey eosinophils might be under-recognized and interpreted incorrectly as toxic neutrophils. This report expands the canine breeds in which these eosinophils have been identified.

Reference intervals for blood-based biochemical analytes of southern Beaufort Sea polar bears.

Accurate reference intervals (RIs) for commonly measured blood-based analytes are essential for health monitoring programmes. Baseline values for a panel of analytes can be used to monitor physiologic and pathophysiologic processes such as organ function, electrolyte balance and protein catabolism. Our reference population includes 651 serum samples from polar bears (Ursus maritimus) from the southern Beaufort Sea (SB) subpopulation sampled in Alaska, USA, between 1983 and 2016. To establish RI for 13 biochemical analytes, we defined specific criteria for characterizing the reference population and relevant subgroups. To account for differences in seasonal life history characteristics, we determined separate RI for the spring and fall seasons, when prey availability and energetic requirements of bears differ. We established RI for five subgroups in spring based on sex, age class and denning status, and three subgroups in fall based on sex and age class in females only. Alkaline phosphatase activities were twice as high in subadult as in adult polar bears in spring (z males = 4.08, P males < 0.001, z females = 3.90, P females < 0.001) and did not differ between seasons. Denning females had significantly higher glucose concentrations than non-denning females (z = 4.94, P < 0.001), possibly reflecting differences in energy expenditure during lactation. A total of 10 of the 13 analytes differed significantly between seasons in either males or females; however, the physiologic importance of these differences may be minimal. Establishing these RIs allows for temporal monitoring of polar bear health in the SB and may prove useful for assessing and monitoring additional polar bear subpopulations in a changing Arctic environment.

Neutrophil progenitor populations of rhesus macaques.

Captive-bred rhesus macaques of Indian origin represent one of the most important large animal models for infectious disease, solid organ transplantation, and stem cell research. There is a dearth of information defining hematopoietic development, including neutrophil leukocyte differentiation in this species using multicolor flow cytometry. In the current study, we sought to identify cell surface markers that delineate neutrophil progenitor populations with characteristic immunophenotypes. We defined four different postmitotic populations based on their CD11b and CD87 expression pattern, and further refined their immunophenotypes using CD32, CD64, lactoferrin, and myeloperoxidase as antigenic markers. The four subsets contained myelocyte, metamyelocyte, band, and segmented neutrophil populations. We compared our flow cytometry-based classification with the classical nuclear morphology-based classification. We found overlap of immunological phenotype between populations of different nuclear morphology and identified phenotypically different subsets within populations of similar nuclear morphology. We assessed the responsiveness of these populations to stimulatory signals, such as LPS, fMLP, or PMA, and demonstrated significant differences between human and rhesus macaque neutrophil progenitors. In this study, we provided evidence for species-specific features of granulopoiesis that ultimately manifested in the divergent immunophenotypes of the fully differentiated segmented neutrophils of humans and rhesus macaques. Additionally, we found functional markers that can be used to accurately quantify neutrophil progenitors by flow cytometry. Although these markers do not coincide with the classical nuclear-morphology-based grading, they enable us to perform functional studies monitoring immunophenotypic markers.

Method Comparison Using 2 Point-of-Care Meters and a Reference Analyzer for Measuring Blood Triglycerides in Psittacine Birds.

Female reproductive disorders, such as chronic egg laying, are common in captive psittacine birds. While a disease diagnosis related to reproductive disorders can often be accomplished by physical examination and diagnostic imaging, monitoring of the response to environmental modification and medical treatment is more challenging. Monitoring ideally would involve measurement of luteinizing hormone or estrogen to assess ovarian activity. However, the amount of blood required for hormone analysis is greater than the small sample size that one can collect from these birds. Additionally, the lack of reference intervals limits their use as a diagnostic tool. Because plasma triglyceride increases during sustained estrogen release from the ovary, it may be used as an alternative method for assessing ovarian activity in birds. Point-of-care (POC) analyzers for measuring lipids in human plasma use very small sample volumes and have been used for measuring triglycerides in animals, including chickens. The authors therefore performed a method comparison study with 2 POC analyzers and a reference analyzer and plasma and whole blood from psittacine birds to determine whether these meters are suitable for triglyceride measurement in a known population of psittacine birds. Correlation, Deming regression, and Bland-Altman analyses were used to assess performance, and the total observed error for each meter relative to the reference analyzer was calculated. One of the meters exhibited fair performance and, with species-specific reference intervals, is likely to be clinically useful for triglyceride measurement in psittacine birds. The other meter demonstrated poor performance with unacceptable error, and its use for this purpose is strongly discouraged.

Biomarker responses of Peromyscus leucopus exposed to lead and cadmium in the Southeast Missouri Lead Mining District.

Biomarker responses and histopathological lesions have been documented in laboratory mammals exposed to elevated concentrations of lead and cadmium. The exposure of white-footed mice (Peromyscus leucopus) to these metals and the potential associated toxic effects were examined at three contaminated sites in the Southeast Missouri Lead Mining District and at a reference site in MO, USA. Mice from the contaminated sites showed evidence of oxidative stress and reduced activity of red blood cell δ-aminolevulinic acid dehydratase (ALAD). Histological examinations of the liver and kidney, cytologic examination of blood smears, and biomarkers of lipid peroxidation and DNA damage failed to show indications of toxic effects from lead. The biomagnification factor of cadmium (hepatic concentration/soil concentration) at a site with a strongly acid soil was 44 times the average of the biomagnification factors at two sites with slightly alkaline soils. The elevated concentrations of cadmium in the mice did not cause observable toxicity, but were associated with about a 50% decrease in expected tissue lead concentrations and greater ALAD activity compared to the activity at the reference site. Lead was associated with a decrease in concentrations of hepatic glutathione and thiols, whereas cadmium was associated with an increase. In addition, to support risk assessment efforts, we developed linear regression models relating both tissue lead dosages (based on a previously published a laboratory study) and tissue lead concentrations in Peromyscus to soil lead concentrations.

Validation of 2 point-of-care meters for measuring triglycerides in chickens using whole blood and plasma.

Disorders of the avian reproductive tract are common, yet monitoring their resolution presents a diagnostic dilemma. Reproductive hormones such as luteinizing hormone or estrogen are the best reflection of reproductive status, but the required sample volumes and lack of reference intervals limit their clinical utility. An alternative analyte is blood triglyceride, the concentration of which rises markedly during sustained estrogen release from the ovary. Portable meters for measuring human blood triglyceride concentration offer the advantage of using minimal sample volumes, but these have not been validated for use in birds. We assessed the precision and accuracy of 2 portable meters for measuring blood triglyceride concentration in pooled whole blood and plasma from chickens ( n = 42), and performed method comparison using a reference analyzer and determined total error. Within-run repeatability was fair-to-excellent using whole blood and plasma (range: 2.5-11.5%), and between-run repeatability using plasma was similar (3.1-12.2%). The meters performed well in recovery and dilution studies in which almost all readings fell within the preset requirement of 75-125%. Correlations between each meter, using whole blood and plasma, and the reference analyzer, using plasma only, were high to very high (0.86-0.98). Bias determined by Bland-Altman analysis was similar between whole blood and plasma for each meter, yet markedly different between the meters. The calculated total observed error was consequently within our pre-set total allowable error of 25% for one meter but not the other, indicating the requirement for a meter-specific reference interval.

Defining colloid osmotic pressure and the relationship between blood proteins and colloid osmotic pressure in dairy cows and calves.

OBJECTIVE: To establish the reference interval for colloid osmotic pressure (COP) in neonatal and adult cattle and to investigate associations between COP and total protein, albumin, or globulin in the two populations sampled. DESIGN: Cross-sectional observational study. SETTING: Animals were sampled on commercial dairy farms in Southern Wisconsin, and samples were processed and analyzed in a clinical pathology laboratory at a university teaching hospital. ANIMALS: Forty adult lactating Holstein cows between 2 and 4 years of age and 40 healthy Holstein calves of both sexes between 2 and 7 days of age. INTERVENTIONS: Adult cows were sampled by coccygeal venipuncture into standard heparinized vacutainer tubes, calves were sampled by jugular venipuncture also into heparinized vacutainer tubes. MEASUREMENTS AND MAIN RESULTS: For adult cows, the mean COP was 22.52 mm Hg, with a standard deviation of 1.0. For calves, the mean COP was 19.6 mm Hg, with a standard deviation of 1.9. Good correlation was demonstrated in adults between COP and albumin concentrations (r(2) = 0.72) and between COP and both total protein concentration (r(2) = 0.74) and globulin (r(2) = 0.65) in calves. For adults, regression plots established best fit relationships of COP = 0.472 (albumin) + 6.49, whereas for calves, two regression equations could be described; COP = 0.305 (globulin) + 8.62, and 0.268 (total plasma protein) + 2.73. CONCLUSIONS: Suggested normal ranges (mean ± 2 standard deviations) for COP in adult lactating dairy cows and calves between 2 and 7 days of age were 21-25 mm Hg and 17-23 mm Hg, respectively.

Sarcocystid organisms found in bile from a dog with acute hepatitis: a case report and review of intestinal and hepatobiliary Sarcocystidae infections in dogs and cats.

Sarcocystidae is a family of coccidian protozoa from the phylum Apicomplexa that includes Toxoplasma, Neospora, Sarcocystis, Hammondia, and Besnoitia spp. All species undergo a 2-host sexual and asexual cycle. In the definitive host, replication is enteroepithelial, and infection is typically asymptomatic or less commonly causes mild diarrhea. Clinical disease is most frequently observed in the intermediate host, often as an aberrant infection, and is mostly associated with neurologic, muscular, or hepatic inflammation. Here, we review the literature regarding intestinal Sarcocystidae infections in dogs and cats, with emphasis on the life cycle stages and the available diagnostic assays and their limitations. We also report the diagnostic findings for an 11-year-old dog with acute neutrophilic hepatitis, biliary protozoa, and negative biliary culture. Although Toxoplasma and Neospora IgG titers were both high, PCR for these 2 organisms was negative for bile. The organisms were identified by 18S rDNA PCR as most consistent with Hammondia, either H heydorni or H triffittae. This is the first report of presumed Hammondia organisms being found in canine bile.

Transient cold agglutinins associated with Mycoplasma cynos pneumonia in a dog.

This report details a case of reversible cold agglutinins in a dog with Mycoplasma cynos pneumonia. An 11-month-old female spayed Rhodesian Ridgeback was presented for lethargy and cough. Thoracic radiographs revealed an alveolar pattern present bilaterally in the cranioventral lung lobes. Septic neutrophilic inflammation with suspected Mycoplasma sp. organisms was noted on cytologic examination of a trans-tracheal wash, and the dog was treated empirically with IV ampicillin/sulbactam and enrofloxacin pending culture results. Red blood cell agglutination was noted unexpectedly on several blood film reviews during hospitalization; however, the dog never developed clinical or laboratory evidence of hemolysis. Cold agglutinins were demonstrated based on the results of a saline dilution and cold agglutinin test that showed agglutination at 4°C but not at room temperature (21°C) or 37°C. Based on a positive culture for M cynos, the dog was treated for 8 weeks with oral enrofloxacin. After clinical and radiographic resolution of the pneumonia, repeated saline dilution and cold agglutinin tests of peripheral blood were negative at all temperatures. Reversible, asymptomatic cold agglutinins are common in human patients with mycoplasma pneumonia, but this is the first reported case in a dog.

Hematologic and biochemical reference intervals for adult Friesian horses from North America.

BACKGROUND: Established breed-specific reference intervals (RI) are an important tool for monitoring the health of horses. There is a lack of published work on breed-specific RI for Friesian horses. OBJECTIVES: The goal of this project was to determine hematologic and biochemical RI for Friesian horses residing in North America. METHODS: Strict inclusion and exclusion criteria were established for selection of reference subjects and for blood specimen collection and handling. Blood samples from 123 healthy, adult (range 3-18 years, median 8 years) Friesian horses of both sexes (70 mares, 45 geldings, and 8 stallions) were used to determine RI. Complete blood counts (CBC) and biochemistry profiles were performed on the Sysmex XT-2000iV hematology and Olympus AU400 biochemistry analyzers, respectively, at IDEXX Laboratories Inc. (Columbus, OH, USA). Results were analyzed using Reference Value Advisor. According to the guidelines of the ASVCP, nonparametric RI with 90% confidence intervals were determined. RESULTS: IDEXX equine RI are transferrable to Friesian horses for 30 of 36 analytes. Friesian-specific RI (medians) are recommended for the following variables: RBC 5.02-8.74 × 10(6) /µL (6.66), HCT 27-42% (34), HGB 9.0-14.3 g/dL (11.4), lactate dehydrogenase 299-866 U/L (493), direct bilirubin 0.3-0.7 mg/dL (0.5), and anion gap 7-18 mEq/L (12). CONCLUSIONS: The RI established in this study provide a useful baseline for the assessment of hematologic and biochemical data in Friesian horses residing in North America.

Differentiating between analytical and diagnostic performance evaluation with a focus on the method comparison study and identification of bias.

Prior to introduction of a new method to the diagnostic laboratory, analytical performance must be validated to ensure operation within the manufacturer's specifications and/or within predetermined quality requirements. In addition, the new method may require diagnostic performance assessment to ensure it differentiates between diseased and nondiseased individuals as intended. These 2 phases of assessment, while complementary, are not equivalent and require a different set of experiments, statistical analyses, and interpretation. Studies of analytical performance typically include a method comparison experiment, the purpose of which is to identify bias (inaccuracy) of the "test" (or "index") method (new method) relative to a "comparative method" (established method). Analysis of method comparison data is facilitated by commercial software programs that present the statistical significance of identified bias; however, the clinical relevance of any bias also should be considered. Studies of diagnostic performance should not be pursued until analytical performance is fully characterized and may not be required for well-established tests or for those for which results are nonspecific (ie, not referable to a specific disease or condition). Diagnostic performance assessment may include assessment of sensitivity, specificity, predictive values, odds ratios, and/or likelihood ratios. The purpose of this review is to clarify differences between the assessment of analytical and diagnostic performance, and to explore the method comparison study and bias assessment from a perspective not addressed in prior veterinary articles.

ASVCP reference interval guidelines: determination of de novo reference intervals in veterinary species and other related topics.

Reference intervals (RI) are an integral component of laboratory diagnostic testing and clinical decision-making and represent estimated distributions of reference values (RV) from healthy populations of comparable individuals. Because decisions to pursue diagnoses or initiate treatment are often based on values falling outside RI, the collection and analysis of RV should be approached with diligence. This report is a condensation of the ASVCP 2011 consensus guidelines for determination of de novo RI in veterinary species, which mirror the 2008 Clinical Laboratory and Standards Institute (CLSI) recommendations, but with language and examples specific to veterinary species. Newer topics include robust methods for calculating RI from small sample sizes and procedures for outlier detection adapted to data quality. Because collecting sufficient reference samples is challenging, this document also provides recommendations for determining multicenter RI and for transference and validation of RI from other sources (eg, manufacturers). Advice for use and interpretation of subject-based RI is included, as these RI are an alternative to population-based RI when sample size or inter-individual variation is high. Finally, generation of decision limits, which distinguish between populations according to a predefined query (eg, diseased or non-diseased), is described. Adoption of these guidelines by the entire veterinary community will improve communication and dissemination of expected clinical laboratory values in a variety of animal species and will provide a template for publications on RI. This and other reports from the Quality Assurance and Laboratory Standards (QALS) committee are intended to promote quality laboratory practices in laboratories serving both clinical and research veterinarians.