Comparison of indirect computed tomographic lymphography and near-infrared fluorescence sentinel lymph node mapping for integumentary canine mast cell tumors.

OBJECTIVE: To compare the independent and combined use of indirect computed tomographic lymphography (ICTL) and near-infrared fluorescence (NIRF) for sentinel lymph node (SLN) mapping in dogs with integumentary mast cell tumors (MCT) and report the metastatic LN rate. STUDY DESIGN: Prospective clinical study. ANIMALS: Twenty client-owned dogs. METHODS: Dogs underwent preoperative ICTL, then intraoperative NIRF SLN mapping and excision of the anatomic lymph node (ALN) and/or SLN, and primary MCT. Technique agreement was complete if the same SLN was detected, and partial if the same SLN was detected along with additional SLN. No agreement occurred if the techniques detected different or no SLN. MCT were graded using two- and three-tier schemes, and LN were graded from HN0-3; HN2-3 were considered metastatic. RESULTS: Complete, partial, and no agreement between ICTL and NIRF was seen in 8/20 (40%), 8/20 (40%), and 4/20 (20%) dogs, respectively. Detection of ICTL-SLN and NIRF-SLN failed in 1/20 (5%) and 4/20 (20%), respectively. Tumors were grade II/low-grade in 19/20 (95%) and grade III/high-grade in 1/20 (5%) dogs. Nineteen out of 20 (95%) dogs had HN2-3 LN. CONCLUSIONS: Technique agreement of at least one SLN was seen in 16/20 (80%) dogs. Although most MCT were classified as intermediate to low grade, LN metastases were commonly detected. CLINICAL SIGNIFICANCE: Combining ICTL and NIRF for MCT SLN mapping yields high SLN detection rates. Lymph node metastasis may be more common than previously reported for intermediate to low grade MCT.

Rapport de cas Mononuclear pleocytosis and meningoencephalitis caused by Listeria monocytogenes in an adult horse.

Clinical disease caused by infection with Listeria monocytogenes is rare in adult horses, and there is a paucity of ante-mortem clinicopathologic changes for this species reported in the literature. Confirmatory diagnosis is difficult and often requires post-mortem sampling of the brainstem. This report details a case of meningoencephalitis caused by Listeria monocytogenes in an adult American quarter horse gelding presenting with central neurologic signs. Pre-mortem analysis of the cerebrospinal fluid revealed a mononuclear, primarily lymphocytic, pleocytosis, which is a reported finding in other species with listeriosis. Post-mortem histopathologic changes of the brainstem were characteristic of listeriosis, and infection was confirmed with immunohistochemical labeling and bacterial culture. Key clinical message: Listeriosis should be included as a differential diagnosis in neurologic horses with mononuclear pleocytosis identified on cerebrospinal fluid analysis.

Pléocytose mononucléaire et méningo-encéphalite causées par Listeria monocytogenes chez un cheval adulte. La maladie clinique causée par une infection à L. monocytogenes est rare chez les chevaux adultes, et il y a peu de changements clinico-pathologiques ante-mortem rapportés dans la littérature pour cette espèce. Le diagnostic de confirmation est difficile et nécessite souvent un prélèvement post-mortem du tronc cérébral. Ce rapport détaille un cas de méningo-encéphalite causée par L. monocytogenes chez un hongre quarter horse américain adulte présentant des signes neurologiques centraux. L'analyse pré-mortem du liquide céphalo-rachidien a révélé une pléocytose mononucléaire, principalement lymphocytaire, qui est une trouvaille rapportée chez d'autres espèces atteintes de listériose. Les modifications histopathologiques post-mortem du tronc cérébral étaient caractéristiques de la listériose et l'infection a été confirmée par un marquage immunohistochimique et une culture bactérienne.Message clinique clé :La listériose doit être incluse comme diagnostic différentiel chez les chevaux avec signes neurologiques présentant une pléocytose mononucléaire identifiée lors de l'analyse du liquide céphalo-rachidien.(Traduit par Dr Serge Messier).

Investigating the Effects of Error Management Training versus Error Avoidance Training on the Performance of Veterinary Students Learning to Tie Surgical Knots.

Although errors can be a powerful impetus for learning, conventional pedagogy often emphasizes error-avoidance strategies that reward correct answers and disfavor mistakes. Error management training (EMT) takes an explicitly positive approach to errors, using them to create an active and self-directed learning environment. Using a surgical knot-tying model, we aimed to determine the efficacy of EMT among veterinary students with no prior surgical experience. We hypothesized that EMT would result in improved performance in unfamiliar scenarios (adaptive transfer) compared with an error-avoidance method. In this prospective double-blinded study, 42 students were equally divided between error avoidance training (EAT) and EMT groups. Performance in instrument- and hand-tied knots was evaluated for technique, time, number of attempts, and, when applicable, knot-leaking pressure. All participants demonstrated significant improvement between a pre-test and an analogous test 48 hours after training for all six outcomes (Wilcoxon matched pairs; two-tailed ps ≤ .013). An adaptive transfer test found no significant differences between EMT and EAT at 48 hours (ps ≥ .053). All participants demonstrated a significant performance decline in six of eight outcomes at 7 weeks post-training (ps ≤ .021). This decline was not significant for four of six EMT outcomes yet significant for five of six EAT outcomes. These data suggest that students trained in both EMT and EAT experience comparable gains in short-term performance, including adaptive transfer. Compared with EAT, EMT may help attenuate performance decline after a sustained period of quiescence. Educators may consider actively incorporating EMT into veterinary curricula.

Long-term outcomes of dogs undergoing surgical resection of mast cell tumors and soft tissue sarcomas: A prospective 2-year-long study.

OBJECTIVE: Report clinical outcomes of dogs with surgically excised mast cell tumors (MCT) and soft tissue sarcomas (STS). STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Fifty-three dogs with 52 MCT (50 low grade, 2 high grade) and 19 STS (12 grade I, 6 grade II, 1 grade III). METHODS: All dogs were examined at 3, 6, 12, 18, and 24 months postoperatively, with cytologic or histopathologic evaluation of suspected local recurrences. Dogs euthanized because of study tumor-related causes underwent necropsy. RESULTS: Median intraoperative margins were 20 mm and 30 mm wide for MCT and STS, respectively, with 1 fascial plane resected en bloc. The narrowest histologic tumor-free margins measured <1 mm in 21 of 52 (40%) MCT and 7 of 19 (37%) STS. All dogs were followed for 24 months. Two of 50 (4%) low-grade MCT were diagnosed, with local recurrence 181 and 265 days postoperatively. Two of 36 (6%) dogs with low-grade MCT developed visceral metastasis 181 and 730 days postoperatively. One of 2 dogs with high-grade MCT developed local recurrence 115 days postoperatively. No local recurrence or metastasis was diagnosed after excision of 19 STS. CONCLUSION: Local recurrence rates among predominantly low- to intermediate-grade MCT and STS were low, despite a high prevalence of histologic tumor-free margins <1 mm. Surgical recommendations for high-grade tumors cannot be extrapolated from this population. CLINICAL SIGNIFICANCE: Surgeons should seek to achieve microscopically complete excision for MCT and STS while minimizing patient morbidity and considering limitations of histopathology in predicting outcomes.

Inter-Institutional Collaboration for the Development of a Local Peer Observation Process to Enhance Teaching.

Local peer observation of teaching is considered an important mechanism for instructors to improve the quality and effectiveness of their teaching, but there is an absence of uniformity to establish a best practice for this process in veterinary curricula. The Regional Teaching Academy (RTA) of the Consortium of Western Colleges of Veterinary Medicine is comprised of educational advocates from five western veterinary colleges with a common goal of enhancing the quality and effectiveness of education in veterinary medical curricula. Members of the RTA recognized this deficit in best practices for local peer observation (LPO) and formed a working group called "Local Peer Observation of Teaching." The goal was to meet a critical need for the enhancement of individual teaching skills by using a scholarly approach to develop robust methods for peer observation of teaching. Two rubric-based instruments were developed: one for large-group/didactic settings, and the second for small-group/clinical settings. Each is accompanied by pre- and post-observation worksheets which are considered instrumental to success. Results of a qualitative survey of instrument users' experiences are shared. Both observers and observees view the experiential learning from faculty peer colleagues very positively and the meaningful feedback is appreciated and incorporated by observees. Suggestions for implementation of the peer observation process are discussed, considering strengths and challenges. The purpose of this article is to describe in depth, the development process and output of the efforts of the Local Peer Observation of Teaching working group as a potential best practice guideline for peer observation.

Reductions in margin length after excision of grade II mast cell tumors and grade I and II soft tissue sarcomas in dogs.

OBJECTIVE: Quantify changes in the circumferential lengths of surgical margins of resected canine mast cell tumors (MCT) and soft tissue sarcomas (STS) between the time of collection and histopathology. STUDY DESIGN: Prospective, hypothesis-driven, clinical study. SAMPLE POPULATION: Two hundred and thirty-seven margins from 69 excised tumors (50 MCT and 19 STS) in 51 client-owned dogs. METHODS: The lengths of surgical margins were recorded (eg, cranial, caudal, dorsal, and ventral) for each tumor at 5 time points: intraoperatively (in vivo), immediately after excision (ex vivo), after formalin fixation (postfixation), once mounted on glass slides (subgross), and as histologically tumor-free margins (HTFMs). RESULTS: Compared to in vivo dimensions, the length of surgical margins at each processing step (ie, ex vivo, postfixation, subgross, and HTFM) was reduced by a median of 3.0, 5.0, 6.0, and 8.8 mm for MCT; 2.5, 2.0, 5.0, and 5.0 mm for STS. All processing steps resulted in significant reductions among MCT samples (P < .0001), except between postfixation vs subgross, and for STS samples (P < .0001), except between ex vivo vs postfixation and subgross vs HTFM. The maximum reduction in the total length of margins (from in vivo to HTFM) was 29.6 and 24.2 mm for MCT and STS, respectively. CONCLUSION: Surgical margin length reductions occur due to a combination of physical factors (eg, tissue elasticity, myofibril contraction, and histologic processing) and biological factors (eg, microscopic tumor infiltration into the grossly normal surgical margin). CLINICAL SIGNIFICANCE: These data provide information relevant to evidence-based surgical planning and may influence patient morbidity in the most commonly encountered cutaneous malignancies of dogs.

Shaved margin histopathology and imprint cytology for assessment of excision in canine mast cell tumors and soft tissue sarcomas.

OBJECTIVE: To determine the feasibility and agreement of margin assessment by imprint cytology, shaved margin histopathology, and radial section histopathology in canine cutaneous and subcutaneous mast cell tumors (MCT) and soft tissue sarcomas (STS). STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Three hundred and forty margins from 72 excised tumors (52 MCT and 20 STS) in 54 client-owned dogs. METHODS: Imprint cytology samples were acquired by pressing glass slides to the cut surgical margin of the freshly excised surgical specimen. Shaved margin samples were obtained from the patient wound bed using a scalpel immediately prior to closure. Radial section histopathology was performed as part of routine histopathologic processing. All margins were assessed as either positive or negative for presence of tumor cells at the surgical margin. Agreement among methods was calculated using Fleiss Kappa coefficients and an association of method, margin direction, and tumor type with positive margin status was evaluated using a general linear mixed model. RESULTS: Positive margin detection rates differed for MCT (imprint cytology 21%, radial section histopathology 9%, and shaved margin histopathology 3%; P < .0001) but not for STS. Intermethod agreement was poor (Fleiss Kappa = 0.051 and 0.176 for MCT and STS, respectively). Margin direction did not influence margin status for either tumor type. CONCLUSION: Imprint cytology and shaved margin histopathology are feasible, but their results are frequently disparate from routine radial section histopathology. Future studies are needed to evaluate the correlation of each method with local recurrence rates.

The effect of agility exercise on eicosanoid excretion, oxidant status, and plasma lactate in dogs.

BACKGROUND: The objective was to determine the effects of agility exercise on dogs of different skill levels with respect to urinary eicosanoids, urinary 15F2t-isoprostane (lipid peroxidation marker) and hematological/biochemical changes in plasma. Fifteen adult dogs had blood and urine samples obtained prior to, immediately and 4-hours following an agility exercise. RESULTS: Hematocrit, red blood cells (RBC), albumin, and hemoglobin increased following exercise, with greatest increases correlating to increased skill group (novice, intermediate, masters); at 4-hours post-exercise, hematocrit, RBC, and hemoglobin were decreased. Phosphorus increased following exercise with the greatest increase in novice and intermediates. Plasma lactate increased 3.6-fold in masters, 3.2-fold in intermediates, and 1.2-fold in novice dogs. Urine thromboxane B2 (TXB2) more than tripled 4-hours post-exercise while 6-keto prostaglandin F1α (PGF1α, prostacyclin metabolite), prostaglandin E2 metabolites (13,14-dihydro-15-keto-prostaglandin A2 and 13,14-dihydro-15-keto-prostaglandin E2), and 13,14-dihydro-15-keto prostaglandin F2α were unaffected as determined by a competitive enzyme immunoassay and standardized by division with urine creatinine. Urine 15F2t-isoprostane increased insignificantly. CONCLUSIONS: Alterations in the plasma post-exercise were likely due to hemoconcentration from insensible water loss, splenic contraction and sympathetic stimulation while 4-hours later autohemodilution reduced RBC parameters. Elevations in plasma lactate and urinary TXB2 correlated with advanced skill level/speed of the dogs.

Putative Malassezia dermatitis in six goats.

Histopathology submissions from 28 goats with dermatological disease were identified in an archival search of pathology files. Microscopic sections of skin biopsy specimens were examined for the presence of Malassezia spp. organisms. Six cases with many Malassezia yeasts were identified histopathologically. Based on the extent of clinical disease, three cases were regarded as localized and three were generalized infections. Clinical findings included alopecia with dry seborrhoea (four cases), greasy seborrhoea (one case), and no clinical findings specific to localized Malassezia infection when concurrent bacterial infection was present (one case). Mild pruritus was reported in two cases of generalized infection. No breed predilection was apparent. Three cases were male and three were female. Malassezia dermatitis occurred in goats from 10 months to 13 years of age. Three of six cases had concurrent bacterial infection. Skin lesions resolved following topical antifungal therapy in the two goats that were treated. Histopathological findings in all cases were severe follicular and epidermal orthokeratotic hyperkeratosis with minimal epithelial change and mild superficial perivascular to interstitial nonsuppurative inflammation. Numerous budding yeasts were visible within the stratum corneum of all cases; however, Malassezia was not isolated in the three cases in which culture was attempted. Based upon these findings, the authors suggest that the diagnosis Malassezia dermatitis in goats is most likely to be made by cytological examination of skin impressions or by examination of skin biopsy samples.

Clinical relevance of splenic nodules or heterogeneous splenic parenchyma assessed by cytologic evaluation of fine-needle samples in 125 dogs (2011-2015).

BACKGROUND: Splenic nodules and heterogeneous parenchyma are seen frequently in abdominal ultrasound examinations of dogs, but the clinical importance of these lesions remains unclear. OBJECTIVES: To determine whether specific ultrasonographic findings correlate with clinically relevant cytologic diagnoses and determine what sonographic features are correlated with these diagnoses. Another objective was to develop a scoring rubric to help clinicians make decisions on whether or not certain ultasonographic findings of the spleen warrant evaluation by fine-needle cytology. ANIMALS: One-hundred twenty-five adult client-owned dogs with ultrasonographically identified splenic nodules, heterogeneous parenchyma, or both. METHODS: Medical records were retrospectively searched for ultrasound-guided splenic fine-needle cytology reports. Ultrasonographic images were assessed for nodule number, size, echogenicity and distal enhancement, degree of splenic heterogeneity, and peritoneal fluid. Dogs were divided into 2 groups: those with clinically important or clinically irrelevant cytologic findings. Potentially useful and discriminatory ultrasonographic findings were identified by statistical analysis, and the most useful findings were used to generate the scoring rubric. RESULTS: The clinically important group included 25 of 125 dogs (22 malignancies, 3 suppurative inflammation). Splenic nodules 1-2 cm in diameter, peritoneal fluid, and >1 targetoid nodule were associated with clinically important cytologic findings. Receiver operator characteristic analysis showed that the scoring rubric was useful for identifying dogs in the clinically important group. CONCLUSIONS AND CLINICAL IMPORTANCE: Splenic fine-needle cytologic findings identified a clinically relevant diagnosis in 20% of dogs, and larger nodule size, number of targetoid lesions, and presence of peritoneal fluid increase the likelihood of detection of clinically important disease.

Clinical evaluation of a benchtop dry chemistry analyzer for measurement of ammonium concentrations in canine plasma samples.

OBJECTIVE To evaluate the clinical performance of a veterinary benchtop dry chemistry analyzer for measurement of plasma ammonium concentrations in dogs by comparing results with those obtained by a reference standard test method. DESIGN Prospective evaluation study. SAMPLE 32 blood samples from 30 dogs (16 with and 14 without suspected hepatobiliary disease). PROCEDURES Blood samples were collected by jugular venipuncture. A veterinary benchtop dry chemistry analyzer and a reference standard (enzymatic) test method were used to measure ammonium concentrations in plasma collected from heparinized whole blood. Bland-Altman plots were used to assess intermethod agreement. Results were compared by linear regression, and correlation was calculated by the Pearson method. Samples were classified as having high or normal ammonium concentrations on the basis of cutoff data for the relevant test method; results were compared between methods to evaluate diagnostic agreement. RESULTS 31 of 32 (97%) samples were classified correctly with the benchtop analyzer; 1 sample with a high ammonium concentration was classified as having a normal value (ie, false-negative result) by this method. A strong positive correlation (r2 = 0.989) was found between methods, with constant, proportional, negative bias for benchtop analyzer results. The interassay coefficient of variation (ie, precision) for measurement of an internal standard with the benchtop analyzer was 2.74% (n = 20 repetitions). CONCLUSIONS AND CLINICAL RELEVANCE The dry chemistry analyzer used in the study had acceptable clinical performance for detection of high versus normal ammonium concentrations in canine plasma, indicating the method can be used to aid diagnosis in dogs with suspected hepatobiliary disease.

A case of canine high-grade T-cell lymphoma immunophenotypically consistent with T-zone lymphoma.

A 9-year-old spayed female Curly Coated Retriever was referred for evaluation of generalized peripheral lymphadenomegaly. The dog was clinically healthy on presentation with no anomalies detected on complete blood count, serum biochemistry, urinalysis, or three-view thoracic radiographs. Fine-needle aspiration (FNA) and cytology of the peripheral lymph nodes were consistent with lymphoma with an intermediate-sized lymphoid population. Flow cytometry of peripheral lymph nodes was consistent with a homogeneous population of CD4+ T cells that had lost expression of the pan-leukocyte antigen CD45. Variable expression of CD21, CD25, and class II major histocompatibility complex (MHC) were also noted. This was considered consistent with T-zone lymphoma (TZL), although the T cells were noted to be larger than usual based on flow cytometry. Due to the suspected indolent nature of this patient's disease and clinical progression, a careful monitoring approach was initially discussed with the owner. However, additional diagnostic testing was performed to confirm the diagnosis. Bone marrow cytology did not show any significant anomalies. The largest lymph node (left mandibular) was extirpated and submitted for histopathology. Based on the lymph node architecture, cellular features, and high mitotic activity, an unexpected diagnosis of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) was made. The dog was started on CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy. This case illustrates the limitations of using flow cytometry as the sole means of diagnosing TZL and highlights the importance of using complementary tests when subtyping canine lymphoma, which is significant when considering a patient's treatment plan and prognosis.

Spurious Results in Mineral and Electrolyte Analysis.

Assessment of health status and the course of treatment of patients are often determined by results obtained from analysis of blood parameters. Errors in results can occur and cause inappropriate interpretation of laboratory data and, therefore, disease states. Electrolytes and minerals are particularly prone to spurious results; therefore, it is critical that factors influencing inappropriate resulting be recognized, and steps taken to minimize them.

Cutaneous metastasis of primary appendicular osteosarcoma in a dog.

A 6-year-old, neutered male Rottweiler was presented to the University of Illinois Veterinary Teaching Hospital because of a lytic bone lesion involving the distal portion of the right radius and possible pulmonary metastases on thoracic radiographs. Results of serum biochemical analysis were unremarkable. Aspiration and cytologic examination of the bone lesion indicated likely sarcoma with reactive bone. Cutaneous masses were found on the left thigh, interscapular region, and dorsal lumbar region, 4 weeks after initial presentation. Neoplastic spindle cells were found in aspirates from 2 of the masses. The neoplastic cells stained positive for alkaline phosphatase activity using cytochemistry. Re-evaluation of serum biochemical values at this time revealed a marked increase in alkaline phosphatase activity (413 U/L, reference interval 12-110 U/L) compared with the initial value (26 U/L). Due to progressive disease, the dog was euthanized and a necropsy was performed. Histologic findings included primary osteosarcoma of the distal portion of the right radius, with metastases in the lungs, spleen, left fourth and fifth ribs, soft tissue of the right medial thigh, and T1-T3/interscapular region. Cutaneous metastasis of primary appendicular osteosarcoma has been reported rarely in animals and humans. Increased serum alkaline phosphatase activity may be a potential indicator of poor prognosis for this neoplasm.

Biphenotypic B-cell lymphoma in 2 cats.

The clinical and pathologic features of biphenotypic B-cell lymphoma in 2 cats are reported. Clinical presentation varied from multiple cutaneous masses identified on the thigh in one cat to signs of lethargy from acute hemorrhage due to neoplastic infiltration of one kidney in the other. Cytology and histopathology confirmed round cell neoplasia in both cats and immunochemical staining demonstrated expression of both B- and T-lymphocyte markers by the neoplastic cells in both animals. In PCR analysis of antigen receptor gene rearrangement, clonal rearrangement of B-cell receptor genes and polyclonal T-cell receptor gene rearrangement were demonstrated in both lymphomas. These findings were consistent with a diagnosis of B-cell lymphoma with aberrant CD3 expression in both cases. Clinical progression of disease post diagnosis was rapid in both cats, suggesting a poor prognosis for this lymphoma type. Although bigenotypic receptor rearrangement of lymphoma cells appears relatively common, this is the first known report of actual biphenotypic lymphoma in cats.

Effects of low and high dose intraarticular tiludronate on synovial fluid and clinical variables in healthy horses-a preliminary investigation.

To determine effects of intraarticularly administered tiludronate on articular cartilage in vivo, eight healthy horses were injected once with tiludronate (low dose tiludronate [LDT] 0.017 mg, n = 4; high dose tiludronate [HDT] 50 mg, n = 4) into one middle carpal joint and with saline into the contralateral joint. Arthrocentesis of both middle carpal joints was performed pre-treatment, and 10 min, 24 h, 48 h, 7 and 14 days after treatment. Synovial nucleated cell counts and total solids, tiludronate, sulfated glycosaminoglycan (sGAG), chondroitin sulfate 846 epitope (CS-846, a measure of aggrecan synthesis), and collagen type II cleavage neoepitope (C2C) concentrations were determined. Histologic analysis of joint tissues and sGAG quantitation in cartilage was performed at 14 days in HDT horses. Data were analyzed by repeated measures non-parametric ANOVA and Wilcoxon signed-rank test. High dose tiludronate administration produced synovial fluid tiludronate concentrations of 2,677,500 ng/mL, exceeding concentrations that were safe for cartilage in vitro, and LDT administration produced synovial fluid concentrations of 1,353 ng/mL, remaining below concentrations considered potentially detrimental to cartilage. With HDT, synovial fluid total solids concentration was higher at 24 h and 7 days and sGAG concentration was higher at 48 h, compared to control joints. Synovial fluid CS-846 concentration was increased over pre-treatment values in HDT control but not in HDT treated joints at 24 and 48 h. All joints (HDT and LDT control and treated) showed a temporary decrease in synovial fluid C2C concentration, compared to pre-treatment values. Histologic features of articular cartilage and synovial membrane did not differ between HDT treated and control joints. High dose tiludronate treatment caused a transient increase in synovial total solids and temporarily increased proteoglycan degradation in cartilage. Although clinical significance of these changes are questionable, as they did not result in articular cartilage damage, further investigation of the safety of intraarticular HDT in a larger number of horses is warranted.