Clinical ophthalmological diagnostic description of 10 healthy sugar gliders (Petaurus breviceps) and prevalence of ocular-related presentations in a larger hospital population.

OBJECTIVE: To provide reference values for ocular examination and diagnostics in ophthalmologically normal sugar gliders (Petaurus breviceps). To retrospectively determine the prevalence of ocular diseases in sugar gliders presenting to a single institution. ANIMALS: Ten client owned and 106 previously evaluated sugar gliders. PROCEDURE: A descriptive study evaluated sugar gliders presented to Colorado State University's Avian, Exotics, and Zoological Medicine Service (CSU-AEZ) from August-2019 to January-2020. A complete ophthalmic examination including Schirmer tear test II (STT II), phenol red threat test (PRTT), intraocular pressure (IOP) via rebound tonometry, fluorescein, and rose bengal stain was performed under anesthesia. Conjunctival aerobic culture swabs and cytology were collected prior to ophthalmic evaluation. A retrospective review of medical records of sugar gliders presented to CSU-AEZ from 2008 to 2018 for ocular disease was performed. RESULTS: Mean values ± standard deviation for selected diagnostics included the following: STT II: 2.2 ± 6.7 mm/min; PRTT: 0 ± 0 mm/15 s; IOP: 12 ± 2.6 mm Hg. Fluorescein and rose bengal staining highlighted corneal abrasions secondary to tear testing. The three most common conjunctival bacterial isolates cultured were Staphylococcus spp. (3/20, 15%), Coryneform spp. (3/20, 15%), and unidentified Gram-positive cocci (3/20, 15%). Retrospective analysis revealed ocular diseases to be the third most common abnormality resulting in sugar glider presentations (13/106, 12.3%). CONCLUSION: This descriptive study gives reference values for IOP, conjunctival microbiology, and cytology for sugar gliders. STT II and PRTT provide little clinical value in sugar gliders. The retrospective study revealed that ocular abnormalities, often secondary to dental disease, are a common reason for presentation.

Bilateral Anterior Uveitis in a Northern Saw-whet Owl (Aegolius acadicus) With a Metastatic Pectoral Malignant Mesenchymoma.

A captive, adult, male northern saw-whet owl (Aegolius acadicus) was examined for blepharospasm of the left eye. The owl was diagnosed with bilateral anterior uveitis and a corneal ulceration in the left eye. It was treated with oral and topical nonsteroidal anti-inflammatory medications and a topical antibiotic. Multiple recheck examinations and medication adjustments were performed over the next 4 months, at the end of which time the bilateral anterior uveitis was controlled with a topical nonsteroidal anti-inflammatory applied 3 times per week to both eyes. The owl was re-examined 2 months later after 2 suspected neurologic episodes. On physical examination, the owl was quiet and had difficulty standing and ambulating. Five firm multilobular and immobile masses were identified overlying the pectoral muscle and sternum. Fine-needle aspiration from 1 mass revealed neoplastic cells consistent with a sarcoma. The owl was euthanatized. On the basis of results of histopathologic examination, the mass was diagnosed as a pleomorphic spindle cell sarcoma with features of rhabdomyosarcoma, liposarcoma, and osteosarcoma. Numerous tumor cells were immunopositive for myoglobin and desmin, indicating striated muscle origin. Although a metastatic lesion was present in 1 adrenal gland, lesions of inflammation or neoplasia were absent in either eye on histopathologic examination. This report describes an apparent ocular manifestation of systemic disease in an avian species with clinically diagnosed recurrent anterior uveitis.

Observational Study Design in Veterinary Pathology, Part 2: Methodology.

Observational studies are a basis for much of our knowledge of veterinary pathology, yet considerations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offered advice on planning and carrying out an observational study. Part 2 of the series focuses on methodology. Our general recommendations are to consider using already-validated methods, published guidelines, data from primary sources, and quantitative analyses. We discuss 3 common methods in pathology research-histopathologic scoring, immunohistochemistry, and polymerase chain reaction-to illustrate principles of method validation. Some aspects of quality control include use of clear objective grading criteria, validation of key reagents, assessing sample quality, determining specificity and sensitivity, use of technical and biologic negative and positive controls, blinding of investigators, approaches to minimizing operator-dependent variation, measuring technical variation, and consistency in analysis of the different study groups. We close by discussing approaches to increasing the rigor of observational studies by corroborating results with complementary methods, using sufficiently large numbers of study subjects, consideration of the data in light of similar published studies, replicating the results in a second study population, and critical analysis of the study findings.

Observational Study Design in Veterinary Pathology, Part 1: Study Design.

Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature. Investigators should recognize the importance of creativity, insight, and innovation in devising studies that solve problems and fill important gaps in knowledge. Studies should focus on specific and testable hypotheses, questions, or objectives. The methodology is developed to support these goals. We consider the merits and limitations of different types of analytic and descriptive studies, as well as of prospective vs retrospective enrollment. Investigators should define clear inclusion and exclusion criteria and select adequate numbers of study subjects, including careful selection of the most appropriate controls. Studies of causality must consider the temporal relationships between variables and the advantages of measuring incident cases rather than prevalent cases. Investigators must consider unique aspects of studies based on archived laboratory case material and take particular care to consider and mitigate the potential for selection bias and information bias. We close by discussing approaches to adding value and impact to observational studies. Part 2 of the series focuses on methodology and validation of methods.

Identification of three molecular and functional subtypes in canine hemangiosarcoma through gene expression profiling and progenitor cell characterization.

Canine hemangiosarcomas have been ascribed to an endothelial origin based on histologic appearance; however, recent findings suggest that these tumors may arise instead from hematopoietic progenitor cells. To clarify this ontogenetic dilemma, we used genome-wide expression profiling of primary hemangiosarcomas and identified three distinct tumor subtypes associated with angiogenesis (group 1), inflammation (group 2), and adipogenesis (group 3). Based on these findings, we hypothesized that a common progenitor may differentiate into the three tumor subtypes observed in our gene profiling experiment. To investigate this possibility, we cultured hemangiosarcoma cell lines under normal and sphere-forming culture conditions to enrich for tumor cell progenitors. Cells from sphere-forming cultures displayed a robust self-renewal capacity and exhibited genotypic, phenotypic, and functional properties consistent with each of the three molecular subtypes seen in primary tumors, including expression of endothelial progenitor cell (CD133 and CD34) and endothelial cell (CD105, CD146, and αvß3 integrin) markers, expression of early hematopoietic (CD133, CD117, and CD34) and myeloid (CD115 and CD14) differentiation markers in parallel with increased phagocytic capacity, and acquisition of adipogenic potential. Collectively, these results suggest that canine hemangiosarcomas arise from multipotent progenitors that differentiate into distinct subtypes. Improved understanding of the mechanisms that determine the molecular and phenotypic differentiation of tumor cells in vivo could change paradigms regarding the origin and progression of endothelial sarcomas.

Interleukin-8 promotes canine hemangiosarcoma growth by regulating the tumor microenvironment.

Interleukin-8 (IL-8) gene expression is highly up-regulated in canine hemangiosarcoma (HSA); however, its role in the pathogenesis of this disease is unknown. We investigated the expression of IL-8 in canine HSA tissues and cell lines, as well and the effects of IL-8 on canine HSA in vitro, and in vivo using a mouse xenograft model for the latter. Constitutive expression of IL-8 mRNA, IL-8 protein, and IL-8 receptor were variable among different tumor samples and cell lines, but they showed stable steady states in each cell line. Upon the addition of IL-8, HSA cells showed transient intracellular calcium fluxes, suggesting that their IL-8 receptors are functional and that IL-8 binding activates relevant signaling pathways. Yet, neither addition of exogenous IL-8 nor blockade of endogenous IL-8 by neutralizing anti-IL-8 antibody (α-IL-8 Ab) affected HSA cell proliferation or survival in vitro. To assess potential effects of IL-8 in other tumor constituents, we stratified HSA cell lines and whole tumor samples into "IL-8 high" and "IL-8 low" groups. Genome-wide gene expression profiling showed that samples in the "IL-8 high" tumor group were enriched for genes associated with a "reactive microenvironment," including activation of coagulation, inflammation, and fibrosis networks. Based on these findings, we hypothesized that the effects of IL-8 on these tumors were mostly indirect, regulating interactions with the microenvironment. This hypothesis was supported by in vivo xenograft experiments where survival and engraftment of tumor cells was inhibited by administration of neutralizing α-IL-8 Ab. Together, our results suggest that IL-8 contributes to establishing a permissive microenvironment during the early stages of tumorigenesis in HSA.

A dual-radioisotope hybrid whole-body micro-positron emission tomography/computed tomography system reveals functional heterogeneity and early local and systemic changes following targeted radiation to the murine caudal skeleton.

The purpose of this study was to develop a longitudinal non-invasive functional imaging method using a dual-radioisotope hybrid micro-positron emission tomography/computed tomography (PET/CT) scanner in order to assess both the skeletal metabolic heterogeneity and the effect of localized radiation that models therapeutic cancer treatment on marrow and bone metabolism. Skeletally mature BALB/c female mice were given clinically relevant local radiation (16 Gy) to the hind limbs on day 0. Micro-PET/CT acquisition was performed serially for the same mice on days -5 and +2 with FDG and days -4 and +3 with NaF. Serum levels of pro-inflammatory cytokines were measured. Significant differences (p < 0.0001) in marrow metabolism (measured by FDG) and bone metabolism (measured by NaF) were observed among bones before radiation, which demonstrates functional heterogeneity in the marrow and mineralized bone throughout the skeleton. Radiation significantly (p < 0.0001) decreased FDG uptake but increased NaF uptake (p = 0.0314) in both irradiated and non-irradiated bones at early time points. An increase in IL-6 was observed with a significant abscopal (distant) effect on marrow and bone metabolic function. Radiation significantly decreased circulating IGF-1 (p < 0.01). Non-invasive longitudinal imaging with dual-radioisotope micro-PET/CT is feasible to investigate simultaneous changes in marrow and bone metabolic function at local and distant skeletal sites in response to focused radiation injury. Distinct local and remote changes may be affected by several cytokines activated early after local radiation exposure. This approach has the potential for longer-term studies to clarify the effects of radiation on marrow and bone.

Hepatic insufficiency in two juvenile dogs with histoplasmosis.

A 9-month-old female intact toy poodle and a 1-year-old female intact Labrador retriever mix presented to separate teaching hospitals for chronic histories of malaise and clinicopathologic evidence of hepatic dysfunction. The signalment and clinical histories of these dogs prompted consideration of a congenital portosystemic shunt as a primary differential. However, microscopic evaluation of peritoneal effusion, pleural effusion, and peripheral blood samples from the dogs revealed round to ovoid yeast organisms morphologically most compatible with Histoplasma capsulatum. Additional testing confirmed histoplasmosis in each case. The poodle underwent a computed tomography (CT) study, which showed hepatomegaly with a spleno-gonadal shunt, pancreatic and gastric wall edema, and marked peritoneal effusion, findings compatible with portal hypertension and secondary acquired shunt formation. The dog was later humanely euthanized due to clinical deterioration, and on necropsy hepatic histoplasmosis was verified, with additional affected tissues comprising lungs and spleen. The Labrador Retriever mix responded clinically and clinicopathologically to antifungal therapy, though no abdominal imaging was performed to definitively exclude the possibility of a congenital portosystemic shunt. In retrospect, several features were more compatible with histoplasmosis than portosystemic shunt in these cases, including hyperbilirubinemia, effusion, and hepatomegaly. These findings serve as a reminder of the need to interpret serum biochemical findings in the context of the totality of the clinicopathologic data and imaging findings, as well as the diagnostic value of microscopy in the evaluation of hematologic and body cavity fluid samples.

Telangiectatic osteosarcoma in four dogs: Cytologic, histopathologic, cytochemical, and immunohistochemical findings.

Telangiectatic osteosarcoma is a rare variant of osteosarcoma histologically and clinically similar to hemangiosarcoma (HSA). This case series describes the imaging and cytologic features of four histologically confirmed telangiectatic osteosarcomas, including the use of cytochemical stains. Alkaline phosphatase (ALP) was applied to Wright-Giemsa-stained cytology slides, and Factor VIII immunohistochemistry was evaluated. Cytologic characteristics included atypical mesenchymal cells with evidence of acute and chronic hemorrhage. Telangiectatic osteosarcoma cases had positive ALP cytochemical staining, while control HSA cases were negative. Factor VIII immunohistochemistry was negative in telangiectatic osteosarcoma and positive in HSA. Cytologic diagnosis of telangiectatic osteosarcoma with positive ALP cytochemical staining can help differentiate this neoplasm from HSA.

Differential cardiotoxicity in response to chronic doxorubicin treatment in male spontaneous hypertension-heart failure (SHHF), spontaneously hypertensive (SHR), and Wistar Kyoto (WKY) rats.

Life threatening complications from chemotherapy occur frequently in cancer survivors, however little is known about genetic risk factors. We treated male normotensive rats (WKY) and strains with hypertension (SHR) and hypertension with cardiomyopathy (SHHF) with 8 weekly doses of doxorubicin (DOX) followed by 12weeks of observation to test the hypothesis that genetic cardiovascular disease would worsen delayed cardiotoxicity. Compared with WKY, SHR demonstrated weight loss, decreased systolic blood pressure, increased kidney weights, greater cardiac and renal histopathologic lesions and greater mortality. SHHF showed growth restriction, increased kidney weights and renal histopathology but no effect on systolic blood pressure or mortality. SHHF had less severe cardiac lesions than SHR. We evaluated cardiac soluble epoxide hydrolase (sEH) content and arachidonic acid metabolites after acute DOX exposure as potential mediators of genetic risk. Before DOX, SHHF and SHR had significantly greater cardiac sEH and decreased epoxyeicosatrienoic acid (EET) (4 of 4 isomers in SHHF and 2 of 4 isomers in SHR) than WKY. After DOX, sEH was unchanged in all strains, but SHHF and SHR rats increased EETs to a level similar to WKY. Leukotriene D4 increased after treatment in SHR. Genetic predisposition to heart failure superimposed on genetic hypertension failed to generate greater toxicity compared with hypertension alone. The relative resistance of DOX-treated SHHF males to the cardiotoxic effects of DOX in the delayed phase despite progression of genetic disease was unexpected and a key finding. Strain differences in arachidonic acid metabolism may contribute to variation in response to DOX toxicity.

Accuracy of US-guided FNA of focal liver lesions in dogs: 140 cases (2005-2008).

Medical records from dogs having abdominal ultrasound (US) performed between March 2005 and October 2008 were reviewed for detection of focal liver lesions (FLL) with both cytologic and histologic sampling. Samples were classified as to either the presence or absence of major categories of pathologic processes, including malignant neoplasia, inflammation, hyperplasia/benign neoplasia, vacuolar change, extramedullary hematopoeisis, cholestasis, necrosis, and no microscopic abnormalities. Evaluation of selection bias was performed by review of the relative distribution of cytologic diagnoses for cases with histology compared with cases excluded from the comparison analysis because histology results were not available. Cytology had the highest sensitivity for vacuolar change (57.9%), followed by neoplasia (52.0%). Cytology had the highest positive predictive value (PPV) for neoplasia (86.7%) followed by vacuolar change (51.6%). Cytology had lower sensitivity and PPVs for inflammation, necrosis, and hyperplasia. The ability of cytology to characterize disease in canine FLL varies by pathologic process. Clinicians can have a high degree of confidence when a cytologic diagnosis of neoplasia is given; however, cytology is less reliable for excluding the potential for neoplasia. Cytology has a low sensitivity and PPV for inflammation and a limited diagnostic performance for the diagnosis of vacuolar change.

Premature parturition, edema, and ascites in an alpaca infected with Anaplasma phagocytophilum.

An 8-year-old alpaca was presented for fever, anorexia, edema, ascites, and premature parturition. She was determined to have Anaplasma phagocytophilum infection based on positive blood polymerase chain reaction (PCR) and positive acute and convalescent serum titers. Antibiotics and supportive therapies were administered and the alpaca made a complete recovery.

Parturition prématurée, œdème et ascite chez un alpaga infecté parAnaplasma phagocytophilum. Un alpaga femelle âgé de 8 ans a été présenté pour une fièvre, de l'anorexie, de l'œdème, de l'ascite et une parturition prématurée. On a déterminé qu'elle avait une infection à Anaplasma phagocytophilum en se fondant sur le résultat positif d'un test d'amplification en chaîne par la polymérase (PCR) effectué sur un échantillon sanguin et des titres sériques aigus et convalescents positifs. Des antibiotiques et des thérapies de soutien ont été administrés et l'alpaga s'est rétabli complètement.(Traduit par Isabelle Vallières).

Outcomes assessment of case-based writing exercises in a veterinary clinical pathology course.

Our second-year core clinical pathology course uses free-response case-based learning exercises in an otherwise traditional lecture or laboratory course format to augment the development of skills in application of knowledge and critical thinking and clinical reasoning. We previously reported increased learner confidence accompanied by perceived improvements in understanding and ability to apply information, along with enhanced feelings of preparedness for examinations that students attributed to the case-based exercises. The current study prospectively follows a cohort of students to determine the ability of traditional multiple-choice versus free-response case-based assessments to predict future academic performance and to determine if the perceived value of the case-based exercises persists through the curriculum. Our data show that after holding multiple-choice scores constant, better performance on case-based free-response exercises led to higher GPA and better class rank in the second and third years and better class rank in the fourth year. Students in clinical rotations reported that the case-based approach was superior to traditional lecture or multiple-choice exam format for learning clinical reasoning, retaining factual information, organizing information, communicating medical information clearly to colleagues in clinical situations, and preparing high quality medical records. In summary, this longitudinal study shows that case-based free-response writing assignments are efficacious above and beyond standard measures in determining students' GPAs and class rank and in students' acquisition of knowledge, skills, and clinical reasoning. Students value these assignments and overwhelmingly find them an efficient use of their time, and these opinions are maintained even two years following the course.

Retrospective evaluation of fluid production at the time of thoracostomy tube removal following elective and emergency surgery in dogs (2010-2017): 185 cases.

OBJECTIVE: To report the rate of fluid production at the time of removal of thoracostomy tubes placed intraoperatively and to determine the association of this rate with specific patient factors, surgical factors, or clinical diagnosis. The secondary objective was to determine whether identification of pleural effusion within 2 weeks of thoracostomy tube removal was associated with the same variables. DESIGN: Retrospective study. SETTING: University teaching hospital. ANIMALS: One hundred eighty-five client-owned dogs with thoracostomy tubes placed intraoperatively between January 2010 and March 2017. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thoracostomy tubes were removed at a median fluid production of 0.09 mL/kg/h (range, 0-7.0 m L/kg/h). Median fluid production at the time of thoracostomy tube removal was significantly higher in dogs with preoperative pleural effusion compared to dogs without preoperative pleural effusion (0.21 vs 0.05 mL/kg/h; P = 0.0001) and in dogs that had a median sternotomy compared to dogs that had a lateral thoracotomy (0.14 vs 0.09 mL/kg/h; P = 0.04). Of the 169 dogs available for follow-up, 12 (7.1%) had pleural effusion within 2 weeks of removal of the thoracostomy tube. Detection of pleural effusion during the follow-up period was significantly associated with the presence of preoperative pleural effusion (P = 0.0019) and the diagnosis (P = 0.01). A greater proportion of dogs with a lung lobe torsion (4/9, 44.4%) and idiopathic chylothorax (2/7, 28.5%) had pleural effusion within 2 weeks compared to other diagnoses. Reintervention was performed in 4.7% of dogs. CONCLUSIONS: Thoracostomy tubes were removed at pleural fluid production rates that frequently exceeded current veterinary guidelines. However, the fluid production rate at the time of thoracostomy tube removal was not associated with the detection of pleural effusion within 2 weeks of thoracostomy tube removal, and the overall need for reintervention following thoracostomy tube removal was low (4.7%).

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Advances in the diagnosis of acute pancreatitis in dogs.

In the last 20 years, the diagnosis of pancreatitis has become more frequent as a result of improved diagnostic modalities such as abdominal ultrasound examination, advanced imaging, and immunoassays for the measurement of pancreatic lipase. Our aim is to provide a state-of-the-art overview of the clinical diagnosis of acute pancreatitis (AP) in dogs with a particular focus on pancreatic lipase assay validation and clinical performance, in addition to advanced imaging modalities. We also discuss the potential indications for cytology and histopathology in dogs with suspected AP.

Gene expression profiling identifies inflammation and angiogenesis as distinguishing features of canine hemangiosarcoma.

BACKGROUND: The etiology of hemangiosarcoma remains incompletely understood. Its common occurrence in dogs suggests predisposing factors favor its development in this species. These factors could represent a constellation of heritable characteristics that promote transformation events and/or facilitate the establishment of a microenvironment that is conducive for survival of malignant blood vessel-forming cells. The hypothesis for this study was that characteristic molecular features distinguish hemangiosarcoma from non-malignant endothelial cells, and that such features are informative for the etiology of this disease. METHODS: We first investigated mutations of VHL and Ras family genes that might drive hemangiosarcoma by sequencing tumor DNA and mRNA (cDNA). Protein expression was examined using immunostaining. Next, we evaluated genome-wide gene expression profiling using the Affymetrix Canine 2.0 platform as a global approach to test the hypothesis. Data were evaluated using routine bioinformatics and validation was done using quantitative real time RT-PCR. RESULTS: Each of 10 tumor and four non-tumor samples analyzed had wild type sequences for these genes. At the genome wide level, hemangiosarcoma cells clustered separately from non-malignant endothelial cells based on a robust signature that included genes involved in inflammation, angiogenesis, adhesion, invasion, metabolism, cell cycle, signaling, and patterning. This signature did not simply reflect a cancer-associated angiogenic phenotype, as it also distinguished hemangiosarcoma from non-endothelial, moderately to highly angiogenic bone marrow-derived tumors (lymphoma, leukemia, osteosarcoma). CONCLUSIONS: The data show that inflammation and angiogenesis are important processes in the pathogenesis of vascular tumors, but a definitive ontogeny of the cells that give rise to these tumors remains to be established. The data do not yet distinguish whether functional or ontogenetic plasticity creates this phenotype, although they suggest that cells which give rise to hemangiosarcoma modulate their microenvironment to promote tumor growth and survival. We propose that the frequent occurrence of canine hemangiosarcoma in defined dog breeds, as well as its similarity to homologous tumors in humans, offers unique models to solve the dilemma of stem cell plasticity and whether angiogenic endothelial cells and hematopoietic cells originate from a single cell or from distinct progenitor cells.

Effect of pancreatic tissue sampling on serum pancreatic enzyme levels in clinically healthy dogs.

Little is known about the potential consequences of pancreatic tissue sampling in dogs. The goal of the present study was to evaluate changes in serum trypsin-like immunoreactivity and canine-specific pancreatic lipase after pancreatic fine-needle aspiration and surgical biopsy in 27 clinically healthy dogs. Presurgical, ultrasound-guided aspiration of the pancreas was performed with the dogs under sedation. Subsequently, all the dogs underwent intraoperative pancreatic fine-needle aspiration and clamshell biopsy. After euthanasia, pancreata were sectioned for histopathologic evaluation. Serum pancreatic enzyme levels were measured at 3 time points: baseline, after ultrasound-guided aspiration, and after intraoperative aspiration and biopsy. No significant differences were detected among mean serum pancreatic lipase values at any point (P > 0.05). Serum trypsin-like immunoreactivity did not change from baseline (18.2 +/- 2.1 microg/dl; mean +/- standard error) after ultrasound-guided aspiration (13.6 +/- 2.2 microg/dl) but increased significantly after intraoperative sampling (44.8 +/- 1.9 microg/dl; P < 0.0005). After surgical biopsy, the 20 dogs that had both ultrasound-guided and intraoperative sampling had a higher mean (SE) serum trypsin-like immunoreactivity (44.8 +/- 1.9 microg/dl) than the 7 dogs that had only intraoperative samples taken (36.4 +/- 4.1 microg/dl; P < 0.05). All 27 pancreata were grossly normal before intraoperative sampling. Pancreatic sampling was associated with increased serum trypsin-like immunoreactivity and mild, peracute necrosis, inflammation, hemorrhage, and fibrin deposition. Tissue damage from sampling was not sufficient to cause an elevation in canine-specific pancreatic lipase in the time frame evaluated. Further studies are needed to determine longer-term effects of pancreatic sampling on enzyme levels and clinical outcome.

Nasal rhinosporidiosis in two dogs native to the upper Mississippi river valley region.

Two dogs, 4 and 7 years of age, were presented for evaluation and treatment of excessive sneezing. Physical examinations in both cases were within acceptable limits except for the presence of a single mass in the left nasal passage in the first case and left-sided nasal discharge in the second case. Rhinoscopy was used to visualize the nasal masses, and in both cases a single mass was surgically removed. Impression smears and histopathology submitted from each mass revealed lymphoplasmacytic and neutrophilic inflammation with spores typical of Rhinosporidium seeberi. These are the first reported cases of nasal rhinosporidiosis in two dogs native to the Upper Mississippi River Valley area with no travel history outside the region.

Diagnosis of canine renal lymphoma by cytology and flow cytometry of the urine.

Lymphoma is a common hematopoietic neoplasm of dogs. A definitive diagnosis typically requires the collection of samples via fine-needle aspirate or biopsy. A unique case of canine renal T-cell lymphoma diagnosed using urine sediment microscopy with flow cytometry and PCR for Antigen Receptor Rearrangement (PARR) is presented. A fresh urine sample was collected via a urinary catheter and immediately prepared for cytologic examination, flow cytometry, and PARR. The flow cytometric study revealed that 83% of the cells were large CD3+ CD8+ T cells, while PARR identified a clonally rearranged T-cell receptor gene, supporting the flow cytometry findings. Despite supportive care, the patient progressed to anuric renal failure and was humanely euthanized. A necropsy was performed, and tissues from the upper and lower urinary tracts were collected. Histologically, the right and left kidneys were infiltrated by a neoplastic round cell population effacing the cortex and medulla. Immunohistochemistry for the T- and B-cell antigens CD3 and CD20, respectively, revealed that the neoplastic population within the kidney demonstrated diffuse, strong, membranous to intracytoplasmic CD3 expression while lacking CD20 expression. These results confirmed the diagnosis of renal T-cell lymphoma. This is the first known report of canine lymphoma diagnosed using either urine flow cytometry or clonality testing. Therefore, in select cases, urine flow cytometry and/or PARR are feasible to perform on urine-derived cells as a quick and cost-effective means to aid in the diagnosis of urinary tract lymphoma.