Age, female sex, and 3 genera appeared to be positively associated with the presence of advanced atherosclerotic lesions in psittacine birds. This information may be useful in clinical assessment of the cardiovascular system and patient management. Reproductive diseases were the only potentially modifiable risk factor identified and could be a target for prevention in captive psittacine birds.

Background While hematologic reference intervals (RI) are available for multiple raptorial species of the order Accipitriformes and Falconiformes, there is a lack of valuable hematologic information in Strigiformes that can be used for diagnostic and health monitoring purposes. Objectives The objective was to report RI in Strigiformes for hematologic variables and to assess agreement between manual cell counting techniques. Methods A multi‐center prospective study was designed to assess hematologic RI and blood cell morphology in owl species. Samples were collected from individuals representing 13 Strigiformes species, including Great Horned Owl, Snowy Owl, Eurasian Eagle Owl, Barred Owl, Great Gray Owl, Ural Owl, Northern Saw‐Whet Owls, Northern Hawk Owl, Spectacled Owl, Barn Owl, Eastern Screech Owl, Long‐Eared Owl, and Short‐Eared Owl. Red blood cell count was determined manually using a hemocytometer. White blood cell count was determined using 3 manual counting techniques: (1) phloxine B technique, (2) Natt and Herrick technique, and (3) estimation from the smear. Differential counts and blood cell morphology were determined on smears. Reference intervals were determined and agreement between methods was calculated. Results Important species‐specific differences were observed in blood cell counts and granulocyte morphology. Differences in WBC count between species did not appear to be predictable based on phylogenetic relationships. Overall, most boreal owl species exhibited a lower WBC count than other species. Important disagreements were found between different manual WBC counting techniques. Conclusions Disagreements observed between manual counting techniques suggest that technique‐specific RI should be used in Strigiformes.

The prevalence of atherosclerosis is high in the captive psittacine population and increases with age and female sex. The genera Psittacus, Amazona, and Nymphicus are predisposed to atherosclerosis, whereas the genera Cacatua and Ara are less susceptible. Plasma cholesterol and lipoprotein abnormalities have been suggested as risk factors in the development of atherosclerosis as observed in mammals. To investigate whether the psittacine genera susceptibility to atherosclerosis and the known risk factors of age and sex could be associated with differences in the lipid profile, a retrospective analysis was conducted on blood lipid values from 5625 birds. Prevalence values were obtained from a previously published, large, case-control study and were compared with identified trends in plasma lipid profiles. Genus-specific differences were identified in plasma total cholesterol values that corresponded to observed trends in the prevalence of clinically important atherosclerotic lesions, which were also highly correlated. The effect of age was significant but was mild and may not account for the dramatic increase in atherosclerosis prevalence observed with age. In addition, Quaker parrots ( Myiopsitta monachus ), which were used as experimental models for psittacine atherosclerosis and dyslipidemia, were found to have the highest values in all lipid profile parameters. The results of this study suggest that the differences observed in prevalence among species of the psittacine genera may partly be explained by differences in plasma total cholesterol levels. Results also support the use of Quaker parrots as models for studying atherosclerosis and dyslipidemia.

Lymphoma is a common tumor in ferrets, but anatomic distribution, histomorphology, immunophenotype, laboratory abnormalities, and response to chemotherapy are incompletely defined. In this study, lymphoma was diagnosed by histopathology of tumor tissue in 29 ferrets ranging in age from 0.8 to 8.5 years, including 12 males and 17 females. Tumors involved the viscera of the abdominal cavity (n = 11), thoracic cavity (n = 1), or abdominal and thoracic cavities (n = 7); the skin (n = 2); or the viscera of both body cavities plus other sites (n = 8). Microscopically, all tumors had diffuse architecture. Assessment by histomorphology and immunophenotype classified tumors as peripheral T-cell lymphoma (n = 17), anaplastic large T-cell lymphoma (n = 5), anaplastic large B-cell lymphoma (n = 4), diffuse large B-cell lymphoma (n = 1), and Hodgkin-like lymphoma (n = 2). Cytologic evaluation of tumor tissue was diagnostic in 11 of 13 cases. Twenty-two of 27 ferrets had anemia, 2 had leukemia, and 5 were neutropenic. Common comorbid disorders were adrenal disease (n = 27) and insulinoma (n = 6). Tumors most frequently involved mesenteric lymph nodes, while enlargement of peripheral lymph nodes was uncommon (n = 3). Ferrets with Hodgkin-like lymphoma had massive enlargement of single lymph nodes. Mean survival of ferrets not immediately euthanized was 5.0 months (T-cell lymphoma) and 8.4 months (B-cell lymphoma). Ferrets treated with chemotherapy survived an average of 4.3 months (T-cell lymphoma, n = 9) or 8.8 months (B-cell lymphoma, n = 4). Results indicate that lymphomas in ferrets most commonly affect abdominal viscera, may be amenable to cytologic diagnosis, are frequently associated with anemia and, in some cases, may be chemosensitive, resulting in relatively long survival times.

Overall, this study suggests that the Vetscan has acceptable clinical performance in Strigiformes for some analytes and highlights discrepancies for several analytes.

Background: Lipid accumulation disorders, such as atherosclerosis and hepatic lipidosis, are common in psittacine birds and associated with various dyslipidemias. Gel-permeation high-performance liquid chromatography (GP-HPLC) is a reference method for advanced lipoprotein profiling based on particle size separation, followed by an analysis of lipid contents. Objectives: The objectives were to (a) characterize Quaker parrot lipoproteins using a commercial GP-HPLC method (Liposearch panel), and (b) obtain preliminary information on the reliability of the Friedewald formula for low-density lipoprotein-cholesterol (LDL-C) measurements. Methods: Plasma samples were collected from 12 fasted healthy Quaker parrots. Cholesterol concentrations, triglyceride concentrations, particle sizes, and particle numbers were determined by GP-HPLC for four classes and 20 sub-fractions of lipoproteins. The LDL-C concentrations obtained using the Friedewald formula and direct measurements were compared with Bland-Altman plots. Alternate formulas were determined using multiple linear regression. Results: High-density lipoprotein (HDL) was the predominant lipoprotein in Quaker parrots, and most particles were of medium-to-small sizes belonging to two subfractions (average size, 10.6 nm). LDL was the second most common lipoprotein and included large-to-small particles belonging to three sub-fractions (average size, 24.9 nm). Very-low-density lipoproteins (VLDL) and portomicrons were present in low concentrations. The Friedewald formula underestimated LDL-C concentrations with a significant bias of 0.44 mmol/L. An alternate formula was proposed: LDL-C = 0.75*Non-HDL-C. Conclusions: GP-HPLC allowed unprecedented characterization of plasma lipoproteins in Quaker parrots. Characterizing psittacine lipoprotein is useful for validation and interpretation of routine clinical tests as well as for use in epidemiologic and experimental research on psittacine lipid accumulation disorders. K E Y W O R D S cholesterol, Friedewald formula, HDL, LDL, lipoprotein particle number, triglycerides How to cite this article: Beaufrère H, Gardhouse S, Ammersbach M. Lipoprotein characterization in Quaker parrots (Myiopsitta monachus) using gel-permeation highperformance liquid chromatography.

Background: Glucocorticoids are commonly administered to dogs for the treatment of inflammatory disorders, autoimmunity and cancers such as lymphoma. Despite evidence of clinical efficacy, understanding of the effects of glucocorticoids on cells of the canine immune system is limited.Hypothesis: Glucocorticoids affect the expression of phenotypic markers on canine lymphocytes and induce apoptosis. Animals: Fifteen healthy mixed breed dogs. Methods: Prospective randomized study. Prednisone was administered orally for 3 days, and cells aspirated from the popliteal lymph node before prednisone administration, and on days 1, 3, 10, 17, 24, and 38, were labeled with antibodies against canine CD3, CD4, CD8a, CD18, CD21, CD45, CD45RA, and CD90 molecules, and analyzed by flow cytometry. Additional samples were cultured in media with prednisolone for 24 hours and analyzed by cytometry for marker expression, and by gel electrophoresis for DNA fragmentation.Results: Treatment of dogs with glucocorticoids resulted in reduced (p # .05) proportions of CD3 (days 1, 3, 17, and 24), CD4 (days 3 and 10), CD21 (day 1, 3, and 38), CD45RA (day 17) and CD90 (days 1, 10, and 17) expressing lymphocytes, and reduced intensity of CD18 (day 17) and CD45 (day 17 and 24) molecules on nodal lymphocytes. Culture of lymphocytes with prednisolone for 24 hours caused a significant reduction in the expression of all markers (p # .05) and DNA fragmentation.Conclusions and Clinical Importance: Glucocorticoids significantly alter the expression of phenotypic markers on canine lymphocytes, and in vitro induce apoptosis. These findings identify potential mechanisms for clinical immunosuppression from glucocorticoid treatment.

The avian hemogram is usually performed in veterinary diagnostic laboratories by using manual cell counting techniques and differential counts determined by light microscopy. There is no standard automated technique for avian blood cell count and differentiation to date. These shortcomings in birds are primarily because erythrocytes and thrombocytes are nucleated, which precludes the use of automated analyzers programmed to perform mammal complete blood cell counts. In addition, there is no standard avian antibody panel, which would allow cell differentiation by immunophenotyping across all commonly seen bird species. We report an alternative hematologic approach for quantification and differentiation of avian blood cells by using high-throughput image cytometry on blood smears in psittacine bird species. A pilot study was designed with 70 blood smears of different psittacine bird species stained with a Wright-Giemsa stain. The slides were scanned at 0.23 microm/pixel. The open-source softwares CellProfiler and CellProfiler Analyst were used for analyzing and sorting each cell by image cytometry. A "pipeline" was constructed in the CellProfiler by using different modules to identify and export hundreds of measures per cell for shape, intensity, and texture. Rules for classifying the different blood cell phenotypes were then determined based on these measurements by iterative feedback and machine learning by using CellProfiler Analyst. Although this approach shows promises, avian Leukopet results could not be duplicated when using this technique as is. Further studies and more standardized prospective investigations may be needed to refine the "pipeline" strategy and the machine learning algorithm.