Estimating leukocyte,platelet, and erythrocyte counts in rats by blood smear examination

Background: The CBC is an essential test for assessing the health of rats used in drug development studies. Because of limited blood volume, estimates of cell counts from a blood smear would be valuable when other analytical methods of enumerating cells are not possible or available. Objective: The purpose of this study was to develop a statistical model to accurately estimate WBC, platelet (PLT), and RBC counts in blood smears from rats. Method: Blood smears and quantitative cell counts were obtained from vehicle‐treated male and female Fischer 344 rats (n=65) involved in a variety of studies. The numbers of WBCs, PLTs, and RBCs were estimated in 10 fields in the monolayer of smears using × 20 (WBC) or × 100 (PLT, RBC) objectives. Using a statistical model and the quantitative cell counts obtained on an ADVIA 120 hematology analyzer, formulas were developed to predict the quantitative counts from the estimates. Results: Data were log‐transformed before analysis. A formula was derived using the slope and intercept of the regression line between cell estimates and ADVIA counts to predict WBC, PLT, and RBC counts based only on estimates. A second formula was developed for situations in which limited quantitative analyses may be available, and resulted in even more accurately predicted counts from smear estimates. Conclusion: The formulas developed in this study can be a valuable tool in estimating cell counts from a blood smear when cell counting instruments are not available or when an instrument cell count needs to be verified. These formulas may be useful in the assessment of rat blood in discovery and lead optimization studies.     

Hematology of the sandbar shark, Carcharhinus plumbeus: standardization of complete blood count techniques for elasmobranchs

BACKGROUND: Standardized hematologic methods and reference intervals have not been established for cartilaginous fishes (sharks, skates, and rays) despite the large number of animals displayed in zoos and aquariums worldwide. OBJECTIVE: The focus of this study was to validate CBC methods for sandbar shark (Carcharhinus plumbeus) blood, based on criteria established in human medicine, for the following tests: RBC count, total WBC count, PCV, hemoglobin (Hgb) concentration, and WBC differential percentages. METHODS: Replicate CBCs were performed using blood samples from 5 captive sandbar sharks. Three protocols for RBC and total WBC counts were compared, as were different centrifugation times for PCV determination, and 2 methods for Hgb concentration. Means, minimum and maximum values, and CVs were compared to CAP and CLIA performance guidelines for human tests. RESULTS: Total WBC counts in a diluent modified for elasmobranch blood, Hgb concentration by the cyanmethemoglobin method after removal of nuclei, and WBC differential percentages showed acceptable performance. PCV results were acceptable when tubes were centrifuged for at least 5 minutes. Total RBC counts by all 3 methods exceeded the acceptable error for manual counts of human cells. CONCLUSIONS: Standardized CBC tests can be used as health assessment tools for elasmobranchs. Total RBC counts should be viewed as estimates.     

Evaluation of equine hemograms using the ADVIA 120 as compared with an impedance counter and manual differential count

BACKGROUND: The ADVIA 120 is an automated laser cell counter widely used in veterinary medicine. Although specific software for equine samples is available and validated, only a few reports have been published comparing the ADVIA 120 with other methods for equine hemogram evaluation. OBJECTIVES: The purpose of this study was to compare the hematologic values and reference intervals obtained on the ADVIA 120 with those obtained on an impedance cell counter and manual differential counts in healthy horses. METHODS: EDTA-anticoagulated blood samples were obtained from 114 clinically healthy horses of various breeds, both sexes, and 2-6 years of age. Samples were stored for up to 12 hours at 4 degrees C and then analyzed on the ADVIA 120 and the Hemat 8. A 100-cell to 200-cell differential leukocyte count was performed by 3 independent observers on May-Grünwald-Giemsa-stained smears. Intra-assay precision of the ADVIA 120 was determined by analyzing 5 replicates each of 10 of the blood samples. RESULTS: Results from the ADVIA were significantly higher than those from the impedance counter for RBC count, total WBC count, hemoglobin concentration, red cell distribution width, MCH, and MCHC, and significantly lower for HCT and platelet count. Significantly higher neutrophil and basophil counts and significantly lower lymphocyte counts were obtained with the ADVIA 120 compared with manual counts. Based on Passing-Bablok regression analysis, RBC and platelet counts were in good agreement between the 2 analyzers; a constant and proportional bias was present for other values. Coefficients of variation for erythrocyte parameters on the ADVIA were <1%, but were higher for platelet (6%), total WBC (2%), differential WBC (4%-30%), and reticulocyte (75%) counts. CONCLUSIONS: Results obtained with equine samples on the ADVIA 120 were comparable with those obtained on an impedance counter; reference intervals differed statistically but overlapped. The ADVIA had poor precision for reticulocyte and differential leukocyte counts such that the latter should always be verified on smears.     

Characterization and quantification of blood cells from the umbilical cord of dogs

BACKGROUND: Models for the study of hematopoietic stem cells in dogs provide important information for bone marrow transplantation in humans. Recent studies have reported the importance of human umbilical cord blood (UCB) as an alternative to allogenic bone marrow for hematopoietic reconstitution. However, there are no studies on the UCB cells of dogs. OBJECTIVE: The aim of this experiment was to characterize and quantify the blood cells of the umbilical cord of dogs. METHODS: The blood of the umbilical cord of 20 neonatal dogs, delivered at term, with a median gestation time of 58 days, was collected with a 5-mL syringe containing EDTA. Total RBC, WBC, and platelet counts, HCT, hemoglobin (Hgb) concentration, and RBC indices were determined using an automatic cell counter. The differential leukocyte count was determined manually in blood smears stained with May-Grünwald-Giemsa. Reticulocyte percentages were determined on blood smears stained with brilliant cresyl blue and counterstained with May-Grünwald Giemsa. RESULTS: The MCHC and numbers of RBCs, WBCs, neutrophils, and eosinophils in UCB were lower as compared with reference values for the peripheral blood of healthy neonatal and adult dogs; whereas, the MCV and reticulocyte percentages were higher. CONCLUSION: Erythrocyte macrocytosis and hypochromasia in UCB were consistent with marked reticulocytosis and indicative of high erythropoietic activity. The results of this study are an important first step in the characterization of UCB from neonatal dogs.     

Interpretation of canine and feline blood smears by emergency room personnel

Background: Interpretation of blood smears is commonly used to provide rapid laboratory evaluation of animals in veterinary emergency practice, but the accuracy of results of blood smear interpretation by emergency room personnel (ERP) compared with evaluation by trained veterinary clinical pathology personnel is unknown. Objective: The goal of this study was to compare blood smear evaluation by ERP with that of clinical pathology personnel. Methods: All animals that had a CBC determined by a diagnostic laboratory and had blood smears evaluated by personnel at the Foster Hospital for Small Animals Emergency Room between September 2008 and July 2009 were eligible for study inclusion. ERP who evaluated blood smears completed standardized forms with estimates of the WBC and platelet counts and evaluation of RBC and WBC morphology. Results from point‐of‐care assessment were compared with automated or manual results reported by the veterinary diagnostic laboratory. Results: One hundred and fifty‐five blood smears were evaluated. There was moderate agreement (κ value, 0.63; 95% confidence interval [CI]: 0.52, 0.74) between estimated platelet counts by ERP and automated counts. Poor agreement was found between estimated WBC counts by ERP and automated counts (κ value, 0.48; 95% CI: 0.37, 0.60). Specific abnormalities with a high likelihood of clinical significance, eg, toxic change, nucleated RBCs, spherocytes, hemoparasites, and lymphoblasts, were not predictably identified by ERP. Conclusions: ERP interpretation of canine and feline blood smears should be used cautiously and should not replace evaluation by a veterinary diagnostic laboratory.     

Analysis of canine and feline haemograms using the VetScan HMT analyser

The VetScan HMT is an impedance counter haematology analyser which produces a full blood count and three-part white blood cell differential. The aim of this study was to compare the results generated by the analyser with those obtained by standard methods used routinely in the authors' laboratory. Blood samples from 68 dogs and 59 cats were run on the VetScan HMT analyser and also subjected to reference methods, and the results obtained were compared. Correlation coefficients (feline/canine) were: 0.97/0.99 for haematocrit (Hct), 0.98/0.99 for haemoglobin (Hb), 0.81/0.98 for total white blood cells (WBC), and 0.89/0.97 for granulocyte and 0.65/0.93 for platelet counts. Coefficients for lymphocyte counts were 0.25/0.28 and for monocyte counts were 0.12/0.79. In conclusion, the VetScan HMT performed well on canine samples, showing excellent correlation for canine Hct, Hb, RBC, WBC, granulocyte and platelet counts. For feline samples, although there was excellent correlation for Hct, Hb and RBC, the WBC and three-part white blood cell differential and platelet count should be interpreted with caution as they can be unreliable.     

Hematology analyzer comparison: Ortho ELT-8/ds vs. Baker 9000 for healthy dogs,mice,and rats

A Baker 9000 hematology analyzer (electronic impedance) was purchased to replace an Ortho ELT-8/ds analyzer (laser optics) due to discontinued technical support. An analytical comparison of hemograms from healthy dogs, rats, and mice was made from paired disodium ethylenediamine tetra-acetate anticoagulated blood samples. Both instruments were calibrated with human blood products, and the ELT-8/ds hematocrit (HCT) was calibrated to a spun packed cell volume (PCV) for each species. For Beagle dogs (n = 49), Baker 9000 mean platelet (PCV) counts had a negative bias of -89 X 10(3)/microliter when compared to ELT-8/ds values. Mean +/- standard error manual PLT counts compared well with Baker 9OOO values for dogs (n = 10): 369 +/- 28 vs. 367 +/- 27 X 10(3)/microliter; r = 0.93. For CD-1 mice (n = 44), Baker 9000 mean white blood cell (WBC) counts had positive biases of 1. 1 X 10(3)/microliter when compared to ELT-8/ds and 0.5 X 10(3)/microliter when compared to hemacytometer counts. Diluted microsamples using the predilution mode on the Baker 9000 compared well with undiluted samples for mice. For Sprague-Dawley rats (n = 70), Baker 9000 mean WBC, red blood cell (RBC), and PLT counts had absolute biases of 0.8 X 10(3)/microliter, -1.09 X 10(6)/microliter, and -357 X 10(3)/microliter, respectively, when compared to ELT-8/ds values. Baker 9000 RBC, WBC, and PLT counts from rats compared well with reference hemacytometer counts. The Baker 9000 HCT determination for rats had an absolute negative bias of 6% when compared to the ELT-8/ds values or spun PCV. The Baker 9000 required whole blood calibration to PCV for accurate determination of HCT for rats. The biases between analyzers may be due to inherent physical differences between the analytical methods and/or the calibration techniques.     

Clinical evaluation of the CA530-VET hematology analyzer for use in veterinary practice

BACKGROUND: The CA530-VET is a completely automated impedance cell hematology analyzer, which yields a 16-parameter blood count including a 3-part leukocyte differential. OBJECTIVES: The aim of this study was to examine the operational potential of the CA530-VET and its value for use in veterinary practice. METHODS: The analyzer was tested for blood carry-over, precision, and accuracy. Comparison methods included the CELL-DYN 3500, microhematocrit centrifugation, manual platelet (PLT) counting for feline and equine species, and a 100-cell manual WBC differential. Blood samples for comparison of the methods were obtained from 242 dogs, 166 cats, and 144 horses. RESULTS: The carry-over ratio (K) was 0.28% for RBC, 0.59% for PLT, 0.32% for WBC, and 0.18% for hemoglobin (HGB) concentration. Coefficients of variation (CVs) for within-batch precision and duplicate measurement of blood samples were clearly within the required limits, except for duplicate platelet counts in cats (8.7%) and horses (9.5%). The WBC count was in excellent agreement for dogs and horses and RBC count was in excellent agreement for horses. The accuracy of feline WBC counts was not acceptable, with the exception of values at the high end of the range. RBC counts in dogs and cats, and HGB concentration and MCV in all 3 species were sufficiently accurate. The CA530-VET HCT results were in excellent agreement with microhematocrit results in horses but exceeded the maximum allowed inaccuracy for cats and dogs. In all species, PLT counts established mechanically and manually were not in adequate agreement. Large differences were found between the CA530-VET and the manual differential percentage for lymphocytes and "mid-sized cells" (monocytes and basophilic granulocytes). CONCLUSIONS: The CA530-VET can be considered useful for routine canine, feline, and equine blood cell analyses. It should not be considered accurate, however, for PLT counts, feline total WBC counts in the subnormal and normal range, and leukocyte differentials, except for granulocytes.     

Hematologic reference intervals for koi (Cyprinus carpio), including blood cell morphology, cytochemistry, and ultrastructure

BACKGROUND: Hematologic data are used routinely in the health care of humans and domestic mammals. Similar data for fish are largely fragmentary or have not been collected. OBJECTIVES: The primary purpose of this study was to determine hematologic reference intervals for koi, an ornamental strain of the common carp (Cyprinus carpio). Secondarily, the morphology, cytochemical reactions, and ultrastructure of koi blood cells were characterized. METHODS: A CBC was performed manually on heparin-anticoagulated blood specimens using Natt and Herrick's diluent and a Neubauer-ruled hemacytometer. Leukocyte differential counts were done on Wright-Leishman- and Diff-Quik-stained blood smears. Cytochemical reactions of koi leukocytes were determined using commercial kits. Transmission electron microscopy was performed to characterize the ultrastructural features of koi blood cells. RESULTS: Hematologic reference intervals were established for healthy koi for PCV (30-34%), hemoglobin concentration (6.3-7.6 g/dL), RBC count (1.7-1.9 X 10(6)/ microL), WBC count (19.8-28.1 X 10(3)/ microL), RBC indices, and differential leukocyte counts. Lymphocytes were the predominant leukocyte (accounting for up to 80% of all leukocytes), whereas eosinophils were rare. Basophils were positive with PAS staining. Naphthol AS-D chloroacetate esterase activity was observed only in eosinophils. alpha-Naphthyl butyrate esterase and beta-glucuronidase activities were positive in monocytes. Some lymphocytes were reactive for alpha-naphthyl butyrate esterase and acid phosphatase activity. Ultrastructurally, leukocytes, erythrocytes, and thrombocytes were identified on the basis of cytoplasmic organelles and granule appearance. CONCLUSION: Hematologic reference intervals and knowledge of the cytochemical reactions and ultrastructural characteristics of koi leukocytes will help standardize hematologic studies in this species.     

Leukocyte and thrombocyte reference values for channel catfish (Ictalurus punctatus Raf), with an assessment of morphologic, cytochemical, and ultrastructural features

BACKGROUND: Hematology tests are useful to evaluate physiologic disturbances in fish and can provide important information for the diagnosis and prognosis of disease. OBJECTIVES: The primary purpose of this study was to define reference intervals for thrombocytes and leukocytes in healthy channel catfish (Ictalurus punctatus). In addition, the morphologic, cytochemical, and ultrastructural features of blood cells were assessed. METHODS: Blood samples (0.5 mL) were collected into EDTA from 40 clinically healthy catfish on a commercial fish farm in Jaboticabal, Brazil. Thrombocyte, total WBC, and differential WBC counts were determined and reference intervals were calculated as the 25-95th percentiles of data. Thrombocyte and leukocyte morphology was assessed in blood smears stained with May Grünwald-Giemsa-Wright and ultrastructurally by transmission electron microscopy. Cytochemical staining patterns were described using periodic acid-Schiff (PAS), peroxidase, nonspecific esterase, alkaline phosphatase, and toluidine blue. RESULTS: Reference intervals were as follows: thrombocytes 58,802-99,569/microL; total WBCs 27,460-41,523/microL; lymphocytes 5380-11,581/microL; monocytes 2949-7459/microL; neutrophils 12,529-22,748/microL, and basophils 736-2003/microL. Neutrophils were positive for peroxidase and PAS; monocytes were positive for nonspecific esterase; and basophils were positive with toluidine blue. CONCLUSION: The morphologic and staining features of neutrophils and monocytes of channel catfish are similar to those of mammals, and the presence of basophils in this species was verified. These reference intervals and morphologic findings provide a foundation for future investigations on the functions and alterations of blood cells in channel catfish.     

Evaluation of peritoneal fluid following intestinal resection and anastomosis in horses.

Postoperative abdominal fluid changes were compared in 2 groups of horses; those undergoing double small-colon resection and anastomosis (n = 10) and those undergoing exploratory celiotomy alone (n = 5). Peritoneal fluid was collected before surgery and on postoperative days 1, 3, 5, and 7. Total and differential nucleated cell counts, RBC numbers, and total protein and fibrinogen concentrations were evaluated. In both groups, all values were significantly higher than normal on the first postoperative day (after small-colon resection and anastomoses, WBC = 130,350 +/- 23,310 cells/microliters, RBC = 7,389,000 +/- 6,234,000 cells/microliters, total protein = 3.63 +/- 0.16 g/dl; after exploratory celiotomy alone, WBC = 166,620 +/- 34,340 cells/microliters, RBC = 295,000 +/- 86,070 cells/microliters, total protein 4.38 +/- 0.54 g/dl). The number of total peritoneal nucleated cells and RBC significantly decreased after the first postoperative day, whereas total protein and fibrinogen concentrations, percent neutrophils, and percent mononuclear cells remained unchanged. None of the values had returned to normal by postoperative day 7 (after small-colon resection and anastomoses, WBC = 45,600 +/- 8,765 cells/microliters, RBC = 95,390 +/- 53,380 cells/microliters, total protein = 4.39 +/- 0.23 g/dl; after exploratory celiotomy alone, WBC = 43,340 +/- 7,746 cells/microliters, RBC = 12,860 +/- 11,790 cells/microliters, total protein = 3.92 +/- 2.20 g/dl.) The resection and anastomosis group had a significantly lower total protein concentration on the first postoperative day and a significantly higher mean total RBC count over the entire 7-day postoperative evaluation than did horses that underwent celiotomy alone. Other values in the 2 groups of horses did not differ significantly.(ABSTRACT TRUNCATED AT 250 WORDS)     

Concurrent infection with bovine leukaemia virus and <Emphasis Type="Italic">Theileria annulata</Emphasis> in a Friesian calf

Concurrent infection with bovine leukaemia virus (BLV) and Theileria annulata was diagnosed in a Friesian calf about 6 months of age at a dairy farm at the Qassim region of central Saudi Arabia. The disease ended fatally with signs of liver and heart failure. There was anorexia, pyrexia, anaemia, generalized oedema and jaundice. Haematology showed low RBC counts, PCV percentage and haemoglobin concentration and WBC counts. Lymphocyte differential was high. Examination of blood smears stained with Giemsa’s stain showed the presence of piroplasms in red blood cells. Autopsy showed enlarged lymph nodes and lymphosarcoma lesions in the omentum and the heart. There was hydroperitoneum, hydropericardium and hydrothorax. The liver was pale yellow and friable. Impression smears from sliced lymph nodes and stained with Giemsa’s stain showed presence of Koch’s blue bodies in lymphoblasts. Histopathological examination revealed fatty degeneration of hepatocytes and pleomorphic lymphoblasts and giant cells in lymph nodes. Lymphoblasts infiltrated the omentum and heart tissues. Amyloid was found around blood vessels in the liver, kidneys and lymph nodes. BVL infection was diagnosed by demonstrating antibodies against the virus in serum using agar gel immunodiffusion and was confirmed with ELISA.     

Single-step technique for staining Anaplasma marginale in bovine blood smears.

Three available differential stains, Camco-Quik, Diff-Quik, and Wright-Giesma were compared for detection of intraerythrocytic Anaplasma marginale in bovine blood smears. In samples where < 1% to more than 51% of the RBC were infected, statistical analysis of the data indicated no significant difference in the detection of A marginale with Camco-Quik or Diff-Quik stains. However, a significantly lower percentage of infected RBC were detected when blood smears were stained with the Wright-Giemsa stain, compared with the other 2 methods.     

Age-related changes in selected haematology parameters in rabbits

Even though there is an abundance of information on the reference values of haematological parameters in adult rabbits, a little is known about the changes in haematology in newborn rabbits or during their postnatal development. Therefore, the aim of our study was to investigate changes in red blood cells (RBC), white blood cells (WBC) and differential leukocyte counts in SPF New Zealand White rabbits from the age of one day to 20 weeks. Significant age-related changes during the first four weeks of life were detected. These included an increase of RBC and WBC, reversal of the neutrophil/lymphocyte ratio and increase of total counts of eosinophils and basophils. From the age of six weeks of life, all of the studied haematological parameters were comparable to those of adult rabbits.     

Evaluation of the ADVIA 120 for analysis of canine cerebrospinal fluid

BACKGROUND: Conventional techniques for canine cerebrospinal fluid (CSF) analysis require large sample volumes and are labor intensive and subject to operator variability. Objective: The purpose of this study was to evaluate the ADVIA120 CSF assay for analysis of canine CSF samples. METHODS: CSF samples collected from 36 healthy control dogs and 17 dogs with neurologic disease were processed in parallel using the automated assay and established manual methods using a hemocytometer and cytocentrifugation. Results for WBC (total nucleated cell) count, RBC count, and differential nucleated cell percentages were compared using Spearman rank correlation coefficients and Bland-Altman bias plots. RESULTS: Correlation coefficients for WBC and RBC counts were 0.57 and 0.83 for controls, and 0.92 and 0.94 for ill dogs, respectively. Coefficients for the percentages of neutrophils, lymphocytes, and monocytes were 0.53, 0.26, and 0.12 for controls and 0.77, 0.92, and 0.70 for dogs with neurologic disease. When data were combined (n=53), correlation coefficients were 0.86 and 0.91 for WBC and RBC counts, and 0.63, 0.43, and 0.30 for neutrophil, lymphocyte, and monocyte percentages. A 9.5% positive bias and 7.0% negative bias were obtained for the ADVIA 120 CSF assay for lymphocytes and macrophages in dogs with neurologic disease with Bland-Altman analysis. A 12.2% positive bias was found for lymphocyte percentage in dogs with neurologic disease. CONCLUSIONS: Manual and automated CSF assays had moderate to excellent correlation for WBC and RBC concentrations, but results were more variable for differential cell percentages. The ADVIA assay may be more useful for assessment of canine CSF with adjustment of cell differentiation algorithms.     

Comparative study of hematologic and plasma biochemical variables in Eastern Atlantic juvenile and adult nesting loggerhead sea turtles (Caretta caretta)

Background: Plasma biochemical and hematologic variables are important in the management of endangered sea turtles, such as loggerheads. However, studies on blood biochemistry and hematology of loggerheads are limited, and different concentrations according to variable criteria have been reported. Objective: The purpose of this study was to establish and compare baseline plasma chemistry and hematology values in Eastern Atlantic juvenile and adult nesting loggerhead sea turtles (Caretta caretta). Methods: Blood samples were collected from 69 healthy juvenile loggerhead sea turtles after their rehabilitation in captivity, and from 34 adult nesting loggerheads after oviposition. Fresh blood was used for leukocyte differential count and PCV determination. Heparinized blood was used for RBC and WBC counts. Plasma biochemical concentrations were measured using an automated biochemical analyzer. For the comparative study, nonparametric statistical analysis was done using the Mann–Whitney U‐test. Results: Minimum, maximum, and median concentrations were obtained for 14 hematologic and 15 plasma chemistry variables. Statistically significant differences between juvenile and adult turtles were found for PCV; RBC, WBC, and leukocyte differential counts; total protein, albumin, globulins, calcium, triglycerides, glucose, total cholesterol and urea concentrations; and lactate dehydrogenase activity. Conclusions: Age, size, and reproductive status cause important variations in the hematologic and plasma biochemical results of loggerheads. The reference values obtained in this study may be used as a standard profile, useful for veterinary surgeons involved in sea turtle conservation.     

Red cell morphologic alterations in cats with hepatic disease

Medical records from 39 cats with hepatic disease, examined at the Veterinary Medical Teaching Hospital, University of Florida, between 1987 and 1992 were retrospectively evaluated for alterations in red blood cell (RBC) morphology. Diagnoses included: hepatic lipidosis, neoplasia, cholangiohepatitis, hepatitis/hepatopathy, systemic histoplasmosis, and portocaval shunt. A total of 56 laboratory data sets were studied which included complete blood counts and serum chemistry results. Stained blood smears were evaluated from 51 of the data sets. Twenty-two cats (56%) were determined to have poikilocytosis on the basis of blood smear evaluation. Eleven (28%) cats had moderate to marked poikilocytosis (2+ to 4+). Acanthocytes accounted for 62.6 -/+ 22.1% of morphologically abnormal RBC and were observed in blood smears from 100% of cats with poikilocytosis. Elliptocytes (ovalocytes) comprised 19.5 -/+ 15.8% of poikilocytes and were found in smears from 82% of cats with poikilocytosis. Keratocytes (7.0 -/+ 6.8%), schistocytes (3.6 -/+ 4.4%), and blister cells (2.6 -/+ 6.4%) were present in lower numbers and in fewer cats. Serum total cholesterol values were significantly greater (p < 0.05) in cats with moderate to marked alterations in RBC morphology. Cats with hepatic lipidosis were significantly (p < 0.04) more likely to have poikilocytosis than cats with other types of hepatic disease.     

Spurious,marked leukocytosis in 2 cats with Heinz body hemolytic anemia

Two domestic shorthair cats were presented with anorexia and dehydration following ingestion of caramelized onions. Shared key findings from a CBC (ADVIA 2120), serum biochemistry, and urinalysis included a spurious, marked leukocytosis with discordant basophil (BASO) channel and peroxidase channel WBC counts, normal manual leukocyte counts, mild, non-regenerative anemia with discrepancies between automated and manual reticulocyte counts, an abundance of large Heinz bodies (HBs), and highly irregular scattergrams. Case 1 also demonstrated a markedly elevated mean corpuscular hemoglobin concentration (MCHC) and discrepancies between RBC hemoglobin indices. Spurious leukocyte results were confirmed through re-analysis of samples (including the acquisition of a new sample, use of an alternate analyzer (Sysmex XT-2000iV; Case 1 only), and evaluation of scattergrams and blood films (Cases 1 and 2). Repeatedly discrepant reticulocyte counts were also identified. In both cases, the erroneous BASO WBC counts, discrepancies in reticulocyte counts and RBC indices, and atypical scattergrams were interpreted to result from various effects of the HBs. These cases emphasize the importance of reviewing blood films, interpreting scattergrams, and the usefulness of duplicate methods for determining various measurands on hematology analyzers.     

Hematologic evaluation of normal and anemic lambs with the Technicon H*1 using EDTA or heparin as anticoagulants

Abstract: A study was performed to evaluate blood from young lambs using the Technicon H*1 hematology analyzer, with emphasis on RBC parameters, comparison of tripotassium EDTA and heparin, and the effects of storage on heparinized blood. Blood samples from lambs 2 days to 18 weeks of age were analyzed within 6 hours, revealing a high precision, except for WBC counts in heparinized blood. The HCT values estimated by the H*1 correlated well (r²= .90) with those obtained by the microhematocrit method. Mean hematologic values obtained for heparinized blood differed by up to 4% from values obtained for blood collected into EDTA. WBC counts decreased 8.4% in heparinized blood stored at 4°C for 1 day, but differences observed in RBC counts were ≤ 2%. Problems occurred when analyzing blood from young lambs with low hemoglobin values because the H*1 incorrectly counted microcytes with volumes of < 10 fL as platelets. When the necessary corrections were performed, the H*1 was useful for analyzing RBC parameters in lamb blood collected both into EDTA and into heparin.     

Comparison of white blood cell differential percentages determined by the in-house LaserCyte hematology analyzer and a manual method

BACKGROUND: The LaserCyte hematology analyzer (IDEXX Laboratories, Chalfont St. Peter, Bucks, UK) is the first in-house laser-based single channel flow cytometer designed specifically for veterinary practice. The instrument provides a full hematologic analysis including a 5-part WBC differential (LC-diff%). We are unaware of published studies comparing LC-diff% results to those determined by other methods used in practice. OBJECTIVE: To compare LC-diff% results to those obtained by a manual differential cell count (M-diff%). METHODS: Eighty-six venous blood samples from 44 dogs and 42 cats were collected into EDTA tubes at the Forest Veterinary Centre (Epping, UK). Samples were analyzed using the LaserCyte within 1 hour of collection. Unstained blood smears were then posted to Langford Veterinary Diagnostics, University of Bristol, and stained with modified Wright's stain. One hundred-cell manual differential counts were performed by 2 technicians and the mean percentage was calculated for each cell type. Data (LC-diff% vs M-diff%) were analyzed using Wilcoxon signed rank tests, Deming regression, and Bland-Altman difference plots. RESULTS: Significant differences between methods were found for neutrophil and monocyte percentages in samples from dogs and cats and for eosinophil percentage in samples from cats. Correlations (r) (canine/feline) were .55/.72 for neutrophils, .76/.69 for lymphocytes, .05/.29 for monocytes and .60/.82 for eosinophils. Agreement between LC-diff% and Mdiff% results was poor in samples from both species. Bland-Altman plots revealed outliers in samples with atypical WBCs (1 cat), leukocytosis (2 dogs, 9 cats), and leukopenia (16 dogs, 11 cats). The LaserCyte generated error flags in 28 of 86 (32.6%) samples, included 7 with leukopenia, 8 with lymphopenia, 7 with leukocytosis, 1 with anemia, and 1 with erythrocytosis. When results from these 28 samples were excluded, correlations from the remaining nonflagged results (canine/feline) were .63/.65 for neutrophils, .67/.65 for lymphocytes, .11/.33 for monocytes, and .63/.82 for eosinophils. CONCLUSION: Although use of a 100-cell (vs 200-cell) M-diff% may be a limitation of our study, good correlation between WBC differentials obtained using the LaserCyte and the manual method was achieved only for feline eosinophils.