Accuracy of the IDEXX SediVue Dx analyzer for quantifying RBC and WBC indices in the urine sediments of cats and dogs compared with manual microscopic evaluations.

BACKGROUND: The IDEXX SediVue Dx (SediVue) is an automated, in-clinic urine sediment analyzer for veterinary patients. The bias between the results from manual microscopy and the SediVue is currently unknown. OBJECTIVES: To assess the diagnostic accuracy of the SediVue, we aimed to determine the bias between the SediVue (index test) and manual microscopy (reference standard) for the quantification of RBCs and WBCs in urine. METHODS: Urine remnant samples were collected from cats and dogs that contained RBCs (n = 462) and WBCs (n = 510). Retrospective analysis of results from urine sediment examinations using both manual microscopy (using a KOVA and DeciSlide system) and the SediVue (1.0.1.3) was performed. Bias was determined with Bland-Altman plots. SediVue-captured images from high-bias samples were reviewed, and biases were compared. RESULTS: The median bias for semi-quantitative RBC and WBC counts was determined for RBC and WBC counts. The cutoffs were RBC ≤ 5/HPF, 0.3; RBC 5.1-10/HPF, 10.1; RBC 10.1-20/HPF, 10.6; and RBC > 20/HPF, 28.93; WBC ≤ 5/HPF, 0.1; WBC 5.1-10/HPF, 2.2; WBC 10.1-20/HPF, 9.4; and WBC > 20/HPF, 26.6. High bias between the methods was identified in 98 samples (21.0%) with RBCs and 77 samples (15.7%) with WBCs. Reviewer-based enumeration of the SediVue-captured images decreased the percentage of samples with high bias to 17.3% for RBCs and to 11.4% for WBCs. CONCLUSIONS: Bias in the RBC and WBC counts between manual microscopy and the SediVue was unlikely to impact clinical interpretations in a majority of cases. Although reviewer enumeration of SediVue-captured images reduced observed bias, inherent differences between methodologies appeared to have a larger impact on the bias.

Characterization of C-reactive protein in dogs undergoing medial patellar luxation surgery.

C-reactive protein (CRP) is a major acute phase protein used to monitor response to treatment during surgical recovery. Depending on the anatomical problem, surgery type and technique, the level of CRP can change drastically. The aim of this study was to describe the changes in CRP and white blood cell (WBC) levels following surgery for medial patellar luxation in otherwise healthy dogs. Twenty-two dogs completed the study. CRP was measured using a commercially available dry chemistry slide on a commercially available in-clinic analyser. Analyses were performed using the Wilcoxon Rank Sum test and a mixed effects Poisson regression model. A significant change in CRP levels was found between the pre-anesthetic and 24 hr post-surgical timepoint with a median difference of 92.0 mg/dL (P < 0.001). Though a median drop in the CRP value of 13.9 mg/dL was observed between the 24 hr and 48 hr post-surgical time period, the result was not statistically significant (P = 0.456). Similarly, there was a significant increase in WBC between the pre-anesthetic and 24-hr post-surgical time point (P < 0.001) followed by a significant decrease in WBC between the 24 hr and 48-hr post-surgical time points (P = 0.015). In this study population, CRP levels were observed to aid in monitoring of the overall health of the dogs following surgery for medial patellar luxation. The results of this study suggest that both CRP and WBC values significantly increase by 24 hr but where CRP levels remain elevated through 48 hr post-surgery, WBC showed a significant drop between 24 and 48 hr. Further investigation into the length of time for both CRP and WBC to reach basal levels in this particular type of surgery would be of value to monitor recovery from surgery.

Comparison of the performance of the IDEXX SediVue Dx® with manual microscopy for the detection of cells and 2 crystal types in canine and feline urine.

BACKGROUND: Microscopic evaluation of urine is inconsistently performed in veterinary clinics. The IDEXX SediVue Dx® Urine Sediment Analyzer (SediVue) recently was introduced for automated analysis of canine and feline urine and may facilitate performance of urinalyses in practice. OBJECTIVE: Compare the performance of the SediVue with manual microscopy for detecting clinically relevant numbers of cells and 2 crystal types. SAMPLES: Five-hundred thirty urine samples (82% canine, 18% feline). METHODS: For SediVue analysis (software versions [SW] 1.0.0.0 and 1.0.1.3), uncentrifuged urine was pipetted into a cartridge. Images were captured and processed using a convolutional neural network algorithm. For manual microscopy, urine was centrifuged to obtain sediment. To determine sensitivity and specificity of the SediVue compared with manual microscopy, thresholds were set at ≥5/high power field (hpf) for red blood cells (RBC) and white blood cells (WBC) and ≥1/hpf for squamous epithelial cells (sqEPI), non-squamous epithelial cells (nsEPI), struvite crystals (STR), and calcium oxalate dihydrate crystals (CaOx Di). RESULTS: The sensitivity of the SediVue (SW1.0.1.3) was 85%-90% for the detection of RBC, WBC, and STR; 75% for CaOx Di; 71% for nsEPI; and 33% for sqEPI. Specificity was 99% for sqEPI and CaOx Di; 87%-90% for RBC, WBC, and nsEPI; and 84% for STR. Compared to SW1.0.0.0, SW1.0.1.3 had increased sensitivity but decreased specificity. Performance was similar for canine versus feline and fresh versus stored urine samples. CONCLUSIONS AND CLINICAL IMPORTANCE: The SediVue exhibits good agreement with manual microscopy for the detection of most formed elements evaluated, but improvement is needed for epithelial cells.

Urine sediment examination: Potential impact of red and white blood cell counts using different sediment methods.

BACKGROUND: Centrifugation is the primary method used to perform urine sediment analyses, but evaluation of other methods is required to validate centrifugation. OBJECTIVES: Non-urine materials were used to examine the repeatability (precision) and effectiveness (recovery) of four sediment methodologies on red blood cell (RBC) and white blood cell (WBC) counts. METHODS: Four urine sediment methods were compared using commercially available quality control material (QCM) and fresh canine RBCs in a diluent. Treatments included (a) 5 mL centrifugation at 390g for 5 minutes; (b) 1.5 mL centrifugation at 3900g for 45 seconds; (c) 60 µL of neat (unspun urine) in a microtiter well; and (d) 30 µL of neat on a slide with a coverslip. A within-run precision using QCM was followed by a one-run comparison test performed with a suspension of canine erythrocytes. RBC morphology was also examined. RESULTS: All results are listed in order of Methods A-D. Percent coefficients of variation (%CVs) for WBCs were 23.2%, 33.7%, 15.0%, and 27.2%. Red blood cells %CVs were 34.3%, 29.2%, 16.2%, and 24.4%. Average WBC counts in ten fields of view (FOV) ± 1 SD were 26.4 ± 6.1, 14.2 ± 4.8, 32.8 ± 4.9, and 1.6 ± 0.4. Average RBC counts in 10 fields of view (FOV) ± 1 SD were 45.3 ± 15.5, 23.9 ± 7.0, 38.4 ± 6.2, and 2.6 ± 0.6. The one-run comparison test reports average RBC counts per FOV at 55.2, 23.4, 92.8, and 13.8. The percentages of abnormal RBCs were 92.2%, 74.8%, 7.0%, and 55.1%. CONCLUSIONS: Method C had the best reproducibility, a lower frequency of cell morphology abnormalities, and similar cellular counts to those of Methods A and B.

Evaluation of reticulocyte hemoglobin content (RET-He) in the diagnosis of iron-deficient erythropoiesis in dogs.

BACKGROUND: Reticulocyte hemoglobin content provided by the Siemens ADVIA (CHr) is an established marker of iron deficiency. The IDEXX ProCyte Dx hematology analyzer now provides a similar variable, reticulocyte hemoglobin equivalent (RET-He). OBJECTIVES: The objective was to evaluate RET-He and its diagnostic utility in dogs, and to calculate a cutoff value for diagnosing iron-deficient erythropoiesis (IDE). Furthermore, the prevalence of RET-He values below this cutoff value was established. METHODS: One hundred and seventy-one CBCs of healthy dogs were used to establish a RI. Stability of RET-He was evaluated by repeated measurements over 48 hours (n = 10). The 25-run coefficient of variation (CV) was calculated, and correlation and bias between measurements of RET-He and CHr were assessed (n = 190). A cutoff value for diagnosing IDE was calculated. The utility of RET-He in the detection of IDE was evaluated in 123 dogs. The prevalence of low RET-He values was assessed retrospectively in a multicenter study (2012-2014) under participation of 7 veterinary clinics. RESULTS: Reticulocyte hemoglobin equivalent with an RI of 22.2 to 28.6 pg was statistically stable over 48 hours (P = .10). The CV was 1.8%. A fair correlation (ρ = 0.74) between RET-He and CHr with a small bias of -0.6 pg was found. The cutoff value for diagnosing IDE was 20.9 pg (sensitivity: 85%; specificity: 99%). The prevalence of RET-He values below 20.9 pg was 10.3% (1084/10,553 dogs). CONCLUSIONS: RET-He on the ProCyte Dx is a precise screening tool in dogs to detect iron-deficient erythropoiesis.

Canine reticulocyte hemoglobin content (RET-He) in different types of iron-deficient erythropoiesis.

BACKGROUND: Reticulocyte hemoglobin content (RET-He) is a diagnostic marker for iron deficiency (ID) in people and dogs. OBJECTIVES: The aim of our study was to evaluate the clinical utility of RET-He in the diagnosis of different causes of iron-deficient erythropoiesis (IDE). METHODS: Canine CBCs were separated into 2 groups according to RET-He values, < 20.9 pg or ≥ 20.9 pg. Erythrocyte and reticulocyte variables were compared between dogs with decreased and normal RET-He values. Additional data for a subgroup of dogs were collected, and dogs with low RET-He values were categorized as having ID, inflammatory disorders (INFL), portosystemic shunt (PSS), miscellaneous diseases (MISC), or combinations of these diseases (ID+INFL, ID+PSS). Hematologic variables were compared between dogs of the different disease groups. RESULTS: Overall, 10.3% (1084/10,553) of canine CBCs showed decreased RET-He values. Significant differences between dogs with decreased and normal RET-He values were found for all erythrocyte and reticulocyte variables. The majority (68.9%, 747/1084) of dogs with low RET-He values was anemic; 28.9% (216/747) of those anemic dogs had microcytosis and hypochromasia. In the subgroup of dogs, 8.9% (205/2306) had low RET-He values. According to their diagnosed diseases, anemic dogs (138/205) could be categorized as ID (17/138; 12.3%), INFL (16/138; 11.6%), PSS (30/138; 21.7%), ID+INFL (63/138; 45.7%), ID+PSS (8/138; 5.8%), and MISC (4/138; 2.9%). Distribution in nonanemic dogs (67/205) was similar, except for a lower number of dogs with PSS. CONCLUSIONS: Low RET-He values indicate IDE even in dogs with other CBC variables within the RIs.

Patient-based feedback control for erythroid variables obtained using in-house automated hematology analyzers in veterinary medicine.

BACKGROUND: Automated in-house diagnostic analyzers, most commonly used for hematologic and biochemical analysis, are typically calibrated, and then control materials are used to confirm the quality of results. Although this approach provides indirect knowledge that the system is performing correctly, it does not provide direct knowledge of system performance between control runs. OBJECTIVES: The objectives of this study were to apply analysis of weighted moving averages to assess performance of hematology analyzers using animal patient samples from dogs, cats, and horses as they were analyzed and apply correction factors to mitigate instrument-driven biases when they developed. METHODS: A set of algorithms was developed and applied to sequential batches of 20 samples. Repeated samples within a batch and large populations of samples with similar abnormalities were excluded. Data for 6 hematologic variables were grouped into batches of weighted moving averages; data were analyzed with control chart rules, a gradient descent algorithm, and fuzzy logic to define and apply adjustments. RESULTS: A total of 102 hematology analyzers that had developed biases in RBC count, HCT, hemoglobin (HGB) concentration, MCV, MCH, and MCHC were evaluated. Following analysis, all variables except HGB concentration required adjustment, with RBC counts requiring only slight change and MCV requiring the greatest change. Adjustments were validated by comparing PCVs with the original and adjusted HCT values. CONCLUSIONS: The proposed system provides feedback control to minimize system bias for RBC count, HCT, HGB concentration, MCV, MCH, and MCHC. Fundamental assumptions must be met for the approach to assure proper functionality.

Advances in hematology analyzers.

The complete blood count is one of the basic building blocks of the minimum database in veterinary medicine. Over the past 20 years, there has been a tremendous advancement in the technology of hematology analyzers and their availability to the general practitioner. There are 4 basic methodologies that can be used to generate data for a complete blood count: manual methods, quantitative buffy coat analysis, automated impedance analysis, and flow cytometric analysis. This article will review the principles of these methodologies, discuss some of their advantages and disadvantages, and describe some of the hematology analyzers that are available for the in-house veterinary laboratory.

Effect of anticonvulsant dosages of potassium bromide on thyroid function and morphology in dogs.

A placebo-controlled experiment was performed to evaluate the effect of potassium bromide on the canine thyroid gland. Basal total thyroxine, free thyroxine, and basal thyrotropin serum concentrations were evaluated over a 6-month period in potassium bromide-treated and control dogs. A thyrotropin-releasing hormone stimulation test was also performed in all dogs at the beginning and conclusion of the study. Thyroid histopathology was compared between treated and control dogs at the end of the study. No difference was detected in any parameter between the two groups at the end of the study. A decline in thyroid hormone concentrations over the course of the study did occur in both groups of dogs. Potassium bromide does not appear to have a significant effect on canine thyroid function or morphology.

Prognosis following surgical excision of canine cutaneous mast cell tumors with histopathologically tumor-free versus nontumor-free margins: a retrospective study of 31 cases.

The purpose of this study was to determine if the presence of histopathologically tumor-free versus nontumor-free margins was prognostic for relapse or tumor-related death in dogs following surgical excision of single or multiple cutaneous mast cell tumors confined to the skin without evidence of metastasis to lymph nodes or other noncutaneous sites. Differences in tumor-related death or frequency of relapse between the two groups were not significant. Failure to achieve histopathological tumor-free margins frequently did not lead to local relapse. All tumor-related deaths occurred following local relapse. The lack of statistical support for an association between prognosis and histopathological tumor-free versus nontumor-free margins may be a result of small sample size.

Evaluation of treatment with doxorubicin and piroxicam or doxorubicin alone for multicentric lymphoma in dogs.

OBJECTIVE: To evaluate the antitumor and toxic effects of treatment with doxorubicin combined with piroxicam or doxorubicin alone for multicentric lymphoma in dogs. DESIGN: Nonrandomized clinical trial. ANIMALS: 75 dogs with multicentric lymphoma. PROCEDURE: 33 dogs were treated with doxorubicin (30 mg/m2, IV, q 21 d, for 3 doses) and piroxicam (0.3 mg/kg [0.14 mg/lb], PO, q 24 h); results were compared with a historical control group of 42 dogs treated with doxorubicin (30 mg/M2, IV, q 21 d, for 3 doses) alone. Results-The percentages of dogs that had remission with doxorubicin-piroxicam treatment (79%) or doxorubicin treatment alone (74%) were not significantly different. Median duration of first remission was 130 days with doxorubicin-piroxicam and 147 days with doxorubicin alone; these values were not significantly different. Severe toxicosis was observed in 22% of dogs treated with doxorubicin-piroxicam and 17% of dogs treated with doxorubicin alone. CONCLUSIONS AND CLINICAL RELEVANCE: Both treatment protocols were efficacious and well tolerated. The doxorubicin-piroxicam treatment was no more effective regarding response rate, remission duration, or survival duration, compared with the control group treated with doxorubicin alone.

Subcutaneous emphysema, pneumomediastinum, and pulmonary emphysema in a young schipperke.

A 4-month-old, intact female schipperke was presented for evaluation and treatment of subcutaneous (SC) emphysema. Radiographs revealed pneumomediastinum and SC emphysema. Sequential radiographs confirmed a worsening of the SC emphysema. Extensive, nonsurgical evaluation failed to reveal the source of the air within the mediastinum. Exploratory thoracotomy revealed an emphysematous right middle lung lobe. Lobectomy of the right middle lung lobe resolved both the pneumomediastinum and SC emphysema. Histopathological evaluation confirmed pulmonary emphysema. A variation of congenital pulmonary emphysema was considered in this case.

Babesia gibsoni infection in a dog from indiana.

A 10-year-old spayed female mixed-breed dog was presented to the Purdue University Veterinary Teaching Hospital (PUVTH) with complaints of persistent anemia with occasional exacerbations, anorexia, and lethargy. The dog had been presented to the referring veterinarian 2 months prior with multiple bite wounds received during a fight with 3 Pit Bull Terriers. The dog was discharged after the wounds were cleaned and surgically closed. Upon admission to the PUVTH, blood was collected for a complete blood count and biochemical analysis. Microscopic examination of peripheral blood smears revealed intraerythrocytic protozoal parasites consistent with Babesia gibsoni. Molecular analysis confirmed that the organism was B. gibsoni and that its 18S ribosomal RNA sequence was identical to that of other B. gibsoni isolates from Oklahoma, North Carolina, and Okinawa, Japan. Hematologic changes included moderately severe, regenerative, macrocytic, normochromic anemia, with poikilocytosis, polychromasia, anisocytosis, and a marked increase in nucleated RBCs. Biochemical changes included increased serum alanine aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase activities. The dog was treated with imidocarb, but despite initial clinical improvement, the dog died 2 weeks after the first dose. A necropsy was not performed. The infection in this dog is the first reported case of B. gibsoni infection in Indiana. Because of the widespread geographical distribution of the organism, veterinarians and veterinary clinical pathologists throughout the United States should carefully examine Romanowsky-stained blood smears from patients with acute hemolytic anemia for small intraerythrocytic babesial parasites.

Sensitivity and specificity of cytologic evaluation in the diagnosis of neoplasia in body fluids from dogs and cats.

Sensitivity and specificity were determined for the cytologic detection of malignant tumors in canine and feline body cavity effusions. In a prospective study, 424 body cavity effusions from dogs and cats were collected and evaluated, including 70 pleural and 163 peritoneal effusions from dogs, and 77 pleural and 114 peritoneal effusions from cats. Final diagnoses were confirmed in 339 of the 424 cases by clinical follow-up, necropsy, and in the case of malignant tumors, Histopathology. Malignant tumors were found in 18% of canine and 25% of feline body cavity effusions. Approximately one-half of tumors in both dogs and cats were carcinomas. Discrete cell tumors accounted for 56% of feline neoplastic effusions. The sensitivity of cytologic evaluation for the detection of malignant tumors in body cavity effusions was 64% for dogs and 61% for cats. Specificity was 99% for canine and 100% for feline effusions. Sensitivity and specificity were comparable to those obtained with cytologic evaluation of human samples.

Cerebrospinal fluid response following metrizamide myelography in normal dogs: effects of routine myelography and postmyelographic removal of contrast medium.

The effect of metrizamide myelography on 90-minute postmyelographic cerebrospinal fluid (CSF) samples was evaluated in a paired crossover study in 16 normal dogs. Each dog received a routine cervical myelogram (nonwithdrawal myelography) and a myelogram followed by contrast medium removal via aspiration from the subarachnoid space (withdrawal myelogram). Following nonwithdrawal myelography, the CSF was characterized by mild inflammation with a mixed pleocytosis and increased protein concentration. Compared with the nonwithdrawal CSF samples, the postmyelographic CSF of the withdrawal dogs had a more severe inflammatory response with significant increases (p < 0.05) in absolute numbers of neutrophils, monocytoid cells, eosinophils, lymphocytes, and protein concentration. The withdrawal procedure may have contributed an additional mechanical effect on the leptomeninges producing the more severe inflammatory response in the withdrawal dogs. Although seizure data are not reported here, postmyelographic seizures were more frequent following non-withdrawal myelography as compared with withdrawal myelography (p < 0.05), suggesting a decrease in metrizamide-induced neurotoxicity for the withdrawal dogs.