Silica and barium: Comparison of microscopic appearance and characterization of effects of silica on cytomorphology.

BACKGROUND: Silica from plastic red top sample collection tubes and barium cause recognized artifacts in slide preparations for microscopic examination. OBJECTIVES: The objectives of this study were to evaluate and directly compare the microscopic appearance of silica and barium particles and various slide preparation techniques (e.g., use of coverslips, oil immersion, and different stains). A secondary objective of this study was to evaluate the effects of silica particles on cellular morphology after mechanical trauma with cytocentrifugation. METHODS: Fluid samples (deionized water, pleural effusion, peritoneal effusion, cerebrospinal fluid, and urine) were collected and evaluated in silica- and non-silica-containing tubes. Barium was added to silica and non-silica samples. Direct and cytocentrifuge preparations were compared to evaluate the effect of silica particles on cellular morphology. Preparations were stained with Wright-Giemsa, rhodizonic acid disodium salt, Alizarin Red, Grocott's methenamine silver, and Prussian blue. RESULTS: Silica and barium particles were identifiable via light microscopy with and without polarized light, although silica particles diminished with immersion oil. Barium particles retained their structure and diminished less under oil. Cytoseal mounting medium for coverslip placement resulted in diminished refractility of silica and some barium particles. Silica particles with mechanical interaction during cytocentrifugation resulted in disrupted cellular morphology with many lysed cells. Silica and barium particles were negative for all special stains tested. CONCLUSIONS: Silica from plastic red top tubes adversely affects cell morphology in cytocentrifuge preparations, potentially affecting manual differential cell counts and compromising diagnostic interpretation. Samples intended for microscopic evaluation should not be collected in silica-containing tubes.

Successful multimodal treatment of extreme hypertriglyceridemia in a juvenile diabetic dog.

OBJECTIVE: To describe the therapeutic protocol used to normalize severe hypertriglyceridemia in a dog. CASE SUMMARY: A 7-month-old, 1.2-kg female Pomeranian presented with acute polyuria, polydipsia, and ocular discoloration. Diagnoses included diabetic ketosis, severe hypertriglyceridemia (>225 mmol/L [>20,000 mg/dl]), lipemia retinalis, and bilateral uveitis. The triglyceride concentration was near normal within 2 days of initiating treatment with fenofibrate, regular insulin constant rate infusion (CRI), manual therapeutic plasma exchange (TPE), and a low-fat diet. All clinical signs resolved. The dog has had no relapse of hypertriglyceridemia at the time of writing the manuscript, 6 months later, with continued treatment of diabetes mellitus. NEW OR UNIQUE INFORMATION PROVIDED: This is the first case report documenting the combination of fenofibrate, insulin CRI, and manual TPE for treatment of severe hyperlipidemia in a dog. Detailed protocols for manual TPE and a novel insulin CRI are provided. A discussion of multiple spurious biochemical and hematologic errors associated with the severe hypertriglyceridemia is also provided.

Comparison of biochemical and hematologic values obtained via jugular venipuncture and peripheral intravenous catheters in dogs.

BACKGROUND: Sampling from a peripheral intravenous catheter (PIVC) might be a more efficient and less traumatic collection of blood for serum biochemistry (SB) or CBC than direct venipuncture (DV). Agreement between results of samples obtained by these methods has not been evaluated in dogs. OBJECTIVES: The primary objectives were to determine whether sampling from PIVC could be used in place of DV for dogs. We hypothesized DV and PIVC samples would have clinically equivalent SB and CBC results. ANIMALS: Sixty-one client-owned dogs were included in each study arm. METHODS: This was a partially randomized method-comparison study. Paired DV and PIVC samples obtained within 1 to 2 minutes after, or approximately 24 hours after, placement of a PIVC in a cephalic vein were evaluated for agreement and bias using percentage difference plots (with a priori application of consensus total allowable error), Bland-Altman analysis, Passing-Bablok regression analysis, Wilcoxon signed rank test, and McNemar's test. RESULTS: There was statistically and clinically acceptable agreement and no bias between sampling methods for the majority of results. Analytes with the most frequent disagreement were aspartate aminotransferase, total bilirubin, potassium, bicarbonate, and leukocyte differential counts, as well as red blood cell count, hemoglobin, hematocrit, and packed cell volume in the hospitalized PIVC sampling group. Few observed differences would change clinical decision making. CONCLUSIONS AND CLINICAL IMPORTANCE: PIVC sampling can provide generally acceptable SB and CBC results for most dogs, but clinicians should be aware of a few values for which disparate results might occasionally be obtained.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Cytologic, histopathologic, and clinical features of granulomatous colitis in a French Bulldog.

A young French Bulldog was presented with clinical signs of chronic gastrointestinal disease, unresponsive to medical therapies. Parasite screenings and abdominal ultrasound failed to identify the etiology of the clinical signs. Cytologic evaluation of a rectal scraping sample diagnosed presumptive granulomatous colitis (GC) based on the presence of numerous macrophages with characteristic abundant, pink, granular cytoplasm, which showed an intense pink color when stained with periodic acid-Schiff. Tissue biopsy samples and Escherichia coli fluorescence in situ hybridization analysis confirmed the cytologic diagnosis. The cytologic, histopathologic, and clinical features and staining properties of GC in a French Bulldog are reported. Rectal scraping should be considered a part of the diagnostic evaluation in patients with suspected GC.

Fluid Analysis in the Equine Patient: Cerebrospinal, Synovial, and Peritoneal Fluids.

Fluid analysis is an important part of the diagnostic work-up of equine patients presenting with disorders of the nervous system, musculoskeletal system, and abdominal cavity. Proper specimen handling and processing are paramount for complete and accurate interpretation of fluid samples. Normal cerebrospinal fluid is a low-cellularity, low-protein fluid requiring specific sample handling to ensure accurate results. Joint and abdominal fluid analyses are completed in practice or submitted for analysis to a reference laboratory. This article discusses fluid sample handling and processing considerations for the equine practitioner and reviews cytologic evaluation of normal and abnormal cerebrospinal, synovial, and peritoneal fluid samples.

Primary Hyperparathyroidism in a Quarter Horse Mare Associated With a Chief Cell Adenoma.

Primary hyperparathyroidism is rare in large animal species, and little is known regarding its pathophysiology, endocrine and electrolyte derangements, diagnosis, medical management, and prognosis. This report describes the clinicopathologic diagnosis of a parathyroid (PT) gland chief cell adenoma in a 12-year-old Quarter Horse mare, including PT hormone (PTH) and electrolyte disarrangements associated with the neoplasia, the surgical removal of the adenoma, and medical management of the case. This report also describes for the first time the use PTH immunohistochemistry to confirm the nature of this neoplasia in a horse.

Agreement of 2 electrolyte analyzers for identifying electrolyte and acid-base disorders in sick horses.

BACKGROUND: Use of different analyzers to measure electrolytes in the same horse can lead to different interpretation of acid-base balance when using the simplified strong ion difference (sSID) approach. OBJECTIVE: Investigate the level of agreement between 2 analyzers in determining electrolytes concentrations, sSID variables, and acid-base disorders in sick horses. ANIMALS: One hundred twenty-four hospitalized horses. METHODS: Retrospective study using paired samples. Electrolytes were measured using a Beckman Coulter AU480 Chemistry analyzer (PBMA) and a Nova Biomedical Stat Profile (WBGA), respectively. Calculated sSID variables included strong ion difference, SID4 ; unmeasured strong ions, USI; and total nonvolatile buffer ion concentration in plasma (Atot ). Agreement between analyzers was explored using Passing-Bablok regression and Bland-Altman analysis. Kappa (κ) test evaluated the level of agreement between analyzers in detecting acid-base disorders. RESULTS: Methodologic differences were identified in measured Na+ and Cl- and calculated values of SID4 and USI. Mean bias (95% limits of agreement) for Na+ , Cl- , SID4 , and USI were: -1.2 mmol/L (-9.2 to 6.8), 4.4 mmol/L (-4.4 to 13), -5.4 mmol/L (-13 to 2), and -6.2 mmol/L (-14 to 1.7), respectively. The intraclass correlation coefficient for SID4 and USI was .55 (95%CI: -0.2 to 0.8) and .2 (95%CI: -0.15 to 0.48), respectively. There was a poor agreement between analyzers for detection of SID4 (κ = 0.20, 95%CI, 0.1 to 0.31) or USI abnormalities (κ = -0.04, 95%CI, -0.11 to 0.02). CONCLUSIONS AND CLINICAL IMPORTANCE: Differences between analyzer methodology in measuring electrolytes led to a poor agreement between the diagnosis of acid-base disorders in sick horses when using the sSID approach.

RENAL NEOPLASIA FROM A SINGLE POPULATION OF PTEROPODID BATS.

Neoplastic diseases have rarely been reported in the family Pteropodidae, and primary malignant renal neoplasms are generally uncommon across animal species. This case series describes four cases of primary renal neoplasia: three renal cell carcinomas and one nephroblastoma in three species of pteropodid bats, specifically large flying foxes (Pteropus vampyrus, n = 2), straw-colored fruit bat (Eidolon helvum, n = 1), and a little golden-mantled flying fox (Pteropus pumilus, n = 1). Two of the cases were diagnosed antemortem using ultrasonography, computed tomography, and cytology; and one of these bats with a renal cell carcinoma was treated successfully with a unilateral nephrectomy. The remaining two cases were diagnosed at necropsy.

Cytologic features and staining characteristics of Gamna-Gandy bodies from seven canine fine-needle aspirate preparations.

Gamna-Gandy (GG) bodies are non-infectious, hyphal-like structures associated with siderotic nodules in lymphoid tissue; GG bodies are very rarely reported in veterinary cytologic samples. Cytologically, GG bodies can be misidentified as hyphae or plant material. Seven canine lymphoid tissue aspiration cases that contained GG bodies were investigated for morphologic variability and staining characteristics. Available archived cytology slides containing GG bodies were stained with reagents known to show positive results (Prussian blue, Alizarin red S, Von Kossa) and negative results (Gomori methenamine silver) in histologic samples. Calcofluor white staining was also performed. GG bodies in Wright-Giemsa-stained cytology samples displayed considerable variability but were generally 2-5 µm diameter, 10-35 µm long, refractile, clear, pale-tan or pale-yellow, wavy or straight, tubular structures. Six cases allowed for cytochemical staining; staining properties were similar to histology samples. The bodies did not stain with calcofluor white; this stain may be helpful in distinguishing GG bodes from fungal hyphae.

Presumed lupus erythematosus cells identified in bronchoalveolar lavage fluid from a Mexican Hairless dog.

A neutered male Mexican Hairless dog was presented for generalized weight loss and weakness. Initial laboratory testing and diagnostic imaging revealed thrombocytopenia and an interstitial to miliary lung pattern affecting all lung fields. Mild joint effusion was found on physical examination affecting the stifle, tarsal, carpal, and elbow joints. Examination of synovial fluid demonstrated an inflammatory polyarthropathy in 3 joints. Cytocentrifuged and direct preparations of the bronchoalveolar lavage (BAL) fluid sample were made and cells consistent with lupus erythematosus (LE) cells and ragocytes were found. Based on these findings, the anti-nuclear antibody (ANA) titer was determined as 1:640. A clinical diagnosis of systemic LE was made based on the satisfaction of 2 major criteria (thrombocytopenia and inflammatory polyarthritis), 4 minor criteria (central nervous system signs, lymphadenopathy, fever of unknown origin, and pleuritis), positive ANA titer, and the identification of presumed LE cells in BAL fluid. This case report highlights a novel finding of LE cells in respiratory secretions and provides a review of diagnostic criteria of systemic LE.