SUMMARYDogs infected with Angiostrongylus vasorum, a potentially lethal parasite parasitizing the heart and pulmonary arteries, may present severe respiratory, haematological and neurological signs. In this first large-scale seroepidemiological survey, 4003 sera originating from Germany and 4030 from the UK were tested by an ELISA for the detection of circulating antigen of A. vasorum, and by a separate ELISA detecting specific antibodies. In Germany, where mainly western federal states were sampled, 0·3% (n = 13, CI: 0·2–0·6%) of dogs were positive in both ELISAs, whereas in total 0·5% (n = 20, CI: 0·3–0·8%) were antigen-positive and 2·25% (n = 90, CI: 1·8–2·8%) were positive for specific antibodies. Regions with antigen- and antibody-positive animals were overlapping. In the UK, where mainly the south of the country was sampled, 0·97% (n = 39, CI: 0·7–1·3%) of dogs were antigen- and antibody positive. In total, 1·32% (n = 53, CI: 1·0–1·7%) were antigen-positive, and 3·2% (n = 129, CI: 2·7–3·8%) were positive for specific antibodies, again in overlapping regions. These results confirm the occurrence of A. vasorum in a random dog population originating from large parts of the countries investigated. The use of the tests alone or in combination was considered as a function of their sensitivities and specificities, in order to guide efficient clinical and epidemiological application.

BackgroundMicroscopic 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.ObjectiveCompare the performance of the SediVue with manual microscopy for detecting clinically relevant numbers of cells and 2 crystal types.SamplesFive‐hundred thirty urine samples (82% canine, 18% feline).MethodsFor 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).ResultsThe 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 ImportanceThe SediVue exhibits good agreement with manual microscopy for the detection of most formed elements evaluated, but improvement is needed for epithelial cells.

Background: Biologic variation of biochemical analytes, both within individuals and between individuals, determines whether population-based reference intervals (RIs) are appropriate when interpreting if a particular change is clinically relevant for a specific individual. Objectives: We aimed to evaluate the biologic variation of symmetric dimethylarginine (SDMA) in clinically healthy cats. Methods: A prospective, observational study was performed in which 10 clinically healthy, client-owned cats were sampled for serum biochemical analyses once weekly for 6 weeks. Serum samples were frozen, and then single batches were analyzed for SDMA, using both liquid chromatography-mass spectroscopy (LC-MS), and an enzyme multiplied immunoassay technique (EMIT), and creatinine by modified Jaffe method. Restricted maximum likelihood estimations were used to determine the coefficients of variation (CVs) describing variation within each cat, between cats, and the analytical variation. These CVs were used to determine the indices of individuality and reference change values (RCVs). Results: SDMA had an intermediate index of individuality that could be evaluated by both RCV and population-based RIs. In contrast, creatinine had a high index of individuality best evaluated with RCVs. Serum SDMA concentrations evaluated with either the reference standard, LC-MS, or the clinically used EMIT yielded similar results. Conclusions: Clinicians should consider biologic variation when selecting the best method for interpreting changes in biochemical analytes. Specifically, establishing each cat's baseline serum creatinine and SDMA concentrations during health, and applying RCVs to subsequent measurements could improve the recognition of meaningful biologic changes.

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. K E Y W O R D S Canine, urinalysis, urine 1 | INTRODUCTION Microscopic evaluation of urine provides invaluable information about the kidney and overall urogenital health of patients, as well as insight into other organ systems, and is a critical portion of the complete urinalysis profile. With proper sample collection, RBCs found within a urine sample could be attributed to sample collection (cystocentesis), trauma, inflammation, and neoplastic diseases within the urogenital tract, and less commonly, to coagulopathy. As in peripheral blood, WBCs in urine indicate inflammation or infection, specifically in the kidney or urogenital tract. 1 It is important to note that while very low numbers of RBCs or WBCs in a urine sample are considered normal, moderate to high numbers could indicate disease. 1-4 RBCs are usually smaller in size than WBCs and lack a nucleus and internal structures. Some types of white cells are similarin size and lack unique internal structures, which make distinguishing between these types of cells difficult. Acetic acid is recommended to lyse the RBCs when there is confusion. 5 Enumeration and morphologic qualification of these cells are required for a complete urine

Angiostrongylus vasorum was first described in dogs from south-western France in the nineteenth century. The life cycle of this nematode living in the heart and pulmonary arteries was also elucidated in France, leading to the byname "the French heartworm". Since then, its occurrence has been increasingly reported from various European countries, but little is known about its distribution in France. In this first large scale survey, 2289 sera from French dogs were collected for various reasons and tested using two distinct ELISAs for the detection of A. vasorum circulating antigen and of specific antibodies, respectively. As much as 1.14 % of the animals (n=26, 95 % confidence intervals, CI: 0.74-1.66 %) were positive by both ELISAs, while 0.61 % of the tested dogs (n=14, CI: 0.33-1.02 %) were antigen-positive and 2.01 % (n=46, CI: 1.47-2.67 %) were positive for specific antibodies. Regions where antigen-and antibodypositive animals came from were overlapping and distributed over the northern and southern parts of the country, while in central France relatively low numbers of positive dogs were detected. These results confirm the occurrence of A. vasorum in dogs originating from different parts of France. Early diagnosis with appropriate tools is essential to ensure adequate anthelmintic treatment, before the onset of fatal canine angiostrongylosis. It is therefore of great importance to improve our knowledge of the occurrence of A. vasorum and to maintain disease awareness. Original Article S32EndoparasitEs

Objectives The Catalyst One Chemistry Analyzer (IDEXX Laboratories) is a point-of-care instrument that can measure total thyroxine (TT4) by immunoassay. The aims of this study were to evaluate the analytic performance of the Catalyst TT4 assay in feline sera and to examine agreement of the Catalyst TT4 results with those measured by immunoassay at a veterinary reference laboratory. Methods Assay precision, reproducibility and linearity were evaluated for the Catalyst TT4 assay. For method comparison, TT4 concentrations in serum samples from 157 cats (127 hyperthyroid, 30 radioiodine-treated cats) were analyzed by both in-clinic and reference laboratory methods. Results The Catalyst TT4 demonstrated good precision and reproducibility (coefficients of variation ⩽8.5%) and excellent linearity in the diagnostic range of 6-150 nmol/l. Differences between the two TT4 methods showed no proportional or fixed bias (Bland-Altman plots) but did demonstrate greater spread of values at higher TT4 concentrations. Statistical analysis of percent differences between methods indicated 95% limits of agreement of ± 30%. When serum TT4 concentrations were classified as low, high or within the reference interval (12-50 nmol/l) for each assay, there was strong agreement (96.8%) in classification between methods. Conclusions and relevance The Catalyst TT4 assay provided precise serum TT4 concentrations in the 157 samples analyzed, which agreed well with results provided by a reference laboratory. Cats with Catalyst TT4 concentrations near decision thresholds (eg, normal vs high) should either have TT4 concentration repeated a few weeks later and/or undergo further testing (eg, free T4, serum thyroid-stimulating hormone, thyroid scintigraphy) to determine thyroid status.

Background No gold standard assay for serum total thyroxine (TT4) concentration in small animals exists. The Microgenics DRI TT4 (MTT4) assay is used by most reference laboratories. Hypothesis/Objectives IDEXX Catalyst Total T4 (CTT4) and Immulite 2000 TT4 (ITT4) results will agree with MTT4 results. Animals Residual small animal sera were randomized before reanalysis (dogs, CTT4 versus MTT4: n = 176, ITT4 versus MTT4: n = 74; cats, CTT4 versus MTT4: n = 319, ITT4 versus MTT4: n = 79). Methods Validation and method comparison study. Serum TT4 concentration was measured on all analyzers. Pairwise Pearson correlation, cumulative sum linearity test, regression, and Bland‐Altman method were performed. Results CTT4 versus MTT4 in dogs: constant bias (y‐intercept) was 0.10 μg/dL (95% confidence interval [CI], 0.05‐0.15), proportional bias (slope) was 0.86 μg/dL (95% CI, 0.83‐0.89); in cats, constant bias was 0.13 μg/dL (95% CI, 0.08‐0.20) and proportional bias was 1.01 μg/dL (95% CI, 0.98‐1.03), but the test for linearity failed. Bland‐Altman plots identified increasing disagreement with increasing serum TT4 concentrations. ITT4 versus MTT4 in dogs, constant bias was 0.14 μg/dL (95% CI, 0.04‐0.22) and 0.22 μg/dL (95% CI, 0.09‐0.33) for cats; proportional bias was 0.76 (95% CI, 0.72‐0.80) for dogs and 0.71 (95% CI, 0.69‐0.74) for cats. Conclusions and Clinical Importance Differences in CTT4 and MTT4 results affect interpretation at higher serum TT4 concentrations. The ITT4 proportional bias will underestimate serum TT4 concentrations in dogs and cats, compared to MTT4. Serial TT4 measurements should be done using the same assay.

Background: Subclinical bacteriuria is defined as a positive bacterial urine culture in the absence of clinical evidence of urinary tract infection (UTI). Studies have reported that hyperthyroid cats have UTIs (mostly subclinical) with prevalence rates of 12%-22%. Consequently, clinicians consider hyperthyroidism a risk factor for development of subclinical bacteriuria, and many recommend urine culture when evaluating hyperthyroid cats.Objectives: To compare the prevalence of subclinical bacteriuria (based on positive urine culture) in untreated hyperthyroid cats to that in euthyroid cats of similar age and sex.Animals: Three hundred and ninety-three hyperthyroid cats presented for radioiodine treatment and 131 euthyroid cats (≥7 years of age) presented for routine examination. Cats with signs of lower urinary tract disease were excluded.Methods: Prospective cohort study. Both hyperthyroid and euthyroid cats had urine collected by cystocentesis for complete urinalysis and culture. Data pertaining to age, sex, body condition, and serum thyroxine and creatinine concentrations also were acquired. Logistic regression was performed to evaluate for potential risk factors for subclinical bacteriuria.Results: Hyperthyroid cats showed a low prevalence of subclinical bacteriuria (4.3%), which did not differ from that found in euthyroid cats (4.6%). Of the signalment factors evaluated, only female sex was a significant risk factor (odds ratio [OR], 6.9; P = .002). Furthermore, positive urine cultures were more likely in specimens with dilute urine concentration (<1.035), pyuria, or microscopic bacteriuria.Conclusions and Clinical Importance: Hyperthyroid cats are not at risk for subclinical bacteriuria. In the absence of lower urinary tract signs, no clinical benefit exists in routinely performing urine cultures when evaluating hyperthyroid cats. K E Y W O R D S feline, hematuria, pyuria, subclinical bacteriuria, urinary tract infection, urine culture Abbreviations: cTSH, canine TSH; IQR, interquartile range; SDMA, serum symmetric dimethylarginine; T 4 , thyroxine; TSH, thyroid stimulating hormone; UTI, urinary tract infection.