Diagnostic quality of ultrasound-guided fine-needle aspirates samples from the canine liver and spleen is not significantly affected by using 22-, 23-, and 25-gauge needles.

Ultrasound-guided fine-needle aspirates (FNA) of the liver and spleen for cytological analysis are a commonly performed procedure in canine veterinary practice. Based on our review of the literature, this is the first published study investigating whether needle size affects the diagnostic quality of hepatic and splenic samples. The aim of this prospective analytical study was to compare the diagnostic quality of ultrasound-guided FNA cytological samples of canine liver and spleen based on cellularity, blood contamination, and overall cell preservation between three different needle sizes (22-, 23-, and 25-gauge). A total of 282 splenic aspirates from 94 dogs and 348 hepatic aspirates from 116 dogs were enrolled in the study and examined by two board-certified veterinary clinical pathologists. In this study, no significant differences in diagnostic quality were identified between different needle gauge sizes when sampling canine liver and spleen. Blood contamination was higher using 22-gauge needles compared with 25-gauge needles (P = 0.024) when sampling the liver.

Clinical and clinicopathological features and outcomes of cats with suspected dietary induced pancytopenia.

BACKGROUND: After a strong epidemiological link to diet was established in an outbreak of pancytopenia in cats in spring 2021 in the United Kingdom, 3 dry diets were recalled. Concentrations of the hemato- and myelotoxic mycotoxins T-2, HT-2 and diacetoxyscirpenol (DAS) greater than the European Commission guidance for dry cat foods were detected in the recalled diets. OBJECTIVES: To describe clinical and clinicopathological findings in cats diagnosed with suspected diet induced pancytopenia. ANIMALS: Fifty cats presenting with pancytopenia after exposure to a recalled diet. METHODS: Multicenter retrospective case series study. Cats with known exposure to 1 of the recalled diets were included if presented with bi- or pancytopenia and underwent bone marrow examination. RESULTS: Case fatality rate was 78%. Bone marrow aspirates and biopsy examination results were available in 23 cats; 19 cats had a bone marrow aspirate, and 8 cats had a biopsy core, available for examination. Bone marrow hypo to aplasia-often affecting all cell lines-was the main feature in all 31 available core specimens. A disproportionately pronounced effect on myeloid and megakaryocytic cells was observed in 19 cats. Myelofibrosis or bone marrow necrosis was not a feature. CONCLUSION AND CLINICAL IMPORTANCE: Mycotoxin induced pancytopenia should be considered as differential diagnosis in otherwise healthy cats presenting with bi- or pancytopenia and bone marrow hypo- to aplasia.

Deep Learning-Based Quantification of Pulmonary Hemosiderophages in Cytology Slides.

Exercise-induced pulmonary hemorrhage (EIPH) is a common condition in sport horses with negative impact on performance. Cytology of bronchoalveolar lavage fluid by use of a scoring system is considered the most sensitive diagnostic method. Macrophages are classified depending on the degree of cytoplasmic hemosiderin content. The current gold standard is manual grading, which is however monotonous and time-consuming. We evaluated state-of-the-art deep learning-based methods for single cell macrophage classification and compared them against the performance of nine cytology experts and evaluated inter- and intra-observer variability. Additionally, we evaluated object detection methods on a novel data set of 17 completely annotated cytology whole slide images (WSI) containing 78,047 hemosiderophages. Our deep learning-based approach reached a concordance of 0.85, partially exceeding human expert concordance (0.68 to 0.86, mean of 0.73, SD of 0.04). Intra-observer variability was high (0.68 to 0.88) and inter-observer concordance was moderate (Fleiss' kappa = 0.67). Our object detection approach has a mean average precision of 0.66 over the five classes from the whole slide gigapixel image and a computation time of below two minutes. To mitigate the high inter- and intra-rater variability, we propose our automated object detection pipeline, enabling accurate, reproducible and quick EIPH scoring in WSI.

Clonality testing in the lymph nodes from dogs with lymphadenomegaly due to Leishmania infantum infection.

INTRODUCTION: In southern European countries, multicentric lymphoma and leishmaniosis are the main differential diagnoses in dogs presented with generalized lymphadenomegaly. The cytological examination is in some cases inconclusive and polymerase chain reaction (PCR) for antigen receptor rearrangement (PARR) has become a common method to confirm or rule out a lymphoproliferative neoplasia. According to the literature, leishmaniosis may lead to clonal arrangements and therefore to a false diagnosis of lymphoma, but this assumption is made from a single leishmania infected dog. Therefore, the objective of this study was to prospectively evaluate results from PARR in dogs with lymphadenomegaly due to clinical leishmaniosis at the moment of diagnosis. MATERIALS AND METHODS: 31 dogs with a diagnosis of leishmaniosis based on the LeishVet guidelines were included in the study. Samples from enlarged lymph nodes were taken for cytological examination, clonality testing and Leishmania infantum PCR. RESULTS: All 31 dogs had medium to high positive antibody titers against Leishmania spp. and 30/31 had a positive Leishmania PCR from the lymph node. A polyclonal arrangement for B cells (immunoglobulin heavy chain gene) and T cells (T-cell receptor gamma chain gene) antigen receptors was found in 28/31 dogs. Two out of 31 dogs showed a monoclonal arrangement for Ig with high (1:2) and low (1:7) polyclonal background respectively; and one of the 31 dogs showed a monoclonal arrangement for T cell receptor with low (1:3) polyclonal background. CONCLUSION: Infections with Leishmania infantum resulted in clonal rearrangement, and therefore in a possible false diagnosis of lymphoma, in 3 out of 31 dogs (9.7%). Although, PARR is a useful method to differentiate lymphoma from reactive lymphoid hyperplasia in dogs with leishmaniosis, mono-/biclonal results should be interpreted carefully, especially in the presence of any degree of polyclonal background, and together with other clinicopathological findings.

Validation of an enzyme-linked immunosorbent assay for measurement of feline haptoglobin.

Haptoglobin is a positive moderate acute phase protein (APP) in cats. Measurement of haptoglobin can be used in the diagnosis, prognosis, and monitoring of systemic inflammatory disease, especially by creating profiles with major APPs. The aim of our study was to validate a sandwich enzyme-linked immunosorbent assay (ELISA) for measurement of feline haptoglobin. The validation included an assessment of precision, accuracy, detection limit, method comparison with a spectrophotometric assay, and evaluation of the overlap performance. The concentration of haptoglobin was measured in serum from 27 healthy and 23 sick cats. The coefficients of variation were 2.5-4.7% for intra-assay variability and 7.1-11.6% for interassay variability. The ratio of observed to expected dilutional parallelism of 4 serum samples was 108.1-118.4%. The ratio of observed to expected spike recovery of 4 serum samples was 90.8-94.0%. The lower detection limit was 0.19 g/L. Method comparison revealed a positive correlation (rs = 0.949, P < 0.0001) and a proportional bias between the methods of -38.9%. Agreement between the methods was not clinically acceptable. Overlap performance of the ELISA was deemed satisfactory. The sandwich ELISA measures feline haptoglobin with an analytical and overlap performance acceptable for clinical purposes. Given the observed bias, the ELISA cannot be used interchangeably with the spectrophotometric assay.

Evaluation of three different point-of-care tests for quantitative measurement of canine C-reactive protein.

BACKGROUND: C-reactive protein (CRP) is a major acute phase protein in both people and dogs. OBJECTIVE: The objective of this study was to evaluate the precision and accuracy of 3 different point-of-care tests (POCT) for canine CRP (cCRP) in comparison to a standard ELISA test, and to assess storage stability. MATERIAL AND METHODS: Blood samples were collected from 125 dogs (23 healthy and 102 diseased). Serum cCRP measurements were performed using the TECOmedical AG, the EUROLyser Diagnostica, and the LifeAssays POCT. The TECOmedical AG ELISA validated for canine serum was used as a reference method. Statistical analyses included descriptive statistics, inter assay variance for each POCT, comparison of results from each POCT with the ELISA using Spearman's correlation and Bland-Altman plots, and a t-test to evaluate sample stability. RESULTS: ELISA cCRP values ranged from 0.1-4.7 mg/L (median 1.3) in healthy dogs and from 0-282 mg/L (median 17.3) in diseased dogs. Spearman's correlation coefficient between ELISA and the respective POCT measurements for cCRP concentration was 0.89 for TECOmedical, 0.85 for EUROLyser, and 0.97 for LifeAssays. Bias calculated from Bland-Altman difference plots was 27.6% for TECOmedical, -14.2% for EUROLyser, and -15.7% for LifeAssays. Inter assay reliability was > 0.9 for all POCT. Total observed error of the EUROLyser was 28.2% and therefore met the acceptable total error of 29.6%. CONCLUSIONS: All POCTs were able to measure cCRP, but precision, accuracy, and correlation coefficients varied among the 3 systems. Therefore, serial measurements for monitoring of cCRP in dogs should always be performed using the same POCT system.