Detection and genetic characterization of domestic cat hepadnavirus in cats with cavitary effusions.

After the identification of the novel domestic cat hepadnavirus (DCH) in 2018, its potential pathogenetic role in feline hepatic diseases has been suggested. Following the detection of DCH in a cat's serum and peritoneal effusion, the aim of this study was to retrospectively investigate the presence of DCH in cats with and without cavitary effusions along with DCH presence in effusions. Stored serum and effusion samples from cats with and without effusions admitted to the Veterinary Teaching Hospital of Lodi (Italy) in 2020-2022 were included based on results of hematobiochemical parameters. Effusions were classified based on cytological and physicochemical findings. The likelihood of liver damage was estimated based on clinical and laboratory findings. Samples were tested for DCH presence by quantitative PCR (qPCR). Positive samples were subjected to whole genome sequencing and phylogenetic analysis. DCH was detected in both serum and peritoneal effusion samples of 2/72 (2.8%) enrolled cats, included in the group with effusions (2/33; 6.1%), with one cat showing inflammatory and the other non-inflammatory effusion. Both DCH-positive cats belonged to the group with a likelihood of liver damage (2/22, 9.1%). Phylogeny showed that the DCH sequences from this study clustered with the prototypic Australian strain but were not included in the clade with other Italian DCH sequences. Results suggest the circulation of different DCH variants in Italy and show the presence of DCH in effusion samples from DCH-positive cats, mirroring the presence of HBV in body fluids from HBV-infected humans. Further studies are still recommended to define the pathogenic role of DCH in cats.

Lipoprotein profile of pleural and peritoneal transudates in dogs and cats.

BACKGROUND: Current diagnostic evaluation of transudative effusions rarely aids in identifying an underlying etiology. Lipoproteins in the fluid might reflect the site or nature of vessel involvement. OBJECTIVES: Improve the classification and diagnostic utility of pleural and peritoneal transudates in dogs and cats by investigating lipoprotein patterns in effusions. Compare these patterns with other peritonaeal and pleural fluid variables and underlying diseases. ANIMALS: Samples of transudates and serum from 18 cats and 37 dogs with transudative effusion (total nucleated cell count [TNCC] <5000 cells/µL) were analyzed. METHODS: Lipoprotein fractions, triglyceride, and cholesterol (CHO) concentrations were prospectively determined in paired fluid and serum samples. Standard fluid measurements were retrospectively collected. RESULTS: Two distinct fluid lipoprotein patterns were noted. Fluids rich in VLDL+IDL were associated with chronic kidney disease, acquired portosystemic shunts or protein-losing enteropathy (group I). Fluids rich in denser lipoproteins were associated with underlying heart disease, caudal vena cava syndrome or intracavitary neoplasia (group II). Group I and group II also had significant differences between fluid concentrations of CHO (x̄ = 8 vs 110 mg/dL) and TP (x̄ = 0.6 vs 3.8 g/dL), respectively. Five peritoneal transudates were triglyceride-rich (>100 mg/dL) and associated with pancreatitis. CONCLUSIONS AND CLINICAL IMPORTANCE: Protein-poor (TP <1.5 g/dL) and protein-rich (TP >2.5 g/dL) transudates were associated with distinct lipoprotein patterns and specific groups of disease. Effusions secondary to pancreatitis might be transudative and rich in triglycerides.

Laboratory diagnosis of canine uroperitoneum based on cellular and biochemical characteristics of serum and abdominal fluid.

BACKGROUND: Literature on the laboratory diagnosis of uroperitoneum is scarce, and it is mostly based on the biochemical findings of cavitary fluid and serum. Cell count and protein concentrations measurements are rarely used and available studies on this subject are based on a relatively small cohort of individuals. OBJECTIVES: We aimed to use a large sample pool of dogs to establish cutoff points for biochemical analytes in cavitary fluids and serum for the diagnosis of uroperitoneum. We also sought to evaluate the general classification of these cavitary fluids. METHODS: In a retrospective and prospective study, 180 canine abdominal effusion cases were evaluated, 30 of which were uroperitoneum (uroperitoneum group, UG) and 150 with other etiologies (non-uroperitoneum group, NUG). RESULTS: The results showed that 83.3% of UG and 12.7% of NUG abdominal fluid cases were not classified as transudates or exudates. The use of specific cutoffs for fluid creatinine concentrations (≥2.1 mg/dL) and fluid:serum creatinine ratios (Cf: Cs ≥ 1.25) in these unclassified effusions resulted in an accuracy of 99.0% for the laboratory diagnosis of uroperitoneum. CONCLUSIONS: The adoption of a new set of criteria and cutoffs based on the combination of parameters such as TP, TNCC, fluid creatinine and Cf: Cs improves the diagnosis of uroperitoneum in dogs.

Evaluation of a new multiple regression model based on biochemical parameters for the distinction of canine exudates and transudates.

BACKGROUND: The classification of effusions in human medicine currently uses biochemical parameters of verified analytical accuracy, while veterinary medicine is traditionally guided by protein content (TP) and total nucleated cell count (TNCC) in the effusion, without solid scientific support. OBJECTIVE: We aimed to assess the accuracy of the current veterinary classification system to distinguish transudates from exudates and create new tools involving biochemical parameters that better classify canine cavitary effusions. METHODS: Clinical, laboratory, and imaging data from 250 canine pleural and peritoneal effusions were retrospectively and prospectively collected, organized, and statistically evaluated. Multiple logistic regression analysis was performed using biochemical and cellular parameters. RESULTS: For identifying exudates, the accuracy (87.7%, n = 204) of the best traditional classification system (TNCC > 3000 cells/µL) was similar to that of the individual biochemical cutoff values with the greatest accuracy in the abdominal cavity (eg, cholesterol, CHO-E > 40.1 mg/dL, 87.3%, n = 55). The accuracy of albumin (ALB-E > 0.8 g/dL) in the pleural cavity was nonetheless higher (100%, n = 23). The best multiple predictive models for any cavity used the percentage of neutrophils and CHO-E (n = 72), presenting an accuracy, sensitivity, and specificity for the diagnosis of exudate of 88%, 96%, and 67%, respectively. CONCLUSIONS: Biochemical classification of pleural effusions has a higher accuracy than the traditional system (based on TP and TNCC). Utility and cutoff of analytes are different for each cavity. Implementing a multiple regression model or establishing ratios or gradients with concurrent serum values adds no significant improvement in the diagnostic potential of distinguishing transudate and exudates in dogs.