Background: Feline hyperthyroidism is the most prevalent endocrine disorder of older cats; TT4 monitoring is costly and often inaccessible. Methods: Forty-three cats with primary hyperthyroidism were followed prospectively at baseline (T0) and at 1, 3 and 6 months (T1, T2, T3). Hct, Hgb, MCV, ALT and TT4 were measured at each visit. Per-timepoint correlations, repeated-measures correlation (rmcorr), linear mixed-effects models, and Friedman and ROC analyses were performed. Results: TT4 correlated with Hct (r = 0.875 at T1 to 0.943 at T3), MCV (0.907 to 0.964), Hgb (0.836 to 0.946) and ALT (0.919 to 0.981), intensifying progressively. Within individual cats, Hct (rmcorr r = 0.873) and MCV (rmcorr r = 0.881) tracked TT4, and for Hct, the within-cat coefficient exceeded the between-cat coefficient. All primary parameters and ALT changed significantly from T0 to T1 (all p < 0.001). ROC analysis identified Hct ≥ 35.2% at T2 as the optimal cut-off (AUC = 0.972, 95% CI 0.914–1.000; sensitivity 96.7%, specificity 92.3%). Conclusions: Hct and MCV tracked TT4 within individual cats during methimazole therapy and returned toward pre-treatment values after discontinuation. A rising Hct or MCV in a treated cat may signal loss of therapeutic control and prompt TT4 re-evaluation, without replacing hormonal monitoring.

The Sequential Organ Failure Assessment (SOFA) score grades dysfunction in six components in people, using thresholds fixed against human reference ranges and a human case mix. Whether those numbers transfer to cats has not been examined. Of 52 cats assessed for eligibility, 23 met predefined systemic inflammatory response syndrome criteria, 22 of them non-septic, and an adapted score was calculated at admission from non-invasive measurements and one venous sample. A complete score was obtained in every cat. Under the applied bilirubin thresholds, the hepatic sub-score exceeded zero in 21 of 23 cats and, with the renal component, accounted for 63.0% of the mean total score; removing that component lowered the median total from 6.0 to 3.0 and left three cats scoring zero. Under stated physiological assumptions, translating the original PaO₂/FiO₂ thresholds through the feline oxyhaemoglobin dissociation curve placed the first respiratory threshold near 91%, rather than the 95% applied here, and removed the respiratory point from six cats. Five of the 23 cats did not survive to discharge, too few for any outcome analysis, and none was attempted. The framework was measurable in this setting, but its thresholds describe admission abnormalities rather than organ dysfunction and require feline-specific calibration.

Serum creatinine (sCr), blood urea nitrogen (BUN) and symmetric dimethylarginine (SDMA) reflect glomerular filtration only and are subject to non-renal confounders including lean body mass, limiting early detection of renal dysfunction in geriatric dogs. We evaluated serum cystatin C (sCysC) and the urinary N-acetyl-β-D-glucosaminidase-to-creatinine ratio (NAG index) as early renal markers in healthy geriatric dogs. Sixty-one neutered geriatric dogs, free of clinical disease and of extrarenal laboratory abnormalities, were stratified into three groups: controls (n = 36), subclinical (normal sCr, ≥1 elevated biomarker; n = 17) and azotaemic chronic kidney disease (CKD; sCr > 1.5 mg/dL; n = 8). sCysC was measured by a canine-specific ELISA and the NAG index by colorimetric assay. Of the 61 dogs, 17 (27.9%) had at least one elevated biomarker with normal sCr, and all 17 also had normal BUN, indicating pre-azotaemic changes identified predominantly by sCysC. The NAG index was elevated in 6/17 (35.3%) subclinical dogs and SDMA in none (0/17). Because sCysC status partly informed group allocation and no independent measure of glomerular filtration rate was obtained, these findings characterise an altered renal biochemical phenotype rather than establish diagnostic accuracy, and require prospective validation.

Background: The role of bacterial infection in canine extrahepatic biliary disease remains inconsistently characterized. This retrospective case series evaluated associations between ultrasonographic gallbladder findings and bile culture results in dogs. Materials and Methods: Sixty-seven dogs were screened between March 2024 and December 2025, of which 49 met inclusion criteria (clinical, biochemical, and ultrasonographic evidence of gallbladder disease) and underwent bile sampling by ultrasound-guided cholecystocentesis (n = 45) or intraoperative collection (n = 4). Samples were cultured aerobically and anaerobically; isolates identified by MALDI-TOF MS were further tested for in vitro antimicrobial susceptibility using Kirby–Bauer disk diffusion method. Results: Among the 49 included dogs, ultrasonography identified cholecystitis (75.5%), cholelithiasis (16.3%), and biliary mucocele (8.2%). Bile cultures were positive in 43/49 dogs (87.8%), yielding only aerobic bacteria. Escherichia coli (46.5%) and coagulase-positive Staphylococci (30.2%) were most frequently isolated organisms. However, these findings should be interpreted cautiously due to small subgroup sizes and the exploratory nature of the analysis. Conclusions: In this selected referral population, bacterial isolates were frequently recovered from bile samples, particularly in dogs with cholecystitis. Prospective studies involving larger populations are warranted to confirm these results, define the bacterial prevalence and clinical significance of bacterial colonization or infection, and further refine evidence-based diagnostic and treatment strategies for dogs with extrahepatic biliary disease.

Background: Ultrasound-guided kidney biopsy is an essential diagnostics method that can increase the accuracy of the differential diagnosis between acute and chronic nephropathies. In addition, it will help clinicians perform an etiologic diagnosis, issue a prognosis, and orient therapy for the majority of parenchymal nephropathies. Due to the relative invasiveness and potential adverse effects, the use of kidney biopsies is limited among practitioners. Results: Twenty-eight dogs, of mixed breed and variable ages, of which 11 (39, 29%) were males and 17 (60, 71%) were females, were examined and underwent an ultrasound-guided kidney biopsy to establish a definitive diagnosis. The patients were presented with a variety of diffuse nephropathies, such as kidney lymphoma: 1 (3.57%), glomerulonephritis: 13 (46.43%), tubulointerstitial nephritis: 11 (39.29%), and nephrocalcinosis. A total of 3 (10.71%) of 18 (64.29%) were in acute kidney injury, and 10 (35.71%) were CKD patients. The type and the severity of the kidney lesions were correlated with changes in the urinary n-acetyl-beta-d-glucosaminidase index (iNAG. To quantify the side effects of percutaneous kidney biopsy, the magnitude of post-biopsy hematuria and changes in urinary iNAG activity were evaluated. The results indicate a significant post-biopsy increase in the urinary iNAG activity in all the patients that underwent this procedure (100.08 ± 34.45 U/g), with a pre-biopsy iNAG vs. 147.65 ± 33.26 U/g post-biopsy iNAG (p < 0.001), suggesting an intensification in the kidney tubular damage that comes consecutives to kidney puncture and sampling. Transitory macro- or microhematuria were constant findings in all the dogs that underwent ultrasound-guided kidney biopsy, but the magnitude and extent could not be associated with the platelet count (PLT 109/L), aPTT (s), and PT (s) levels in our patients, and they were also resolved after 12–24 h without therapeutic interventions. Conclusions: Ultrasound-guided renal biopsy was shown to be a minimally invasive diagnostic procedure that causes transient and limited effects on kidney structures. Although these effects were minor and resolved without intervention, we feel that the benefit of obtaining higher-quality biopsied tissue outweighs the higher risks associated with this procedure.