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Objective: Acidosis decreases myocardial contractile and myofibrillar responsiveness by reducing the calcium sensitivity of contractile proteins, which could reduce the effectiveness of pimobendan. We aimed to assess the cardiovascular effects of pimobendan in dogs subjected to acute respiratory acidosis. Design: Randomized crossover study with a 2‐week washout period. Setting: University Laboratory. Animals: Six healthy research Beagle dogs. Interventions: Anesthetized dogs were administered 2 doses of IV pimobendan during conditions of eucapnia (Paco2 35–40 mm Hg) and hypercapnia (Paco2 90–110 mm Hg). Eucapnia was maintained by positive pressure ventilation and hypercapnia was induced by adding exogenous CO2 to the anesthesia circuit. Heart rate (HR), systemic arterial blood pressure, cardiac output (CO), systemic and pulmonary vascular resistance (SVR and PVR, respectively), and pulmonary arterial pressure (PAP) were measured at baseline and 60 min after administering 0.125 mg/kg (low) and 0.25 mg/kg (high) pimobendan intravenously. Blood gas and biochemical analyses were performed at baseline and at the end of the experiment. Measurements and Main Results: The median baseline blood pH was 7.41 (range: 7.33–7.45) and 7.03 (range: 6.98–7.09) under conditions of eucapnia and hypercapnia, respectively. The serum concentrations of epinephrine and norepinephrine and the HR, CO, and PAP were higher, and SVR was lower at baseline in hypercapnic dogs. Pimobendan dose‐dependently increased CO in eucapnia (baseline: 3.6 ± 0.2 L/kg/m2 [mean ± SE], low: 5.0 ± 0.4 L/kg/m2, high: 5.8 ± 0.5 L/kg/m2, P < 0.001) and hypercapnia (baseline: 4.9 ± 0.5 L/kg/m2, low: 5.8 ± 0.5 L/kg/m2, high: 6.2 ± 0.5 L/kg/m2, P < 0.001), and increased HR and decreased SVR and PVR under both conditions (P < 0.001). In hypercapnia, the degree of increase or decrease of these cardiovascular measurements (except for PAP) by pimobendan was less than that in the eucapnic dogs. Conclusions: Pimobendan maintains function as an inodilator in anesthetized dogs with induced respiratory acidosis. [ABSTRACT FROM AUTHOR]

Increased intracranial pressure (ICP) can cause irreversible pathological changes in the canine brain and can be life‐threatening, so prompt diagnosis and therapeutic responses are warranted. The purposes of this prospective experimental study were to evaluate phase‐contrast MRI (PC‐MRI) as a non‐invasive method for quantifying cerebrospinal fluid (CSF) and basilar artery flow, and to assess effects of intravenous administration of hypertonic fluid. A PC‐MRI scan was acquired for six healthy Beagle dogs at the level of the mesencephalic aqueduct. Either 1.0 g/kg mannitol or isotonic saline solution was administered intravenously for 15 min each at a matched dose volume of 5 mL/kg. Basilar artery and CSF flow rates were measured and their values compared between mannitol and isotonic saline solution groups before administration, and subsequently every 15 min for 2 h post‐administration. The CSF dynamics were further assessed by measuring repeat flow from the caudal to rostral direction and the rostral to caudal direction as the number of waves. No significant difference was observed in basilar or and CSF flow velocity between the two groups (P >.05). However, administration of isotonic saline solution tended to increase basilar artery velocity slightly over time, while CSF velocity remained unchanged. In the mannitol group, CSF wave forms tended to be reduced at 60 and 75 min (P >.05). Findings from this preliminary study indicated that it is feasible to measure the dynamics of CSF and basilar artery flow by PC‐MRI, but no flow differences could be detected for mannitol versus isotonic saline administration. [ABSTRACT FROM AUTHOR]

Thus far, there are few computed tomography (CT) characteristics that can distinguish benign and malignant etiologies. The criteria are complex, subjective, and difficult to use in clinical applications due to the high level of experience needed. This study aimed to identify practical CT variables and their clinical relevance for broadly classifying histopathological diagnoses as benign or malignant. In this prospective study, all dogs with liver nodules or masses that underwent CT examination and subsequent histopathological diagnosis were included. Signalments, CT findings and histopathological diagnoses were recorded. Seventy liver nodules or masses in 57 dogs were diagnosed, comprising 18 benign and 52 malignant lesions. Twenty-three qualitative and quantitative CT variables were evaluated using univariate and stepwise multivariate analyses, respectively. Two variables, namely, the postcontrast enhancement pattern of the lesion in the delayed phase (heterogeneous; odds ratio (OR): 14.7, 95% confidence interval (CI): 0.82-262.03, P=0.0429) and the maximal transverse diameter of the lesion (>4.5 cm; OR: 33.3, 95% CI: 2.29-484.18, P=0.0006), were significantly related to the differentiation of benign from malignant liver lesions, with an area under the curve of 0.8910, representing an accuracy of 88.6%. These findings indicate that features from triple-phase CT can provide information for distinguishing pathological varieties of focal liver lesions and for clinical decision making. Evaluations of the maximal transverse diameter and postcontrast enhancement pattern of the lesion included simple CT features for predicting liver malignancy with high accuracy in clinical settings. [ABSTRACT FROM AUTHOR]

In human bladder cancer patients, ultrasonography is extensively used not only to identify tumor masses but also to evaluate tumor size, shape, echogenicity, location, and degree of tumor invasion into the bladder wall. The information revealed by ultrasonography delineates the tumor's biological features and facilitates prediction of prognosis. However, in veterinary medicine the feasibility of using ultrasonography for these purposes has not been fully investigated. In this retrospective study, we reviewed cases of dogs with histologically confirmed bladder mass lesions, including transitional cell carcinoma ( n = 22) and polypoid cystitis ( n = 5), to determine whether ultrasonography could reliably predict bladder wall involvement. By following patients with transitional cell carcinoma until death, we also determined whether ultrasonographic tumor size, shape, echogenicity, and mass location were related to prognosis. Wall involvement as revealed by ultrasound was significantly ( P = 0.00005) associated with histological muscular layer involvement with a sensitivity of 93% (95% Confidence interval, 79-98%) and specificity of 92% (95% Confidence interval, 76-98%). Ultrasonographic wall involvement ( P = 0.03, vs. noninvolvement), heterogeneous mass ( P = 0.02, vs. homogeneous mass), and trigone location ( P = 0.01, vs. other locations) characteristics were significantly associated with shorter survival times in transitional cell carcinoma cases. Findings indicated that ultrasonographic characteristics such as wall involvement, heterogeneous mass, and trigone location could be reliable prognostic indicators in canine transitional cell carcinoma. [ABSTRACT FROM AUTHOR]

Haemangiosarcoma (HSA) is an important malignant neoplasm of dogs that originates from vascular endothelial cells. This study explored the suitability of using serum big endothelin-1 (ET-1) as a tumour marker for canine spontaneous HSA. Serum big ET-1 was measured in dogs with splenic HSA ( n  = 14), splenic malignant tumours other than HSA ( n  = 10), benign splenic lesions ( n  = 11) and normal healthy dogs ( n  = 17) by ELISA. Serum big ET-1 levels in dogs with HSA were significantly ( P  < 0.01) higher than in other dogs. High sensitivity (100%, 95% confidence interval 86–100%) and specificity (95%, 95% confidence interval 86–95%) for HSA diagnosis were obtained using a cut-off of 17 pg/mL according to receiver operating characteristic (ROC) curves (area under ROC curve 0.93). PPET1 , ETA, VEGF and Hif1-α mRNA expression, measured by real-time PCR, were elevated in HSA compared with normal tissues. These findings suggest that elevated serum big ET-1 could be used as a diagnostic marker for canine HSA. [ABSTRACT FROM AUTHOR]