Roberto Rabozzi

Objective: To assess the role of CT in detecting canine renal neoplasms and describe their imaging features. Methods: 32 dogs with histologically and cytologically confirmed renal tumors were included. Computed tomography scans were reviewed for qualitative parameters: lesions number, size, margins, enhancement pattern, mineralization, laterality, intrarenal location, hemorrhage, lymphadenopathy, pulmonary metastases and collateral vessels. Quantitative parameters included lesion diameter and pre- and postcontrast attenuation. Data distribution was tested with the Shapiro-Wilk test, and intergroup differences were evaluated using the Fisher exact test. Results: Diagnoses comprised primary renal tumors—renal cell carcinoma (RCC; 12 of 32), sarcoma (2 of 32), hemangiosarcoma (1 of 32), primary lymphoma (1 of 32), and cystic adenoma (1 of 32)—as well as multicentric lymphoma (ML; 5 of 32) and metastatic lesions (10 of 32). Primary tumors were mainly unilateral masses, whereas ML and metastases appeared as bilateral nodules. Collateral vessels were significantly more frequent in RCC than in ML or metastases and were also associated with mass lesions rather than nodular lesions. Multicentric lymphoma showed more homogeneous postcontrast enhancement than primary tumors. Conclusions: CT provides key information to differentiate canine renal tumor types. Collateral vessels may indicate RCC and are more prevalent in mass lesions; therefore, they should be considered in surgical planning. Canine lymphoma showed CT features consistent with human reports, although overlap among tumor subtypes reduced specificity. Clinical Relevance: This study describes novel tomographic features of canine renal neoplasia and comprehensively summarizes their CT characteristics, aiding diagnosis and treatment planning.

Objective: To evaluate the relationship between the lung ultrasound score (LUSS) and oxygenation indices. Design: Retrospective study from January 2022 to December 2023. Setting: Private veterinary center. Animals: A total of 56 examinations from 42 dogs were used for the analysis. Interventions: None. Measurements and Main Results: Arterial blood gas analysis was performed on room air. By summing the score assigned to eight quadrants, a LUSS was created that ranged from 0/24 for fully aerated lungs to 24/24 for nonaerated lungs. Represented conditions included pneumonia ( n = 25), cardiogenic pulmonary edema (CPE; 14), pulmonary hypertension (6), systemic or extrathoracic diseases (5), lung contusion (3), and pulmonary thromboembolism (3). The LUSS had a moderate correlation with oxygenation indices, showing a negative relationship with the ratio between arterial partial pressure of oxygen and fraction of inspired oxygen (PaO ₂ :FiO ₂ ): r = −0.79 (95% confidence interval [CI]: −0.87 to −0.662; p < 0.001) and a positive relationship with the alveolar‐arterial gradient (Grad(A‐a)O ₂ ): r = 0.68 (95% CI: 0.502–0.797; p < 0.001). In pneumonia, this correlation was moderate with an r of −0.61 (95% CI: −0.809 to −0.28; p = 0.001), while in CPE, it was very strong, with r = −0.81 (95% CI: −0.938 to −0.49; p < 0.001). The relationship between the LUSS and the Grad(A‐a)O ₂ was weaker, with r = 0.48 (95% CI: 0.111–0.738; p = 0.014) for pneumonia and 0.6 (95% CI: 0.105–0.858; p = 0.023) for CPE. The correlation between the PaO ₂ /FiO ₂ ratio and the Grad(A‐a)O ₂ was very strong, with r = −0.89 (95% CI: −0.934 to −0.817; p < 0.001). Conclusions: This study found a strong correlation between the LUSS and pulmonary oxygenation indices, suggesting that the LUSS is an effective tool for stratifying the severity of lung aeration loss and investigating respiratory status in healthy dogs as well as those with respiratory failure.

Background: Metabolic acidosis is a common acid–base disorder in critically ill dogs, with fluid therapy being a key but debated treatment. Sodium bicarbonate's risks have spurred interest in safer alternatives such as sodium lactate. Objectives: To compare the efficacy of a chloride-free, high strong ion difference solution (H-SID) to Ringer's lactate (RL) for treating metabolic acidosis, hypothesizing the superiority of the H-SID solution. Animals: Forty-six dogs with metabolic acidosis from two veterinary hospitals. Methods: Prospective randomized multicenter study. Dogs were randomly assigned to receive either RL or H-SID at infusion rates of 4 or 10 mL/kg/h for 4 h, based on their volume status. H-SID was compounded with sodium (145 mmol/L), lactate (145 mmol/L), potassium (10 mmol/L), and aspartate (10 mmol/L) in sterile water for injection. Results: The H-SID group showed a significant increase in BE-ecf (mmol/L) at infusion rates of 4 mL/kg/h (p < 0.001) and 10 mL/kg/h (p < 0.001) when compared to the RL group. At the lower infusion rate, the median increase was 4.1 mmol/L (95% CI: 3.37, 6.71), whereas the RL group exhibited a variation of −0.1 (95% CI: −0.75, 2.2). At the higher infusion rate, the median increase was 11 mmol/L (95% CI: 8.16, 12.52) compared to the RL group variation of 1.3 (95% CI: 0.01, 2.96). Conclusions and Clinical Importance: Our results indicate a significant alkalizing effect of the H-SID solution in dogs with non-lactic metabolic acidosis, demonstrating a superior effect compared to the RL solution without notable adverse effects.

Background: Lung ultrasound (LUS) is a noninvasive tool for examining respiratory distress patients. The lung ultrasound score (LUSS) can be used to quantify and monitor lung aeration loss with good reliability. Hypothesis/Objectives: Assess the reliability of a new LUSS among raters with different levels of experience and determine how well the same raters agree on identifying patterns of LUS abnormalities. Animals: Forty LUS examinations of dogs and cats and 320 videos were reviewed from a digital database. Methods: Retrospective reliability study with post hoc analysis. Protocolized LUS were randomly selected; intrarater and interrater reliability of the LUSS and pattern recognition agreement among 4 raters with different levels of experience in LUS were tested. Results: The intrarater intraclass correlation coefficient (ICC) single measurement, absolute agreement, and 2-way mixed effects model was 0.967 for the high-experience rater (H-Exp), 0.963 and 0.952 for the medium-experience raters (M-Exp-1; M-Exp-2), and 0.950 for the low-experience rater (L-Exp). The interrater ICC average measurement, absolute agreement, and 2-way random effects model among the observers was 0.980. The Fleiss' kappa (k) values showed almost perfect agreement (k = 1) among raters in identifying pleural effusion and translobar tissue-like pattern, strong agreement for A-lines (k = 0.881) and B-lines (k = 0.806), moderate agreement (k = 0.693) for subpleural loss of aeration, and weak agreement (k = 0.474) for irregularities of the pleural line. Conclusions and Clinical Importance: Our results indicate excellent intra- and interrater reliability for LUS scoring and pattern identification, providing a foundation for the use of the LUSS in emergency medicine and intensive care.

Fluid responsiveness, defined as the response of stroke volume to fluid loading, is a tool to individualize fluid administration in order to avoid the deleterious effects of hypovolemia or hypervolemia in hospitalized patients. To evaluate the accuracy of two ultrasound indices, the caudal vena cava to abdominal aorta ratio (CVC/Ao) and the respiratory collapsibility of the caudal vena cava (cCVC), as independent predictors of fluid responsiveness in a heterogeneous population of spontaneously breathing, conscious, hospitalized dogs. A prospective, multicenter, observational, cross-sectional study was designed in twenty-five dogs. The accuracy of CVC/Ao and cCVC in predicting fluid responsiveness was evaluated by the area under the receiver operating characteristic curve (AUROC) in a group of hospitalized dogs after receiving a mini-fluid bolus of 4 mL/kg of Hartmann’s solution. Dogs with an increased aortic velocity time integral >15% were classified as fluid responders. Twenty-two dogs were finally included. Ten were classified as responders and 12 as non-responders. The AUROC curves were 0.88 for the CVC/Ao ratio (95% confidence interval, CI, 0.67–0.98; P=0.0001) and 0.54 for cCVC (95% CI 0.32–0.75; P=0.75). The CVC/Ao threshold optimized for best sensitivity (SE) and specificity (SP) values was 0.83 (SE 100%; SP 75%). In spontaneously breathing hospitalized dogs, the CVC/Ao measurement predicted stroke volume increase after a fluid bolus, while the respiratory variations in the cCVC did not discriminate between fluid responders and non-responders.

Propofol is one of the most widely used injectable anaesthetic agents in veterinary practice. Cardiovascular effects related to propofol use in dogs remain less well defined. The main objective of this study was to evaluate the haemodynamic changes during induction of general anaesthesia with propofol in healthy dogs, by a beat-to-beat continuous monitoring. All dogs were premedicated with intramuscular acepromazine (0.015 mg/kg) and methadone (0.15 mg/kg). Transthoracic echocardiography was used to measure the velocity time integral (VTI) of the left ventricular outflow tract. A syringe driver, programmed to deliver propofol 5 mg/kg over 30 s followed by a continuous infusion of 25 mg/kg/h, was used to induce and maintain anaesthesia. From the initiation of propofol administration, heart rate (HR) and mean invasive arterial blood pressure (MAP) were recorded every 5 s for 300 s, while aortic blood flow was continuously recorded and stored for 300 S. maximum cardiovascular depression was defined the lowest MAP (MAP_Tpeak) recorded during the monitored interval. VTI and VTI*HR were calculated at 0, 30, 90, 120, 150 and 300 s post administration of propofol, and at MAP_Tpeak. Haemodynamic effects of propofol in relation to plasma and biophase concentrations were also evaluated by pharmacokinetics simulation. The median (range) HR was significantly higher (p = 0.006) at the moment of maximum hemodynamic depression (Tpeak) [105(70–148) bpm] compared with pre-induction values (T0) [65(50–120) bpm]. The median (range) MAP was significantly lower (p < 0.001) at Tpeak [61(51–69) mmHg] compared with T0 [88(72–97) mmHg]. The median (range) VTI and VTI*HR were similar at the two time points [11.9(8.1–17.3) vs 13,3(9,4-16,5) cm, and 1172(806–1554) vs 1002(630–1159) cm*bpm, respectively]. Induction of anaesthesia with propofol causes a drop of arterial pressure in healthy dogs, however cardiac output is well maintained by compensatory chronotropic response. The magnitude of MAP_Tpeak may be strictly related with propofol plasma concentration.

OBJECTIVE To evaluate the correlation coefficient of the ratio between diameter of the caudal vena cava (CVC) and diameter of the aorta (Ao) in dogs as determined ultrasonographically with systolic pressure variation (SPV). ANIMALS 14 client-owned dogs (9 females and 5 males; mean ± SD age, 73 ± 40 months; mean body weight, 22 ± 7 kg) that underwent anesthesia for repair of skin wounds. PROCEDURES Anesthesia was induced. Controlled mechanical ventilation with a peak inspiratory pressure of 8 cm H₂O was immediately started, and SPV was measured. During a brief period of suspension of ventilation, CVC-to-Ao ratio was measured on a transverse right-lateral intercostal ultrasonographic image obtained at the level of the porta hepatis. When the SPV was ≥ 4 mm Hg, at least 1 bolus (3 to 4 mL/kg) of Hartmann solution was administered IV during a 1-minute period. Bolus administration was stopped and the CVC-to-Ao ratio measured when SPV was < 4 mm Hg. Correlation coefficient analysis was performed. RESULTS 28 measurements were obtained. The correlation coefficient was 0.86 (95% confidence interval, 0.72 to 0.93). Mean ± SD SPV and CVC-to-Ao ratio before bolus administration were 7 ± 2 mm Hg and 0.52 ± 0.16, respectively. Mean ± SD SPV and CVC-to-Ao ratio after bolus administration were 2 ± 0.6 mm Hg and 0.91 ± 0.13, respectively. CONCLUSIONS AND CLINICAL RELEVANCE In this study, the CVC-to-Ao ratio was a feasible, noninvasive ultrasonographically determined value that correlated well with SPV. (Am J Vet Res 2016;77:137–143)

The understanding of the cellular responses implicated in perinatal brain damages and the characterization of the various mechanisms involved might open new horizons for understanding the time of onset of a brain hypoxic-ischemic lesion and for effective therapeutic strategies.