OBJECTIVE To evaluate the clinicopathologic, hemodynamic, and echocardiographic effects of short-term administration of anti-inflammatory dosages of prednisolone to systemically normal cats. ANIMALS 10 cats with allergic dermatitis and 10 healthy control cats. PROCEDURES Cats with allergic dermatitis were randomly allocated to 2 groups and received 2 dosages of prednisolone (1 and 2 mg/kg/d, PO, for 7 days) in a crossover design followed by 9-day tapering and 14-day washout periods. Each prednisolone-treated cat was matched to a healthy control cat on the basis of sex, neuter status, age (± 1 year), and body weight (± 10%). Control cats received no treatment during the 35-day observation period. Clinicopathologic, echocardiographic, and hemodynamic variables were measured at baseline (day 0) and predetermined times during and after prednisolone administration and compared within and between the 2 treatment groups. RESULTS Prednisolone-treated cats had expected clinicopathologic alterations (mild increases in neutrophil and monocyte counts and serum concentrations of albumin, cholesterol, and triglycerides) but systolic arterial blood pressure; blood glucose, serum potassium, and cardiac biomarker concentrations; urinary sodium excretion; and echocardiographic variables did not differ significantly from baseline at any time. Statistically significant, albeit clinically irrelevant, increases in blood glucose and N-terminal pro-B-type natriuretic peptide concentrations were observed between baseline and the prednisolone pharmacokinetic steady state (7 days after initiation) only when the 2-mg/kg dosage was administered. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated short-term oral administration of anti-inflammatory dosages of prednisolone did not cause relevant hemodynamic, echocardiographic, or diabetogenic effects in systemically normal cats with allergic dermatitis.

OBJECTIVE To comprehensively characterize cardiac structure and function, from infancy to adulthood, in male and female wild-born captive chimpanzees (Pan troglodytes) living in sanctuaries. ANIMALS 290 wild-born captive chimpanzees. PROCEDURES Physical and echocardiographic examinations were performed on anesthetized chimpanzees in 3 sanctuaries in Africa between October 2013 and May 2017. Results were evaluated across age groups and between sexes, and potential differences were assessed with multiple 1-way independent Kruskal-Wallis tests. RESULTS Results indicated that left ventricular diastolic and systolic function declined at a younger age in males than in females. Although differences in right ventricular diastolic function were not identified among age groups, right ventricular systolic function was lower in adult chimpanzees (> 12 years old), compared with subadult (8 to 12 years old) and juvenile (5 to 7 years old) chimpanzees. In addition, male subadult and adult chimpanzees had larger cardiac wall dimensions and chamber volumes than did their female counterparts. CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study provided useful reference intervals for cardiac structure and function in captive chimpanzees categorized on the basis of age and sex; however, further research is warranted to examine isolated and combined impacts of blood pressure, age, body weight, and anesthetic agents on cardiac structure and function in chimpanzees.

OBJECTIVE To determine the relationship between acute volume overload and echocardiographic indices of right ventricular (RV) function and dyssynchrony in healthy dogs. ANIMALS 7 healthy Beagles. PROCEDURES Right heart catheterization and echocardiography were performed in 7 healthy anesthetized Beagles at baseline and after induction of volume overload. Volume overload was induced by IV infusion of lactated Ringer solution (150 mL/kg/h for 90 minutes). Echocardiographic indices of RV function, including peak velocity of systolic tricuspid annular motion, tricuspid annulus plane systolic excursion, fractional area change, RV Tei index, RV longitudinal strain (RVLS), and systolic RV longitudinal strain rate (RVLSR), were obtained by use of speckle tracking echocardiography (STE). In addition, SD of the systolic shortening time of the right ventricle for the 6 segments (RV-SD6) was determined with STE. RESULTS Volume overload significantly increased the RV end-diastolic pressure, compared with the baseline value. Echocardiographic indices of RV function, except for septal RVLSR, were significantly enhanced by volume overload. In contrast, RV-SD6 did not change with volume overload. Although echocardiographic indices of RV function, except for septal RVLSR, were correlated with RV end-diastolic pressure, RV-SD6 was not correlated. CONCLUSIONS AND CLINICAL RELEVANCE Echocardiographic indices of RV function, including RVLS and RVLSR, were affected by acute short-term volume overload. Therefore, results for assessment of RV function by use of STE in dogs with clinical conditions associated with right-sided chronic volume overload, such as tricuspid and pulmonic regurgitation, should be interpreted with caution.

OBJECTIVE To determine variability of global longitudinal strain (GLS) and strain rate (SR) measurements in dogs with and without cardiac disease derived from 2-D speckle tracking echocardiography (STE) by use of various software. ANIMALS 2 cohorts comprising 44 dogs (23 cardiovascularly healthy and 21 with cardiac disease) and 40 dogs (18 cardiovascularly healthy and 22 with cardiac disease). PROCEDURES Transthoracic echocardiographic images in each cohort were analyzed with vendor-independent software and vendor-specific 2-D STE software for each of 2 vendors. Values for GLS and SR obtained from the same left parasternal apical views with various software were compared. Intraobserver and interobserver variability was determined, and agreement among results for the various software was assessed. RESULTS Strain analysis was not feasible with vendor-independent software for 20% of images obtained with the ultrasonography system of vendor 1. Intraobserver and interobserver coefficient of variation was < 10% for GLS values, whereas SR measurements had higher variance. There was a significant difference in GLS and SR obtained for each cohort with different software. Evaluation of Bland-Altman plots revealed wide limits of agreement, with variance for GLS of up to 6.3 units in a single dog. CONCLUSIONS AND CLINICAL RELEVANCE Results of longitudinal strain analysis were not uniform among software, and GLS was the most reproducible measurement. Significant variability in results among software warrants caution when referring to reference ranges or comparing serial measurements in the same patient because changes of < 6.5% in GLS might be within measurement error for different postprocessing software.

OBJECTIVE To compare the effects of a dexmedetomidine-ketamine-midazolam (DKM) anesthetic protocol versus isoflurane inhalation anesthesia on echocardiographic variables and plasma cardiac troponin 1 (cTnI) concentration in black-tailed prairie dogs (BTPDs; Cynomys ludovicianus). ANIMALS Nine 6-month-old sexually intact male captive BTPDs. PROCEDURES Each BTPD was randomly assigned to be anesthetized by IM administration of dexmedetomidine (0.25 mg/kg), ketamine (40 mg/kg), and midazolam (1.5 mg/kg) or via inhalation of isoflurane and oxygen. Three days later, each BTPD underwent the alternative anesthetic protocol. Echocardiographic data and a blood sample were collected within 5 minutes after initiation and just prior to cessation of each 45-minute-long anesthetic episode. RESULTS Time or anesthetic protocol had no significant effect on echocardiographic variables. For either protocol, plasma cTnI concentration did not differ with time. When administered as the first treatment, neither anesthetic protocol significantly affected plasma cTnI concentration. However, with regard to findings for the second treatments, plasma cTnI concentrations in isoflurane-treated BTPDs (n = 4; data for 1 animal were not analyzed because of procedural problems) were higher than values in DKM-treated BTPDs (4), which was suspected to be a carryover effect from prior DKM treatment. CONCLUSIONS AND CLINICAL RELEVANCE The DKM and isoflurane anesthetic protocols did not have any significant effect on echocardiographic measurements in the BTPDs. Increases in plasma cTnI concentration during the second anesthetic episode were evident when BTPDs underwent the DKM anesthetic protocol as the first of the 2 treatments, suggestive of potential myocardial injury associated with that anesthetic protocol. Clinicians should consider these findings, especially when evaluating BTPDs with known or suspected cardiac disease.

OBJECTIVE To evaluate the diagnostic usefulness of focused cardiac ultrasonography and selected echocardiographic variables for predicting fluid responsiveness in conscious, spontaneously breathing dogs with various clinical conditions. ANIMALS 26 dogs (15 males and 11 females) with a median age of 84 months (range, 12 to 360 months) and median body weight of 8 kg (range, 2 to 35 kg) referred for various clinical conditions. PROCEDURES Left ventricular end-diastolic internal diameter normalized to body weight (LVIDDn), left ventricular volume score (LVVS), left ventricular end-diastolic volume index (EDVI), aortic velocity time integral (VTIAo), and aortic peak flow velocity (VmaxAo) were echocardiographically measured before and after IV administration of a bolus of lactated Ringer solution (4 mL/kg) over a 1-minute period. Dogs were classified on the basis of the observed change in aortic stroke volume following fluid administration as responders (≥ 15%) or nonresponders (< 15%) to fluid administration. Receiver operating characteristic curves were generated for the ability of LVVS, LVIDDn, EDVI, VTIAo, and VmaxAo to predict responder status. RESULTS 13 dogs were classified as responders and 13 as nonresponders. Areas under the receiver operating characteristic curves (95% confidence intervals) for predicting fluid responsiveness were as follows: VTIAo, 0.91 (0.74 to 0.99); LVIDDn, 0.85 (0.66 to 0.96); EDVI, 0.85 (0.65 to 0.96); LVVS, 0.85 (0.65 to 0.96); and VmaxAo, 0.75 (0.54 to 0.90). CONCLUSIONS AND CLINICAL RELEVANCE The evaluated echocardiographic variables were useful for noninvasive prediction of fluid responsiveness in conscious dogs and could be valuable for informing clinical decisions regarding fluid therapy.