BackgroundDegenerative mitral valve disease is a common heart problem in dogs. The aims are to evaluate the relationships between right and left ventricular function, and blood lactate concentrations, assess prognostic contribution, and investigate whether serum peptidomics profile could reveal markers or determine the stage in dogs with valve degeneration.Materials and MethodsNinety-three dogs were evaluated in this study. Thirty-nine dogs' serum was collected and analyzed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. The Kaplan–Meier curve was used to predict the outcomes of mitral valve disease. Follow-up was obtained by a questionnaire or telephone to determine a survival time.ResultsThe BUN/creatinine ratio, vertebral heart score, and left atrium/aorta ratio were the independent predictors of cardiac mortality. Right ventricular systolic dysfunction was found in 50% of dogs with mitral valve disease. Dogs with right ventricular dysfunction had a significantly higher incidence of lower fractional shortening and larger right ventricular dimensions. The occurrence of right-sided dysfunction is proportionate to age and the degree of left ventricular dysfunction. High blood lactate concentrations were investigated in dogs with mitral valve disease stage C compared with stage B. The peptides such as mitogen-activated protein kinase, kallikrein, and tenascin-C appeared in the heart disease progression group.ConclusionRight-hearted function assessment, blood lactate levels, and peptidomics analysis may help early detection and prognosis of this disease in dogs. Peptidomics profiles from this study demonstrate the possibility for prognosis indicators of heart valve degeneration.

To date, the pharmacokinetics of fluoroquinolones in estuarine crocodiles (Crocodylus porosus) have been reported for enrofloxacin but not for marbofloxacin (MBF), which is a broad‐spectrum antibiotic used only in veterinary medicine. This study investigated the pharmacokinetics of MBF after intramuscular administration at two difference dosages (2 and 4 mg/kg body weight) in estuarine crocodiles and estimated pharmacokinetic/pharmacodynamic (PK/PD) surrogate parameters for the optimization of dosage regimens. Ten treated estuarine crocodiles were divided into two groups (n = 5) using a randomization procedure according to a parallel study design. Blood samples were collected at assigned times up to 168 h. MBF plasma samples were cleaned up using liquid–liquid extraction and analyzed using a validated high‐performance liquid chromatography method with fluorescence detection. A non‐compartment approach was used to fit the plasma concentration of MBF vs time curve for each crocodile. The plasma concentrations of MBF were quantifiable for up to 168 h in both groups. The elimination half‐life values of MBF were long (33.99 and 39.28 h for 2 and 4 mg/kg, respectively) with no significant differences between the groups. The average plasma protein binding of MBF was 30.85%. According to the surrogated PK/PD parameter (AUC0–24‐to‐MIC ratio >100–125), the 2 and 4 mg/kg dosing rates should be effective for bacteria with MIC values lower than 0.125 μg/mL and 0.35 μg/mL, respectively.