Clinical relevance of serum electrolytes in dogs and cats with acute heart failure : a retrospective study

Background: Hypochloremia is a strong negative prognostic factor in humans with congestive heart failure (CHF), but the implications of electrolyte abnormalities in small animals with acute CHF are unclear. Objectives: To document electrolyte abnormalities present upon admission of small animals with acute CHF, and to assess the relationship between electrolyte concentrations and diuretic dose, duration of hospitalization and survival time. Animals: Forty-six dogs and 34 cats with first onset of acute CHF. Methods: Retrospective study. The associations between electrolyte concentrations and diuretic doses were evaluated with Spearman rank correlation coefficients. Relationship with duration of hospitalization and survival were assessed by simple linear regression and Cox proportional hazard regression, respectively. Results: The most commonly encountered electrolyte anomaly was hypochloremia observed in 24% (9/46 dogs and 10/34 cats) of cases. In dogs only, a significant negative correlation was identified between serum chloride concentrations at admission (median 113 mmol/L [97-125]) and furosemide doses both at discharge (median 5.2 mg/kg/day [1.72-9.57]; r = 0.59; P < .001) and at end-stage heart failure (median 4.7 mg/kg/day [2.02-7.28]; r = 0.62; P = .005). No significant hazard ratios were found for duration of hospitalization nor survival time for any of the electrolyte concentrations. Conclusions and Clinical Importance: The observed association between serum chloride concentrations and diuretic doses suggests that hypochloremia could serve as a marker of disease severity and therapeutic response in dogs with acute CHF

Loop diuretic therapy for congestive heart failure in dogs and cats : what are we missing?

Congestive heart failure (CHF) is a complex clinical syndrome affecting both people and small animals, is characterized by severe clinical signs (e.g. dyspnea, cough, exercise intolerance) and is associated with high morbidity and mortality. Currently, the loop diuretic furosemide is the cornerstone of CHF treatment because it reduces fluid congestion, and thus alleviates the clinical signs. However, response to this diuretic can vary greatly among humans, and progressive increase in dose to maintain the same level of diuresis can be necessary in some cases, a concept known as diuretic resistance in people. Consequently, the need to switch from furosemide to alternative diuretics has been suggested. Another loop diuretic torasemide was found to provide lower mortality and hospital readmission rates compared to furosemide. Few studies have outlined benefits of the use of torasemide in dogs, but little is known about its pharmacological properties and clinical implications in cats. Additionally, diuretic resistance is also suspected to occur dogs and cats, but reports are scarce and no diagnostic technique has been fully validated to identify such a phenomenon

Pharmacokinetic and pharmacodynamic properties of orally administered torasemide in healthy cats

Background In people and dogs, torasemide has higher bioavailability, longer half-life, and longer duration of action than equivalent doses of furosemide but data regarding pharmacological properties of torasemide in cats are limited. Objective To assess pharmacokinetic and pharmacodynamic parameters of torasemide in healthy cats, and to investigate the effects of a single administration of torasemide on indicators of diuresis, plasma creatinine concentration, blood pressure, electrolyte concentrations and markers of the renin-angiotensin-aldosterone system (RAAS). Animals Six clinically healthy adult European shorthair cats. Methods Randomized 4-period crossover design with 3 groups and 4 treatments. Pharmacokinetic parameters were obtained using a noncompartmental analysis, and the clinically effective dose was assessed using a Hill model. Results Mean absolute bioavailability was estimated at 88.1%. Mean total body clearance was 3.64 mL/h/kg and mean terminal half-life was 12.9 hours. Urine output significantly increased after torasemide administration (P < .001). The urine sodium : potassium ratio (uNa : uK) paralleled and was statistically correlated to urine output (P < .001). Administration of a single torasemide dose led to a significant dose-dependent increase in urine aldosterone : creatinine ratio (uAldo : C; P < .001) and a transient decrease in plasma potassium concentration (P < .001) but did not affect blood pressure or plasma creatinine concentration. Conclusions and Clinical Importance A single torasemide dose leads to a significant increase in diuresis and renin-angiotensin-aldosterone system (RAAS) activation in healthy cats, with high absolute bioavailability, and without clinically relevant adverse effects. Pharmacokinetic parameters indicate that once daily dosing of 0.27 mg/kg may be appropriate in a clinical setting