Short-Term Efficacy and Safety of Torasemide and Furosemide in 366 Dogs with Degenerative Mitral Valve Disease: The TEST Study

Comprehensive analysis of a widely pharmaceutical, furosemide, and its degradation products in aquatic systems: Occurrence, fate, and ecotoxicity

Many pharmaceutical compounds end up in the environment due to incomplete removal by wastewater treatment plants (WWTPs). Some compounds are sometimes present in significant concentrations and therefore represent a risk to the aquatic environment. Furosemide is one of the most widely used drugs in the world. Considered as an essential drug by the World Health Organization, this powerful loop diuretic is used extensively to treat hypertension, heart and kidney failure and many other purposes. However, this important consumption also results in a significant release of furosemide in wastewater and in the receiving environment where concentrations of a few hundred ng/L to several thousand have been found in the literature, making furosemide a compound of great concern. Also, during its transport in wastewater systems and WWTPs, furosemide can be degraded by various processes resulting in the production of more than 74 by-products. Furosemide may therefore present a significant risk to ecosystem health due not only to its direct cytotoxic, genotoxic and hepatotoxic effects in animals, but also indirectly through its transformation products, which are poorly characterized. Many articles classify furosemide as a priority pollutant according to its occurrence in the environment, its persistence, its elimination by WWTPs, its toxicity and ecotoxicity. Here, we present a state-of-the-art review of this emerging pollutant of interest, tracking it, from its consumption to its fate in the aquatic environment. Discussion points include the occurrence of furosemide in various matrices, the efficiency of many processes for the degradation of furosemide, the subsequent production of degradation products following these treatments, as well as their toxicity.

Self-Reported Utilization of International (ACVIM Consensus) Guidelines and the Latest Clinical Trial Results on the Treatment of Dogs with Various Stages of Myxomatous Mitral Valve Degeneration: A Survey among Veterinary Practitioners

BACKGROUND

Myxomatous mitral valve degeneration is the most common canine heart disease. Several clinical trials have investigated various treatments. The latest recommendations are published in the ACVIM consensus guidelines (2019). Our study aimed to investigate how closely veterinary practitioners apply the treatment recommendations of these guidelines and the latest clinical trials.

METHODS

An online survey was sent to Dutch and Belgian veterinary practices via digital channels.

RESULTS

The data from 363 fully completed surveys were analyzed. For stage B1 disease, 93% recommended, correctly, no treatment. For stage B2 disease, 67% of the respondents recommended starting pimobendan as monotherapy. For chronic treatment of stage C disease, 16 different drug combinations were mentioned, but nobody recommended surgery. Only 48% of the respondents recommended the only evidence-based drug combination: a loop diuretic with pimobendan. A concerning finding was the simultaneous prescription of two loop diuretics, by 19% of the respondents.

CONCLUSIONS

Treatment recommendations showed an increasing variation with more advanced disease stages from B1 through B2 to C. This reflects the increasing disagreement among the panelists who prepared the ACVIM consensus guidelines. Practitioners of our study seem to practice more evidence-based medicine than veterinary cardiologists, as it was reported in a recent survey-based study.

Diuretic resistance in patients with kidney disease: Challenges and opportunities

Edema caused by kidney disease is called renal edema. Edema is a common symptom of many human kidney diseases. Patients with renal edema often need to take diuretics.However, After taking diuretics, patients with kidney diseases are prone to kidney congestion, decreased renal perfusion, decreased diuretics secreted by renal tubules, neuroendocrine system abnormalities, abnormal ion transporter transport, drug interaction, electrolyte disorder, and hypoproteinemia, which lead to ineffective or weakened diuretic use and increase readmission rate and mortality. The main causes and coping strategies of diuretic resistance in patients with kidney diseases were described in detail in this report. The common causes of DR included poor diet (electrolyte disturbance and hypoproteinemia due to patients' failure to limit diet according to correct sodium, chlorine, potassium, and protein level) and poor drug compliance (the patient did not take adequate doses of diuretics. true resistance occurs only if the patient takes adequate doses of diuretics, but they are not effective), changes in pharmacokinetics and pharmacodynamics, electrolyte disorders, changes in renal adaptation, functional nephron reduction, and decreased renal blood flow. Common treatment measures include increasing in the diuretic dose and/or frequency, sequential nephron blockade,using new diuretics, ultrafiltration treatment, etc. In clinical work, measures should be taken to prevent or delay the occurrence and development of DR in patients with kidney diseases according to the actual situation of patients and the mechanism of various causes. Currently, there are many studies on DR in patients with heart diseases. Although the phenomenon of DR in patients with kidney diseases is common, there is a relatively little overview of the mechanism and treatment strategy of DR in patients with kidney diseases. Therefore, this paper hopes to show the information on DR in patients with kidney diseases to clinicians and researchers and broaden the research direction and ideas to a certain extent.

Retrospective evaluation of risk factors for development of kidney injury after parenteral furosemide treatment of left-sided congestive heart failure in dogs

BACKGROUND

Kidney injury (KI) has been documented in dogs treated with furosemide for left-sided congestive heart failure (CHF).

HYPOTHESIS/OBJECTIVES

Determine risk factors for development of KI in furosemide-treated dogs and determine the effect of KI on survival.

ANIMALS

Seventy-nine client-owned dogs receiving parenteral furosemide for CHF.

METHODS

Serum creatinine (sCr) and electrolyte concentrations were determined during hospitalization and at first outpatient reevaluation to detect and stage KI (increase in sCr ≥0.3 mg/dL). Furosemide dosage administered between timepoints was calculated. Multivariable modeling was performed to identify predictors of KI and percent change in serum biochemistry results over time.

RESULTS

Kidney injury was identified in 38/79 (48%) dogs and mostly occurred during hospitalization. Kidney injury was Grade I in 25 dogs, Grade II in 9 dogs, and Grade III in 4 dogs. Higher blood pressure was associated with acute KI during hospitalization (odds ratio, 1.03; 95% confidence interval [95% CI] 1.01-1.07; P = .03) whereas PO furosemide dosage was associated with KI after hospital discharge (odds ratio, 7.77; 95% CI, 2.05-68.6; P = .02). Baseline sCr and use of a furosemide continuous rate infusion were not associated with increased risk of KI. Kidney injury was not associated with long-term outcome. Of 13 dogs with Grade II-III KI, azotemia was reversible in 9 dogs, and 6 dogs survived >1 year after KI.

CONCLUSIONS AND CLINICAL IMPORTANCE

In this cohort of dogs receiving parenteral furosemide for CHF, KI was common, mostly nonazotemic (Grade I), and did not impact survival.

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.

DIAGNOSIS AND MANAGEMENT OF SUSPECTED CONGESTIVE HEART FAILURE SECONDARY TO DILATED CARDIOMYOPATHY IN A SAND TIGER SHARK (CARCHARIAS TAURUS) WITH ESTABLISHMENT OF PRELIMINARY NORMAL ECHOCARDIOGRAPHIC INDICES

Elasmobranch cardiac anatomy and physiology has been well described; however, there is a dearth of information regarding cardiac disease. In support of a clinical case of suspected congestive heart failure in a 22-yr-old male sand tiger shark (Carcharias taurus), a study was undertaken to identify feasible echocardiographic imaging planes and preliminary indices for this species. Eleven echocardiograms were performed on six apparently healthy sand tiger sharks. Echocardiographic parameters are presented using descriptive statistics, including mean, median, standard deviation (SD), minimum and maximum values. These data were utilized for the diagnosis and clinical management of the affected shark. The shark initially presented with increased respiratory effort, dependent, peripheral edema, and anemia. Echocardiography revealed atrial, ventricular, and sinus venosus dilation. As congestive heart failure secondary to dilated cardiomyopathy was strongly suspected, therapy was initiated with oral benazepril and torsemide, and later pimobendan. After a year of therapy, clinical signs resolved. Cardiac size and function improved on echocardiography with a reduction in sinus venosus dilation, maximum and minimum atrial and ventricular inner diameters, and an increase in atrial and ventricular fractional shortening. Cardiac disease in elasmobranchs may be underdiagnosed, so it may be necessary to develop standardized ultrasound techniques and cardiac measurements for each species of elasmobranch managed within zoos and aquaria.

Mitral valvuloplasty with left atrial appendage closure and pacemaker implantation in a dog with severe myxomatous mitral valve degeneration: a case report

Background

Mitral valvuloplasty (MVP) has been widely recognized as a treatment option for myxomatous mitral valve disease (MMVD). However, postoperative complications such as thromboembolism, arrhythmia, and pancreatitis in some cases have resulted in death. We treated a dog with severe MMVD complicated by impaired sinus function with MVP and pacemaker implantation. Also, due to an intrinsic procoagulant state and severe arrhythmia after the MVP, left atrial appendage (LAA) closure was performed to reduce the postoperative risk of thrombosis.

Case presentation

An 11-year-old castrated 7.5-kg male Miniature Schnauzer with a history of congestive heart failure was brought to Shiraishi Animal Hospital for MMVD surgical treatment. Echocardiography revealed an enlarged left atrium and ventricle secondary to MMVD. Sinus arrest with 2 to 3-second periods of asystole was identified by electrocardiogram. Mitral valvuloplasty was performed with cardiopulmonary bypass to treat the MMVD. After coronary reperfusion, there was no spontaneous electrical activity. Cardiac arrest continued. Based on this surgical outcome, a permanent pacemaker was implanted. In addition, LAA closure with an AtriClip was performed to prevent intra-atrial thrombus formation. Cardiac remodeling and congestion were ameliorated after surgery. Sinus rhythm was restored 5 days postoperatively; however, the patient continued pacemaker dependent. All cardiac drugs were discontinued 3 months after surgery. The owner reported no postoperative complications (i.e., thrombosis), and the patient was brought for a check-up 4 months after the operation in good health.

Conclusions

For surgical MMVD cases complicated with impaired sinus function, the chances of spontaneous sinus rhythm are low, requiring pacemaker implantation. LAA closure may be considered to protect against decreased atrial function after mitral valvuloplasty and prevent intra-atrial thrombus formation.

Computed tomographic assessment of principal bronchial anatomy in dogs of various thoracic conformations: 93 cases (2012-2017)

OBJECTIVE

To better understand spatial relationships between principal bronchi and other intrathoracic structures by use of CT images of dogs of various somatotypes.

ANIMALS

93 dogs that underwent thoracic CT.

PROCEDURES

Information was collected from medical records regarding signalment and physical examination and echocardiographic findings. Two investigators recorded multiple measurements on a thoracic axial CT image from each dog.

RESULTS

Thoracic height-to-width ratio (H:W) was associated with left principal bronchus (LPB) and right principal bronchus (RPB) H:W, aortic-LPB separation, focal LPB narrowing, and aortic-vertebral overlap. Thoracic H:W was not associated with dog age, weight, sex, or brachycephalic breed. Twenty-five (27%) dogs had focal LPB narrowing, compared with 5 (5%) dogs with focal RPB narrowing (P < 0.001). Ten of 25 dogs had overlap or contact between vertebrae, aorta, LPB, and heart, suggesting a cumulative compressive effect on the LPB, while 15 had LPB-aorta contact and lack of contact between the aorta and thoracic vertebrae, suggesting an aortic constrictive effect on the LPB. None had LPB narrowing without contact from surrounding structures. Inter-rater agreement was high.

CLINICAL RELEVANCE

In dogs that underwent CT and were not selected for clinical suspicion of bronchial disease, principal bronchial morphology was associated with thoracic conformation. Focal LPB narrowing occurred more often than RPB narrowing. Focal LPB narrowing occurred with evidence of extraluminal compression, with or without contact between aorta and vertebrae. Brachycephalic breed could not be used for predicting thoracic H:W.

Management of Chronic Congestive Heart Failure Caused by Myxomatous Mitral Valve Disease in Dogs: A Narrative Review from 1970 to 2020

Simple Summary

Myxomatous mitral valve disease (MMVD) is the most common acquired cardiovascular disease in dogs. The progression of the disease and the increasing severity of valvular regurgitation cause a volume overload of the left heart, leading to left atrial and ventricular remodeling and congestive heart failure (CHF). The treatment of chronic CHF secondary to MMVD in dogs has not always been the same over time. In the last fifty years, the drugs utilized have considerably changed, as well as the therapeutic protocols. Some drugs have also changed their intended use. An analysis of the literature concerning the therapy of chronic heart failure in dogs affected by this widespread degenerative disease is not available; a synthesis of the published literature on this topic and a description of its current state of art are needed. To the authors’ knowledge, a review of this topic has never been published in veterinary medicine; therefore, the aim of this study is to overview the treatments of chronic CHF secondary to MMVD in dogs from 1970 to 2020 using the general framework of narrative reviews.

Abstract

The treatment of chronic congestive heart failure (CHF), secondary to myxomatous mitral valve disease (MMVD) in dogs, has considerably changed in the last fifty years. An analysis of the literature concerning the therapy of chronic CHF in dogs affected by MMVD is not available, and it is needed. Narrative reviews (NRs) are aimed at identifying and summarizing what has been previously published, avoiding duplications, and seeking new study areas that have not yet been addressed. The most accessible open-access databases, PubMed, Embase, and Google Scholar, were chosen, and the searching time frame was set in five decades, from 1970 to 2020. The 384 selected studies were classified into categories depending on the aim of the study, the population target, the pathogenesis of MMVD (natural/induced), and the resulting CHF. Over the years, the types of studies have increased considerably in veterinary medicine. In particular, there have been 43 (24.29%) clinical trials, 41 (23.16%) randomized controlled trials, 10 (5.65%) cross-over trials, 40 (22.60%) reviews, 5 (2.82%) comparative studies, 17 (9.60%) case-control studies, 2 (1.13%) cohort studies, 2 (1.13%) experimental studies, 2 (1.13%) questionnaires, 6 (3.40%) case-reports, 7 (3.95%) retrospective studies, and 2 (1.13%) guidelines. The experimental studies on dogs with an induced form of the disease were less numerous (49–27.68%) than the studies on dogs affected by spontaneous MMVD (128–72.32%). The therapy of chronic CHF in dogs has considerably changed in the last fifty years: in the last century, some of the currently prescribed drugs did not exist yet, while others had different indications.

Analysis of canine cardiovascular therapeutic agent prescriptions using electronic health records in primary care veterinary practices in the United Kingdom

INTRODUCTION/OBJECTIVES

Canine cardiovascular (CV) diseases are often managed in primary care settings. The objectives were to describe CV therapeutic agent (CVTA) prescribing patterns in primary care practices in the United Kingdom (UK) and to evaluate recorded clinical signs, diagnostic tests and justifications for use of torasemide, a recently marketed and authorised loop-diuretic in the UK.

ANIMALS, MATERIALS AND METHODS

Electronic health records (EHRs) describing 3,579,420 consultations (1,043,042 unique dogs) were collated (1 April 2014 and 31 December 2018) by the Small Animal Veterinary Surveillance Network from 270 veterinary practices. Consultations prescribing at least one CVTA were identified. Annual variation in individual CVTA prescriptions was analysed using mixed-effects binomial regression models. Free-text clinical narratives were manually read to determine the first-prescribing event for torasemide.

RESULTS

Twenty-nine thousand and seven consultations (0.81% of all consultations, 95% confidence interval [CI], 0.76-0.86) prescribed CVTA in 14,148 (1.36%) dogs. Furosemide (52.8% of CV-prescribing consultations, 95% CI 50.7-54.9) and pimobendan (51.9%, 95% CI 50.1-53.7) were most prescribed. Longitudinal analysis (2014-2018) showed a significant negative temporal trend for angiotensin-converting enzyme inhibitors (p < 0.001), and furosemide (p = 0.003) and a positive temporal trend for pimobendan (p = 0.020) and torasemide (p < 0.001). First prescriptions of torasemide were identified in 16.5% of torasemide-prescribing consultations. Where justification for prescription of torasemide was identified (32.5%), furosemide resistance was the most common (92.0%).

CONCLUSIONS

EHRs can be used to temporally monitor prescribing habits, including responses to market authorisations. Despite authorisation in the UK for torasemide use as a first-line diuretic, it was most commonly prescribed after furosemide resistance.

Safety of torasemide in healthy adult dogs administered daily for 26 weeks

Thirty‐two (16 males and 16 females) healthy young beagles were randomly divided into four groups of eight. The control group remained untreated. Torasemide (ISEMID^®, Ceva Santé Animale) was orally administered, once daily, at 0.5 mg/kg from Days 1–5 then 0.25 mg/kg to Day 182, and at three times and five times this dosing regimen in two additional groups. Treated animals (predominantly at the higher dose levels) showed dryness of the oral mucosa, evidence of diuresis, decreased diet consumption, decreased bodyweight gain over the first 3 weeks, increased water consumption, increases in erythrocytes count, haemoglobin, calcium and magnesium, decrease in chloride, phosphorus, potassium and sodium, increases in urine pH, decreases in urine specific gravity and increases in serum aldosterone concentrations. Plasma concentrations of torasemide increased in a dose‐dependent manner and showed no evidence of accumulation. There were also changes to electrocardiogram patterns and the macroscopic and microscopic appearance of the kidney and adrenal glands, but these changes were almost exclusively confined to the over‐dosed groups. In conclusion, torasemide was found to be safe when administered to dogs at 0.25 mg/kg once daily for 26 weeks, and any changes were consistent with its known diuretic effects.

Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition

Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Evaluation of bronchial narrowing in coughing dogs with heart murmurs using computed tomography

Background

The origin of cough in dogs with heart murmurs is controversial, because the cough could be primary cardiac (eg, pulmonary edema, bronchi compression by left‐sided cardiomegaly) or respiratory (eg, bronchomalacia, other bronchial or bronchiolar disease, interstitial lung disease) in origin.

Hypothesis/Objectives

To study the association between left atrium (LA) dilatation and cardiomegaly and bronchial narrowing in coughing dogs with heart murmurs using computed tomography (CT).

Animals

Twenty‐one client‐owned coughing dogs with heart murmurs and 14 historical control dogs.

Methods

Dogs with cough and murmur were prospectively recruited over 4 months. Cervical and thoracic radiography, echocardiography, and thoracic CT were performed in enrolled dogs. Control dogs, with no disease on thoracic CT and no records of heart murmur and coughing, were gathered from the institution's computerized database. Degree of bronchial narrowing was assessed using the bronchial‐to‐aorta (Ao) ratio, measured by 3 radiologists blinded to the clinical findings. After identifying bronchi that were significantly narrowed in dogs with murmur compared to controls, the relationship between degree of narrowing and LA/Ao ratio (measured echocardiographically) and vertebral heart scale (VHS) measured radiographically was studied in dogs with murmur using mixed‐effects regression.

Result

Significant narrowing was identified for all left‐sided bronchi and the right principal, middle, and caudal bronchi in the coughing dogs, compared with controls. Increasing LA size and VHS were significantly inversely associated with diameter for all left‐sided and right‐sided bronchi indicated above.

Conclusion and Clinical Importance

Results indicate an association between LA enlargement and cardiomegaly and bronchial narrowing and support heart size‐associated exacerbation of cough in dogs with murmurs.

Tolerance of torasemide in cats with congestive heart failure: a retrospective study on 21 cases (2016-2019)

BACKGROUND

In dogs with congestive heart failure (CHF), the efficacy of torasemide, a loop diuretic, has been demonstrated. However, unlike in dogs and humans little has been described about the use of torasemide in the cat with spontaneous CHF. The objectives of this retrospective study were therefore to describe the therapeutic use of oral torasemide in cats with spontaneous CHF, document its potential adverse effects while reporting the clinical course of this feline population following torasemide administration in addition to standard medical therapy.

RESULTS

Medical records of 21 client-owned cats with CHF (median age = 10.6 years [interquartile range (IQR) = 6.5-11.2]) receiving torasemide were reviewed. Data collected included torasemide dosages, other concurrent medications, physical examination features, echocardiographic data, and potential adverse effects during follow-up. A survival analysis was performed to estimate the time from diagnosis to cardiac death. Dyspnea related to CHF was identified in all cats (pleural effusion [8/21], pulmonary edema [5/21] or both [8/21]), associated with ascites in 4/21 cats. The CHF cause was determined by echocardiography in all cats: hypertrophic (n = 10), restrictive (n = 6), arrhythmogenic right ventricular (n = 3), dilated (n = 1) cardiomyopathies, and aortic valve abnormality (n = 1). At initiation, median torasemide dosage was 0.21 mg/kg [IQR = 0.17-0.23] q24h. Clinical signs declined in most cats (20/21) during the first 2 weeks with no remarkable adverse events. Median survival time after torasemide prescription was 182 days [IQR = 46-330]. A contemporary control group including 54 cats with CHF, receiving furosemide as sole loop diuretic treatment was compared with the study group. Median (IQR) survival time of cats in the control group was not significatively different (p = 0.962) from that of the torasemide group, i.e., 148 days (9-364), although the torasemide group included significantly more cats with recurrent episodes of CHF (52%) that the control group (19%).

CONCLUSIONS

This case series demonstrates that torasemide can be used in cats with spontaneous CHF. This therapeutic interest needs to be confirmed by prospective clinical trials.

Tolerance of torasemide in cats with congestive heart failure: a retrospective study on 21 cases (2016-2019)

BACKGROUND

In dogs with congestive heart failure (CHF), the efficacy of torasemide, a loop diuretic, has been demonstrated. However, unlike in dogs and humans little has been described about the use of torasemide in the cat with spontaneous CHF. The objectives of this retrospective study were therefore to describe the therapeutic use of oral torasemide in cats with spontaneous CHF, document its potential adverse effects while reporting the clinical course of this feline population following torasemide administration in addition to standard medical therapy.

RESULTS

Medical records of 21 client-owned cats with CHF (median age = 10.6 years [interquartile range (IQR) = 6.5-11.2]) receiving torasemide were reviewed. Data collected included torasemide dosages, other concurrent medications, physical examination features, echocardiographic data, and potential adverse effects during follow-up. A survival analysis was performed to estimate the time from diagnosis to cardiac death. Dyspnea related to CHF was identified in all cats (pleural effusion [8/21], pulmonary edema [5/21] or both [8/21]), associated with ascites in 4/21 cats. The CHF cause was determined by echocardiography in all cats: hypertrophic (n = 10), restrictive (n = 6), arrhythmogenic right ventricular (n = 3), dilated (n = 1) cardiomyopathies, and aortic valve abnormality (n = 1). At initiation, median torasemide dosage was 0.21 mg/kg [IQR = 0.17-0.23] q24h. Clinical signs declined in most cats (20/21) during the first 2 weeks with no remarkable adverse events. Median survival time after torasemide prescription was 182 days [IQR = 46-330]. A contemporary control group including 54 cats with CHF, receiving furosemide as sole loop diuretic treatment was compared with the study group. Median (IQR) survival time of cats in the control group was not significatively different (p = 0.962) from that of the torasemide group, i.e., 148 days (9-364), although the torasemide group included significantly more cats with recurrent episodes of CHF (52%) that the control group (19%).

CONCLUSIONS

This case series demonstrates that torasemide can be used in cats with spontaneous CHF. This therapeutic interest needs to be confirmed by prospective clinical trials.

Efficacy of oral torasemide in dogs with degenerative mitral valve disease and new onset congestive heart failure: The CARPODIEM study

Background

Torasemide is a potent loop diuretic with potential to treat congestive heart failure (CHF) in dogs.

Objective

Evaluate the efficacy and safety of torasemide compared to furosemide in dogs with first occurrence of CHF caused by degenerative mitral valve disease (DMVD).

Animals

Three hundred and nineteen dogs with new onset CHF attributable to DMVD.

Methods

Double‐blinded randomized noninferiority study of PO torasemide vs furosemide in addition to standard CHF treatment. The primary efficacy criterion was decreased pulmonary edema and cough and no worsening of dyspnea or exercise tolerance at day 14. Secondary endpoints included clinical response at day 84 and time to death, euthanasia, or premature study withdrawal for cardiac reasons.

Results

Torasemide q24h (n = 161) was noninferior to furosemide q12h (n = 158); percentage of dogs meeting primary efficacy criterion at day 14 was similar between groups (torasemide, 74.4% [95% confidence interval (CI), 66.8%‐81.0%] vs. furosemide, 73.5% [95% CI, 65.7%‐80.4%]; risk ratio [RR], 1.01; 95% CI, 0.89‐1.15; P = .87). Efficacy at day 84 showed similar results (RR, 1.05; 95% CI, 0.88‐1.25; P = .6). Dogs receiving torasemide had a longer time to endpoint and were less than half as likely to experience death, euthanasia, or premature study withdrawal (hazard ratio, 0.36; 95% CI, 0.19‐0.65; P = .001) than dogs receiving furosemide at any time during the study.

Conclusion and Clinical importance

Torasemide was noninferior to furosemide as first line PO treatment for new onset CHF caused by DMVD. Torasemide significantly decreased risk of cardiac‐related death or premature study withdrawal for cardiac reasons compared to furosemide.

Comparison between the effects of torsemide and furosemide on the renin-angiotensin-aldosterone system of normal dogs

INTRODUCTION/OBJECTIVES

We hypothesized that torsemide and furosemide, at approximately equipotent dosages (similar diuresis), would have comparable effects on the circulating renin-angiotensin-aldosterone system.

ANIMALS, MATERIALS AND METHODS

Six, healthy, middle-aged, male Beagles were randomized to receive torsemide (0.1 mg/kg PO q 12 h), furosemide (2.0 mg/kg PO q 12 h), or placebo for 10 days during three separate periods, separated by a 10-day washout period, in a crossover design. Blood was collected on days 1, 5, and 9 and 24-h urine collection ended on days 2, 6, and 10. After repeated measures analysis and Bonferonni correction, variables with an adjusted p<0.05 were investigated further, using Tukey's method.

RESULTS

Twenty-four-hour urine production differed significantly between the diuretics only on day 10, with torsemide causing a 38% greater diuresis than furosemide. There was, however, no significant difference in average 3-day diuresis. There were no significant differences between diuretics in the 24-h urinary excretion of sodium, chloride, or potassium, though furosemide caused less kaliuresis than torsemide. Serum renin, angiotensin II, and aldosterone and the urine aldosterone-to-creatinine ratio were significantly increased in the diuretic groups, as compared to placebo on days 5/6 and 9/10. There were no significant differences in these values between diuretics. Creatinine and blood urea nitrogen concentrations rose comparably in the diuretic groups, remaining within reference intervals in all dogs.

CONCLUSIONS

At approximately equipotent dosages (20:1), torsemide and furosemide produced comparable renin-angiotensin-aldosterone system activation. Torsemide's similar potassium excretion profile to furosemide decreases support for a hypothesized mineralocorticoid-receptor blocking capability.

ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs

This report, issued by the ACVIM Specialty of Cardiology consensus panel, revises guidelines for the diagnosis and treatment of myxomatous mitral valve disease (MMVD, also known as endocardiosis and degenerative or chronic valvular heart disease) in dogs, originally published in 2009. Updates were made to diagnostic, as well as medical, surgical, and dietary treatment recommendations. The strength of these recommendations was based on both the quantity and quality of available evidence supporting diagnostic and therapeutic decisions. Management of MMVD before the onset of clinical signs of heart failure has changed substantially compared with the 2009 guidelines, and new strategies to diagnose and treat advanced heart failure and pulmonary hypertension are reviewed.

Cardiorenal and endocrine effects of synthetic canine BNP1-32 in dogs with compensated congestive heart failure caused by myxomatous mitral valve disease

Background

The effects of synthetic brain natriuretic peptide (BNP1‐32) on cardiorenal and renin angiotensin aldosterone system in dogs with naturally occurring congestive heart failure (CHF) are unknown.

Objectives

To evaluate the cardiorenal and endocrine effects of SC administered synthetic canine BNP1‐32, with or without furosemide, in dogs with CHF caused by myxomatous mitral valve disease (MMVD).

Animals

Seven client‐owned male dogs with compensated American College of Veterinary Internal Medicine stage C CHF caused by MMVD on chronic treatment with furosemide, benazepril, and pimobendan.

Methods

A single‐dose, crossover, pilot study. Each dog received a dose of BNP1‐32 (5 μg/kg), furosemide (2 mg/kg), and both BNP1‐32/furosemide (5 μg/kg and 2 mg/kg, respectively) SC with a 2‐week washout period among each treatment. Between‐ and within‐treatment effects were evaluated using linear mixed modeling with restricted maximum likelihood estimation and evaluation of least square differences.

Results

Rapid absorption of BNP1‐32 and a corresponding rise in urinary cyclic guanosine monophosphate excretion was observed at 1‐2 hours after any treatment containing BNP1‐32 (P < .05). However, BNP1‐32 did not influence measured cardiorenal variables. Plasma aldosterone concentrations were below quantifiable levels in majority of the samples.

Conclusions and Clinical Importance

No beneficial cardiorenal effects were detected. It is possible that dogs with chronic CHF have a reduction in natriuretic peptide responsiveness.

Coughing in dogs: what is the evidence for and against a cardiac cough?

Cough has been historically reported as a major clinical sign of cardiogenic pulmonary oedema in dogs. However, recent evidence appears to contradict the traditional dogmatic approach that linked cough to congestive heart failure in dogs. Here we use a question-based format to introduce and discuss the modern evidence regarding "cardiac cough" and the interpretation of this important but often misleading clinical sign.