Dilated cardiomyopathy in an American cocker spaniel with taurine deficiency

Low plasma taurine levels in English cocker spaniels diagnosed with dilated cardiomyopathy

OBJECTIVES

The aims of this study were to evaluate taurine levels in English cocker spaniels with dilated cardiomyopathy and assess their survival time and natural progression of their disease.

MATERIALS AND METHODS

Retrospective comparison of English cocker spaniels with dilated cardiomyopathy phenotype with and without taurine deficiency at the cardiology department of a UK academic referral centre between 2008 and 2018.

RESULTS

Taurine plasma concentration was available in 16 English cocker spaniels with dilated cardiomyopathy phenotype; 13 of 16 had congestive heart failure and three of 16 did not. Taurine concentration was low (<50 μmol/L) in 13 of 16 and normal in three of 16. Deficient dogs received taurine supplementation in addition to conventional cardiac medications. Eight dogs were still alive at the end of this study and eight were dead. MST for all dogs included in the study was 2800 days. Left ventricular systolic function improved and left ventricular dimensions reduced in English cocker spaniels with taurine deficiency following taurine supplementation and conventional cardiac therapy, although similar results were observed in English cocker spaniels with normal taurine concentration on cardiac therapy alone.

CLINICAL SIGNIFICANCE

Based on laboratory reference intervals, low taurine concentrations were common in English cocker spaniels with dilated cardiomyopathy, showing a possible association between dilated cardiomyopathy in English cocker spaniels and taurine deficiency; supplementation with taurine was not curative.

Traditional and nontraditional effective and noneffective therapies for cardiac disease in dogs and cats

In this article, I presented my (admittedly biased) perspective of the current state of knowledge addressing the role of traditional and non-traditional therapeutics. The focus has been on the nontraditional therapeutics. Among these, the only ones I currently consider to have any documented value are taurine and, less commonly, L-carnitine. The role of taurine (and likely carnitine) remains limited to cases of documented deficiency. In the case of cats with taurine deficiency-induced myocardial failure, it is now clear that most cases are the result of formulation errors by owners and manufacturers. In dogs, it is less clear if the causes of taurine deficiencies represent manifestations of pathologic conditions or dietary formulations errors. Increasingly, it seems the latter may prove to be the case in most, if not all, circumstances. Finally, I would like to reiterate the conclusions of the last time I addressed this topic (with coauthors Kittleson and Sanderson) in this publication. Remember that there is limited evidence to support the therapeutic recommendations you read or hear in most circumstances. The urge to do "something" for patients can be overwhelmingly attractive. Nevertheless, whether it is administration of drugs or prescribing nutraceuticals or prescription diets, strongly consider the source of the information urging you to prescribe, the strength of the evidence presented, the financial costs to the owner, and the potential risks and benefits to the patient.

Taurine status in normal dogs fed a commercial diet associated with taurine deficiency and dilated cardiomyopathy

Taurine (Tau) deficiencies have been associated with the feeding of commercial lamb-meal and rice diets to dogs. We hypothesized that the poor digestibility of some lamb-meals may limit sulphur amino acids availability for Tau synthesis and/or increase of Tau degradation in the gut. Growing dogs were fed either a lamb-meal-based (Diet A) or poultry by-product-based (Diet B) commercial diet. Plasma, whole blood and urinary Tau were measured for 22 weeks. Plasma and whole blood Tau concentrations were similar between the groups throughout the study. Urinary excretion of Tau in dogs fed diet A was 3.2 times greater than that from dogs fed Diet B, suggesting greater renal reabsorption and the need for conservation of Tau in the Diet A group. Food restriction affected Tau status as indicted by a positive correlation of food intake and urinary Tau. Dogs fed Diet A were given antibiotics to inhibit bacterial activity in the gut. Increases in breath hydrogen, indicative of increased bacterial activity, correlated negatively with urinary Tau. Urinary Tau increased by 54% when methionine (Met) was supplemented to Diet A, supporting the suggestion of a low bioavailability of sulphur amino acids and/or an increased fecal loss of Tau in dogs consuming Diet A.

Dilated cardiomyopathy in Presa canario dogs: ECG findings

Forty-seven Presa canario dogs were diagnosed with congestive heart failure due to dilated cardiomyopathy (DCM). Supraventricular or ventricular tachydysrhythmias were found in 29 dogs. Atrial fibrillation was the most common dysrhythmia. Ventricular dysrhythmias were observed infrequently and had a very important prognostic value in Presa canario dogs with DCM. Abnormalities of cardiac conduction were diagnosed in 16 (34%) dogs and changes in wave morphology were found in 29 (62%) dogs. Normal sinus rhythm was recorded in only 12 (26%) Presa canario dogs with DCM.

The effectiveness of taurine and levocarnitine in dogs with heart disease

In this article, the current state of knowledge of the potential role of taurine and L-carnitine deficiency and supplementation in the genesis and management of cardiovascular disease in dogs is presented. There is limited direct evidence to support the recommendations found in this article or elsewhere in the literature. The temptation to "do something" for our patients can be overwhelming. Whether it be the administration of drugs or prescribing nutraceuticals or prescription diets, the veterinarian should strongly consider the source of the information, the strength of the evidence presented, the financial costs to the owner, and the potential risks and benefits to the patient.