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Update on Nutritional Cardiomyopathy

As many of you are aware, we continue to investigate the link between receipt of unique/boutique diets and the development of dilated cardiomyopathy (DCM). Although the exact cause has not been elucidated, a correlation between diets primarily with ‘grain-free’, legume (peas, lentils), and potato-based food sources is apparent. In some patients, this may also involve a deficiency in taurine, however many affected patients have taurine levels that measure within the normal reference range. A genetic predisposition may also play a role.

The FDA originally released a statement regarding this phenomenon in July 2018, and since that time has provided several updates including a list of reported breeds and implicated diets to date. Most recently, a virtual scientific session entitled ‘Scientific Forum Exploring Causes of Dilated Cardiomyopathy in Dogs’ was hosted by Kansas State University on September 29, 2020, in which leaders in veterinary cardiology, nutrition, toxicology, as well as industry and the FDA gathered to provide the most recent information on this subject. Among the most interesting information provided is a look by the FDA of fully and partially recovered cases of DCM in dogs. To date, over 1,100 reports of diet-related DCM has been recognized in dogs and 20 in cats.

Although the incidence and extent is variable, as noted in the most recent KSU scientific sessions, improvement in cardiac size and function can occur with timely recognition, diet change, taurine supplementation, and supportive therapies (see below). Unfortunately, some patients also progress despite corresponding treatments and succumb due to complications such as congestive heart failure (CHF) and/or significant arrhythmias. As a result, an awareness of this association with appropriate diagnostics and education to our clients is essential.

Case examples:

Stella 1

 

 

Stella 2

 

Case 1: Sequential right parasternal short axis images from Stella, a 6 year old FS Goldendoodle fed a grain-free diet for the prior 18 months. On the initial evaluation on 9/11/18, she demonstrates moderate left ventricular dilation and significantly reduced systolic function (FS = 10%). Following diet change, taurine supplementation, and pimobendan therapies, she demonstrated noticeable improvement approximately 4 months thereafter (FS = 17%).

 

 

Boone 1

 

 

Boone 2

 

Case 2: Right parasternal short axis images from Boone, a 4 year old MN Bloodhound fed a grain-free diet his whole life. On initial evaluation also on 9/11/2018, he demonstrated severe left ventricular dilation, ventricular arrhythmias, and left-sided congestive heart failure (FS = 8%). Despite diet change, taurine supplementation, treatment for CHF (furosemide, benazepril, pimobendan), and anti-arrhythmic therapy (mexiletine and sotalol), he progressed on a subsequent recheck evaluation (FS = 7%) and ultimately died suddenly due to a fatal arrhythmia.

What to do?

As the exact cause for this phenomenon remains unclear, additional data is necessary. For cases in which there is a known or suspected nutritional cause of dilated cardiomyopathy, the following steps are advised:

  • Cardiac workup (echocardiography, thoracic radiographs, ECG, blood pressure)
  • Measurement of whole blood and plasma taurine levels (typically sent to UC Davis Amino Acid Laboratory)
  • If possible, screening of all other canines within household consuming same diet
  • Save samples of all diets and treats being fed including product labels
  • Report case and dietary information to FDA (https://www.fda.gov/AnimalVeterinary/SafetyHealth/ReportaProblem/ucm182403.htm)
  • Transition to alternative diet with standard ingredients (chicken, brief, rice, corn, wheat)
  • Taurine supplementation
  • Corresponding treatment for DCM as indicated based upon the clinical scenario
    • Pimobendan/Vetmedin
    • ACE-inhibitors
    • Diuretic therapy (furosemide, spironolactone)
    • Anti-arrhythmic medications
  • Following up diagnostics (particularly repeat echocardiography) in 3-6 months.

 

Click here to learn more about using real-time, sonographer assisted veterinary ultrasound to perform echocardiograms in your practice.

 

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