Related Experiment Video
Updated: Oct 15, 2025
Investigating the Pathogenesis of MYH7 Mutation Gly823Glu in Familial Hypertrophic Cardiomyopathy using a Mouse Model
Published on: August 8, 2022
The Feline Cardiomyopathies: 3. Cardiomyopathies other than HCM
Mark D Kittleson1, Etienne Côté2
1School of Veterinary Medicine, Department of Medicine and Epidemiology, University of California, Davis, and Veterinary Information Network, 777 West Covell Boulevard, Davis, CA 95616, USA.
Insights
Feline hypertrophic cardiomyopathy (HCM) is common, but other cardiomyopathies like dilated (DCM) and restrictive (RCM) are recognized. Echocardiography is key for diagnosis, though treatment often remains similar across feline cardiomyopathy types.
Area of Science:
- Veterinary Cardiology
- Feline Medicine
- Cardiovascular Research
Background:
- Feline hypertrophic cardiomyopathy (HCM) is the most common cardiac disease in cats.
- Other cardiomyopathies, including dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), left ventricular noncompaction (LVNC), and cardiomyopathy - nonspecific phenotype (NCM), are also recognized in domestic cats.
- These less common cardiomyopathies are often diagnosed late, typically when cats present with heart failure or thromboembolic disease.
Purpose of the Study:
- To review the recognition, diagnosis, and management of non-HCM cardiomyopathies in domestic cats.
- To highlight the diagnostic role of echocardiography in differentiating feline cardiomyopathies.
- To discuss the clinical presentation and treatment similarities among various feline cardiomyopathy types.
Main Methods:
- Review of existing literature on feline cardiomyopathies.
- Echocardiographic findings for different cardiomyopathy types (RCM, DCM, ARVC, LVNC, NCM).
- Comparison of clinical presentations and treatment strategies for HCM and other feline cardiomyopathies.
Main Results:
- Non-HCM cardiomyopathies are rarely suspected in subclinical cats and are often identified during advanced disease stages.
- Echocardiography is the definitive diagnostic tool for confirming feline cardiomyopathies.
- While distinct echocardiographic criteria exist for RCM, DCM, ARVC, and LVNC, the nonspecific phenotype (NCM) encompasses cases not fitting specific criteria or meeting multiple criteria.
- Treatment for heart failure, thromboembolism, and other consequences is generally consistent across different feline cardiomyopathy diagnoses.
Conclusions:
- The clinical and radiographic signs of feline cardiomyopathies can be indistinguishable from HCM.
- Echocardiography is crucial for ante-mortem diagnosis, but distinguishing between types is not always essential for guiding therapy due to similar prognoses and treatments.
- Further research into interrelationships among feline cardiomyopathies may offer critical insights for future treatment and prognosis.
Practical Relevance:
Although feline hypertrophic cardiomyopathy (HCM) occurs more commonly, dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), left ventricular noncompaction (LVNC) and cardiomyopathy - nonspecific phenotype (NCM; formerly unclassified cardiomyopathy) are all recognized in domestic cats.
Patient Group:
Any adult domestic cat, of either sex and of any breed, can be affected.
Diagnostics:
The non-HCM cardiomyopathies are rarely suspected in subclinically affected cats, so most are first identified when a cat presents with signs of heart failure or systemic thromboembolic disease. The definitive clinical confirmatory test for these other feline cardiomyopathies is echocardiography.
Key Findings:
'Cardiomyopathy - nonspecific phenotype' is a catch-all term that groups hearts with myocardial changes that either do not meet the criteria for any one type of cardiomyopathy (HCM, RCM, DCM, ARVC, LVNC) or meet the echocardiography criteria for more than one type. RCM is characterized by diastolic dysfunction due to fibrosis that results in a restrictive transmitral flow pattern on Doppler echocardiography and usually marked left or biatrial enlargement. DCM is characterized by decreased myocardial contractility and is rare in cats. When it occurs, it is seldom due to taurine deficiency. However, since taurine-deficient DCM is usually reversible, a diet history should be obtained, whole blood and plasma taurine levels should be measured and taurine should be supplemented in the diet if the diet is not commercially manufactured. ARVC should be suspected in adult cats with severe right heart enlargement and right heart failure (ascites and/or pleural effusion), especially if arrhythmia is present. Feline LVNC is rare; its significance continues to be explored. Treatment of the consequences of these cardiomyopathies (management of heart failure, thromboprophylaxis, treatment of systemic arterial thromboembolism) is the same as for HCM.
Conclusions:
While these other cardiomyopathies are less prevalent than HCM in cats, their clinical and radiographic presentation is often indistinguishable from HCM. Echocardiography is usually the only ante-mortem method to determine which type of cardiomyopathy is present. However, since treatment and prognosis are often similar for the feline cardiomyopathies, distinguishing among the cardiomyopathies is often not essential for determining appropriate therapy.
Areas Of Uncertainty:
The feline cardiomyopathies do not always fit into one distinct category. Interrelationships among cardiomyopathies in cats may exist and understanding these relationships in the future might provide critical insights regarding treatment and prognosis.
More Related Videos
Related Concept Videos
01:25Cardiomyopathy I: Introduction and Classification
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:29Cardiomyopathy V: Interprofessional Care
01:29Cardiomyopathy VI: Nursing Management