If you’ve heard of hypertrophic cardiomyopathy (HCM) in cats, you know it’s a disease that can strike without warning. HCM is the most common heart disease in cats, causing thickening of the heart muscle that may eventually lead to heart failure, blood clots, or sudden death. Understandably, breeders and pet owners alike want reliable ways to detect it early.
But is a ProBNP blood test enough to catch HCM before it progresses?
What Is a ProBNP Test?
The ProBNP (or NT-proBNP) test measures levels of a biomarker released when the heart muscle is stretched or stressed. High levels can indicate that a cat’s heart is working harder than normal, which often happens in cardiac diseases like HCM.
Veterinary clinics sometimes use ProBNP as:
- A screening tool for apparently healthy cats
- A diagnostic aid when heart disease is suspected based on physical exam or symptoms
- A monitoring tool for cats with known heart conditions
The Problem With Relying Solely on ProBNP
While ProBNP testing is a useful tool, it has limitations:
- Early or mild HCM often does not cause elevated ProBNP levels. Cats can have thickening of their heart muscle before enough stress occurs to increase biomarkers. This means a cat with early HCM may have a normal ProBNP result despite disease presence. [1]
- Elevated ProBNP is not specific to HCM. Levels can rise with other conditions that strain the heart, such as hyperthyroidism, hypertension, kidney disease, or severe dehydration. [2]
- False negatives and false positives can occur. Using ProBNP alone could provide a false sense of security or cause unnecessary worry.
Why Early Detection of HCM Matters – Especially with New Treatments
Many cats with HCM show no outward signs until the disease is advanced. By the time a cat experiences breathing difficulties, weakness, or sudden paralysis from blood clots, irreversible damage may have occurred.
Emerging therapies like delayed-release rapamycin are showing promise for HCM treatment. Studies suggest rapamycin can partially reverse or reduce heart muscle thickening in cats with early or mild HCM, improving heart function and potentially slowing disease progression. [3]
However, it is important to understand:
- Rapamycin is most effective before permanent changes occur.
- Once significant scarring (fibrosis) develops in the heart muscle, damage is irreversible.
- ProBNP testing alone will not reliably catch early or mild HCM, as biomarker levels often remain normal until disease is more advanced.
This means relying solely on ProBNP testing can result in missed opportunities for early treatment. An echocardiogram remains the only way to directly visualize heart changes before biomarkers rise, allowing intervention when therapies like rapamycin have the highest chance of success.
What’s the Best Screening Method for HCM?
Echocardiogram: The Gold Standard
A veterinary echocardiogram (often called an HCM scan) performed by a cardiologist remains the most reliable way to detect HCM. It allows direct measurement of heart wall thickness and chamber size, identifying even mild disease.
Where Does ProBNP Fit In?
ProBNP can still be helpful:
- As an adjunct screening tool when echocardiography is unavailable or unaffordable
- To prioritize cats for referral to a cardiologist if ProBNP is elevated
- As a monitoring tool in cats already diagnosed with cardiac disease
However, normal ProBNP does not rule out early or mild HCM, so relying solely on this test may result in missed diagnoses.
The Bottom Line
If you are a breeder aiming to produce healthy kittens or a pet owner wanting peace of mind, ProBNP testing can be part of your cat’s cardiac screening, but it should not replace an echocardiogram—especially for high-risk breeds.
Early detection of HCM saves lives, informs responsible breeding decisions, and gives you the chance to intervene before symptoms appear. As treatments like rapamycin continue to develop, catching HCM before permanent damage occurs becomes more important than ever.
References
- Luis Fuentes V, Abbott J, Chetboul V, et al. ACVIM consensus statement guidelines for the classification, diagnosis, and management of cardiomyopathies in cats. J Vet Intern Med. 2020;34(3):1062-1077. doi:10.1111/jvim.15745
- Fox PR, Rush JE, Reynolds CA, et al. Multicenter evaluation of plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) concentration for assessing risk of heart disease in cats. J Vet Intern Med. 2011;25(5):1016-1024. doi:10.1111/j.1939-1676.2011.00790.x
- Côté E, O’Sullivan ML, MacDonald KA, et al. Effect of short-term low-dose rapamycin on cardiac hypertrophy in cats with subclinical hypertrophic cardiomyopathy: a pilot study. J Vet Cardiol. 2021;36:66-76. doi:10.1016/j.jvc.2021.01.004
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Meta Title: Is ProBNP Testing Enough to Detect HCM in Cats?
Meta Description: Learn why ProBNP tests alone aren’t enough to detect early hypertrophic cardiomyopathy (HCM) in cats, how emerging treatments like rapamycin work, and the importance of early screening.
Target Keywords: HCM in cats, ProBNP test cats, cat heart disease screening, early detection HCM cats, rapamycin for cats
