Birman Cat HCM Screening: A Complete Guide from Start Age to Screening Intervals

HeartBreed HealthMeongsiljang Veterinary Advisory Board

Birman cats are a breed at risk for hypertrophic cardiomyopathy (HCM). We’ll share the recommended schedule for regular cardiac ultrasound screenings starting at one year of age, along with key points for early detection.

Why Is Screening Important for Birman Cats and HCM?

A Birman cat undergoing an echocardiogram

Hypertrophic cardiomyopathy (HCM) is the most common myocardial disease in cats and often runs in families. The key to managing this condition is early detection. Because HCM can remain asymptomatic until it suddenly manifests as respiratory distress or hindlimb paralysis due to arterial thromboembolism, regular cardiac ultrasound screenings are essential for catching it early. Unlike Maine Coons and Ragdolls, which have clearly identified MYBPC3 gene mutations, Birman cats do not yet have an established breed-specific mutation. However, for Birman kittens with a family history of the disease, it is safest to begin cardiac ultrasound screenings around one year of age.

What Exactly Is HCM?

Hypertrophic cardiomyopathy (HCM) is a condition in which the heart muscle—particularly the wall of the left ventricle—abnormally thickens. This thickening narrows the chamber inside the heart, preventing it from filling with enough blood. As a result, fluid can accumulate in the lungs (pulmonary edema) or blood clots may form and block the arteries supplying the hind limbs, a condition known as arterial thromboembolism. According to veterinary cardiology textbooks, feline HCM follows an autosomal dominant inheritance pattern with incomplete penetrance, meaning that even among cats carrying the same genetic mutation, the way the disease manifests can vary.

Key Screening Points Birman Owners Must Remember

For Birman cats, please keep the following points in mind:

When to start screening: A first echocardiogram is recommended around 12 months of age.

Screening frequency: For breeding cats, annual screenings are advised from ages 1 to 3, with follow-up checks at ages 5 and 8.

Essential tests: Echocardiography (echo) is the most sensitive standard test; it should be performed alongside auscultation and blood pressure measurement.

Additional recommendations: Blood tests for cardiac biomarkers, such as NT-proBNP, are recommended to assist with monitoring.

Breeding criteria: Normal heart function must be confirmed via echocardiography before breeding.

If there is a family history of HCM in parents or siblings, or if early changes have already been detected, it is safer to schedule more frequent check-ups every 6 to 12 months, depending on the severity of the condition.

Illustration of a Birman cat heart screening checklist

Recommended Screening Intervals by Age

Item	Low risk (no family history)	Moderate risk (relative diagnosed)	High risk (parent/sibling diagnosed)
12 months (first screening)	Basic echocardiography	Basic echocardiography	Echocardiography + blood pressure
1–3 yr	Every 2 years	Every year	Every 6–12 months
4–7 yr	Every 1–2 years	Every year	Every 6–12 months
8+ yr	Every year	Every year	Every 6–12 months
Just before breeding	Once, mandatory	Once, mandatory	Once, mandatory

Interpretation by a veterinary cardiologist is recommended. Feline HCM can progress without a murmur, so it may be missed by auscultation alone; echocardiography is the most sensitive standard test.

How Is the Cardiac Ultrasound Performed?

The procedure itself typically takes about 20 to 40 minutes. A small area of fur on the chest is shaved, gel is applied, and an ultrasound probe is used to measure the thickness and movement of the heart walls, as well as blood flow across the valves. Anesthesia is rarely required; however, anxious cats may receive mild sedation. Fasting before the exam may be recommended, so please check with your clinic in advance. The results are interpreted by evaluating factors such as left ventricular wall thickness and whether the left atrium is enlarged. In cats, the patterns of hypertrophy vary widely, and there is no complete consensus among experts on the exact cutoffs for normal wall thickness. Therefore, interpretation by an experienced examiner—ideally a board-certified veterinary cardiologist—is crucial.

A veterinarian performing an echocardiogram on a Birman cat

If You See These Signs, Go to the Vet Immediately Regardless of Schedule

Even if you have a scheduled echocardiogram appointment, please visit a veterinary clinic as soon as possible (within 24 hours) if any of the following signs appear: • Open-mouth breathing or panting • Sudden weakness or coldness in the hind legs • A noticeably faster breathing rate while sleeping compared to normal • Pale or bluish gums • Sudden loss of appetite and lethargy In particular, hind limb paralysis is an emergency sign of arterial thromboembolism. Delaying treatment can make recovery difficult.

Can Genetic Testing Help?

Unlike Maine Coons (MYBPC3 A31P) and Ragdolls (MYBPC3 R820W), which have well-established commercial tests for breed-specific mutations, such tests are not yet available for Birman cats. In fact, commercially available genetic tests are only validated for the MYBPC3 mutations in Maine Coons and Ragdolls and do not apply to other breeds. Therefore, a "negative" result from a commercial test does not mean there is zero risk of developing hypertrophic cardiomyopathy (HCM). Cats with a negative genotype can still develop HCM later in life, while those with a positive genotype may never show symptoms. Ultimately, regular cardiac echocardiography remains the most reliable method for detection. Given the complex genetic background of HCM—even in humans, where over 1,400 variants across more than 14 genes have been identified—it is advisable for breeding cats to have their latest genetic information reviewed at a specialized clinic. For more details, please refer to our Cat Echocardiography Guide.

Management Points for Early Detection

If your pet is diagnosed with early-stage HCM (characterized by mild thickening of the left ventricular wall), the following management strategies are typically recommended:

Weight Management: Maintain an ideal body weight, as obesity increases the workload on the heart.

Minimize Stress: Avoid environmental changes, loud noises, and vigorous play.

Monitor Respiratory Rate: Record the resting respiratory rate (breaths per minute) once a week while your pet is sleeping.

Medication: Treatment may be initiated based on your veterinarian’s prescription if progression occurs, such as left atrial enlargement.

Sodium Control: Avoid human food and salty treats.

Your veterinarian will determine the appropriate medications and dosages based on your pet’s specific cardiac condition.

Other Health Issues to Watch for in Birman Cats

In addition to heart concerns, Birman cats may be predisposed to certain congenital and genetic conditions that warrant attention. Preventive medicine textbooks emphasize reviewing "congenital and genetic diseases" and "breed-specific health predispositions" at each life stage as part of routine health management. In Birmans, issues such as sparse or absent coat in kittens, immune system vulnerabilities, and occasionally observed neutrophil granule abnormalities on blood tests have been noted; however, the specific risks and prognosis vary from individual to individual. Rather than relying on definitive statistics, the safest approach is to carefully review the breeder’s health screening records and family history before adoption or breeding, and to consult with your veterinarian.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

At what age should a Birman cat start having heart screenings?

We recommend starting with the first echocardiogram at 12 months of age (one year old). If there is a family history of HCM in parents or siblings, you can begin screenings as early as 6 to 9 months.

Isn't a stethoscope exam enough?

That’s not enough. A significant number of cats with HCM progress without any detectable heart murmurs on auscultation. Echocardiography is the most definitive diagnostic test.

How much does the check-up cost?

Costs vary widely depending on the clinic and location, so it's difficult to provide an exact figure. I recommend comparing estimates from a local veterinary clinic and a secondary care facility that offers specialized cardiac diagnostics.

Can genetic testing help identify the risk of HCM in advance?

The Birman-specific mutation has not yet been established as a commercially available test. At this time, regular cardiac ultrasound is the most reliable method.

What is the average life expectancy after an HCM diagnosis?

If detected in the early, asymptomatic stage, many pets can maintain a lifespan close to normal. However, the prognosis changes when left atrial enlargement or pulmonary edema is present, making early detection crucial.

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References

[1] Little, S. E., The Cat: Clinical Medicine and Management, 2nd Edition, 2024

[2] Textbook of Cardiovascular Medicine in Dogs and Cats — Feline Hypertrophic Cardiomyopathy chapter

[3] ACVIM Consensus Statement on Feline Cardiomyopathy, 2020