Hypertrophic cardiomyopathy (hcm)

Hypertrophic cardiomyopathy (HCM)
Hypertrophic cardiomyopathy (HCM) is a health concern in many pure breed cats. A link has recently been found between Savannah Cats and HCM; there are cases that indicate that HCM may also be a reoccurring health issue in some wild cats. Several Savannah Breeders have their breeder cats scanned for HCM on an annual basis..

What is HCM?

HCM is a disease which can cause sudden death and causes the thickening of the heart muscle which results in poor relaxing and filling ability. HCM can be very gradual but be detected via an ultrasoung scan. The pumping chamber also known as the ventricle becomes progressively thicker and less blood enters the chamber. The result of this means that less blood is released out to the body.

How is it detected and what's the cost?

HCM is detectable through an ultrasound scan ranging in cost between £120 - £180 per cat, per scan but discounts are often offered for bulk bookings. If you are interested in receiving a discount on your HCM Scans then please contact us.

Many breeders decide not to scan because of the high expense of these scans and because the disease can occur after a scan, so it requires repeat testing to check for the disease. HCM is a known disease in bengals and so, therefore, it can only be assumed that Savannahs are affected in their lineage. The only way to be sure is to test.

Auscultation (examining with a stethoscope)

• Your vet has likely checked your cat/ kittens heart with a stethoscope at a health check. This is an essential part of examining the heart and circulation. It can be difficult for a vet to identify any problems with a stethoscope as surgeries are often noisy, cats don't like to sit still, happy to sit still but purr the whole time (!) or are terrified. All these different situations mean that diagnosing a heart murmur for example can be difficult because some murmurs increase or alter at different heart rates. If a significant murmur is found then careful notes will be made including a grading of 0 - 6. Your cats heart rhythm will also be noted. Any significant murmur will require further investigation. ALWAYS make your breeder aware of any heart murmurs discovered, even on an annual health check because they will need to try and discover if there is a problem in their lines.
  
• Auscultation does not provide a conclusive diagnosis in any case. IF you intend to breed from your cat then it is highly recommended that you have your kittens heart checked when they reach one year old by a Veterinary Cardiologist. They will have trained specifically in cardiology and be more rigorous and specific in their checks than a Veterinary Surgeon, it can be assumed.

Electrocardiogram (ECG)

• You Vet will recommend an ECG is an abnormal heart rhythm is detected.

Echocardiogram (with doppler)

• Echocardiography is a two-dimensional ultrasound examination of the heart.
• It allows the scanner to see real-time heart functions and choose which slice to view.
• M-mode and doppler (spectral - with choice to have clour-mapping or not) echocardiography allows measurements to be taken and compared with normal values.
• HCM is usually easily detected using these techniques.
• Echocardiogram HCM scans are usually carried out by Veterinary Cardiologists as they need to be very experienced and skilled to master the technique.

So if I have my cat scanned it will detect HCM for definite?
Remember HCM can occur at any time and that is why annual screening is recommended for breeding cats. A breeder cannot ascertain as to whether they are breeding HCM affected cats without testing annually and even testing retired cats (even if they have moved on). Some breeders will have retirees placed into homes where they are allowed to have the cat scanned at their own expense in order to check the lines they have produced, or kept offspring back from. We ask all owners if we can periodically screen the line at our own expense.

It is also worth noting that an echocardiography is not a perfect procedure for diagnosing HCM, however, it is the best, meaning, most sensitive method currently available for detecting signs of the disease. Auscultation is a less accurate way of detecting the disease in affected cats a significant number of cats with HCM may NOT have an audible heart murmur.

Veterinary Cardiologists recommend that breeding cats should have an annual echocardiogram during their breeding time. The purpose of scanning retired cats is to prevent reproduction of offspring from those placed as breeders or to identify where the problem lies in a line. It can be a very difficult, long-drawn, expensive process. The only way to ensure that the problem is eradicated from the breed is to test and identify where there is a problem.

Kind regards,

Kayleigh McIntosh-Lowrie
Stylisticat UK