Hypertrophic cardiomyopathy (HCM)is a health concern in many pure-breed cats. A link has recently been found between Savannah Cats and HCM; some cases indicate that HCM may also be a reoccurring health issue in some wild cats. Several Savannah Breeders have their breeder cats scanned for HCM annually.
What is HCM?
HCM is a disease that can cause sudden death. It causes the thickening of the heart muscle, which results in poor relaxing and filling ability. HCM can be very gradual but can be detected via an ultrasound scan. The pumping chamber, also known as the ventricle, becomes progressively thicker, and less blood enters the chamber. This means that less blood is released into the body.
How is it detected, and what's the cost?
HCM is detectable through an ultrasound scan, which costs between £170 and £300 per cat. However, discounts are often offered for bulk bookings. If you are interested in receiving a discount on your HCM Scans, 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 repeat testing is required to check for the disease. HCM is a known disease in Bengals; 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/kitten's 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 problems with a stethoscope as surgeries are often noisy, cats don't like to sit still, and they are 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 various heart rates. Careful notes will be made if a significant murmur is found, including a grading of 0 - 6. Your cat's 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 to find out 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' hearts checked when they reach one year old by a Veterinary Cardiologist. They will have trained specifically in cardiology and will be more rigorous and specific in their checks than a Veterinarian Surgeon, it can be assumed.
Electrocardiogram (ECG)
Your vet will recommend an ECG if 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 average 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, will it detect HCM for definite? Remember, HCM can occur anytime, so annual screening is recommended for breeding cats. A breeder can only ascertain whether they are breeding HCM-affected cats after testing annually and even testing retired cats (even if they have moved on). Some breeders will have retirees placed into homes where they can have the cat scanned at their own expense 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 echocardiography is not a perfect procedure for diagnosing HCM; however, it is the best, meaning the most sensitive method currently available for detecting signs of the disease. Auscultation is a less accurate way of detecting the disease in affected cats; many cats with HCM may need an audible heart murmur.
Veterinary cardiologists recommend that cats should have an annual echocardiogram during breeding time. Scanning retired cats is to prevent the reproduction of offspring from those placed as breeders or to identify where the problem lies in a line. It can be a challenging, 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.