HCM in Ragdoll Cats
The other day a Floppycats reader emailed me concerned that her kitten might have HCM, I did not have a good idea of what all it entailed. So I reached out to Lorie Huston, DVM to see if she could provide insight for us. Thank you to Lorie Huston, DVM for writing this – please feel free to ask questions!
Guest Post by Lorie Huston, DVM
Hypertrophic cardiomyopathy, or HCM, is the most common form of heart disease seen in cats. In Ragdolls, most cases of HCM are inherited from the parents and caused by a gene mutation. Fortunately, we have DNA tests that can detect if a specific cat is carrying the mutation. Unfortunately, we don’t have a cure for HCM at this time, although medications are available that may help some cats.
Affected Ragdoll cats may inherit a mutated gene from just one parent (which is referred to a heterozygous) or a mutated gene from both parents (referred to as homozygous.) In Ragdolls, cats that are heterozygous tend to have a milder form of the disease than those that are homozygous although the disease can still be very serious even in heterozygous cats. (This varies in other cat breeds as the specific mutation and the means of inheritance varies from breed to breed.)
Hypertrophic cardiomyopathy affects the heart muscle, causing the muscle to become thickened, resulting in an inability to pump blood normally through the heart. In most cases, the left side of the heart is the most severely affected, leading to left-sided heart failure.
Symptoms associated with HCM include:
- Difficult breathing.
- Increased respiratory rate.
- Increased respiratory effort.
- Increased heart rate.
- Weakness.
- Lack of appetite.
- Lethargy.
- An irregular heart rate (arrhythmia) which may cause fainting episodes.
- Cyanosis due to lack of oxygen.
- Hind leg paralysis and/or pain due to a blood clot lodged in the aorta (aortic thromboembolism). In this situation, a blood clot breaks off from within the heart and travels through the aorta, becoming lodged at the end of the aorta blocking the flow of blood to the hind legs.
DNA testing can reveal whether your cat carries the gene mutation most commonly responsible for HCM. However, the only way to accurately evaluate how your cat’s heart is functioning is via an echocardiogram. Though the inherited heart disease caused by the gene mutation is the most common cause of HCM in Ragdolls, there are other causes as well. For instance, hyperthyroidism has been implicated in causing toxic changes within the heart that may cause cardiomyopathy. (Some cardiologists argue that these cases are not accurately referred to as hypertrophic cardiomyopathy but the symptoms are still similar.)
An echocardiogram is an ultrasonographic evaluation of your cat’s heart and allows direct visualization of the heart muscle and individual chambers of your cat’s heart. A cardiologist can measure the muscle thickness and determine whether your cat’s heart is pumping blood through its various chambers effectively and efficiently.
Most cats with cardiomyopathy will need to have an echocardiogram performed on a periodic basis to monitor progress of the disease.
There are a number of drugs that are used to HCM.
- Furosemide (Lasix) is a diuretic and is used to treat congestive heart failure by removing excess fluid accumulating in the lungs and other body tissues because of the heart failure. Another diuretic less commonly used is spironolactone.
- Enalapril and benazepril are ACE inhibitors (angiotensin-converting enzyme inhibitors). These drugs help HCM cats by causing vasodilation, or opening of the blood vessels, making it easier for the heart to pump blood.
- Pimobendan (Vetmedin) is a drug that causes both vasodilation and an inotropic effect which causes the heart muscle to contract with a greater force.
- Anticoagulants are often used in an attempt to prevent or control blood clots. Aspirin and clopidogrel (Plavix) are the two most commonly used anticoagulants.
- Cats with HCM may have elevated blood pressure also. Medications which lower blood pressure may be necessary and include amlodipine and atenolol.
- Supplements such as taurine, L-carnitine and coQ10 are sometimes used as well but their effectiveness is questionable.
Thanks again to Lorie for helping us understand HCM in Ragdoll cats! Please join Lorie on her website – Pet Health Care Gazette
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About the Author (Author Profile)
Hi, I’m Jenny Dean, creator of Floppycats! Ever since my Aunt got the first Ragdoll cat in our family, I have loved the breed. Inspired by my childhood Ragdoll cat, Rags, I created Floppycats to connect, share and inspire other Ragdoll cat lovers around the world,Subscribe
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Hi, I’m Jenny Dean, creator of Floppycats! Ever since my Aunt got the first Ragdoll cat in our family, I have loved the breed. Inspired by my childhood Ragdoll cat,
As someone who lost a kitty to HCM about a year ago, I am painfully aware of the symptoms and treatments available. I used Lasix, Enalipril and VetMedin (which is normally a canine drug) over an agonizing three month period. The costs of the drugs weren’t the problem – it was having the fluid drained around the lungs and all the diagnostic tests that ran the bill into the thousands. From a strictly unemotional perspective it wasn’t worth it, but I found that I just couldn’t let him go without trying something.
In hindsight I question whether I held on too long, but since I’d only had him for three years (he was a stray who showed up on my front door step) I was devastated by the thought of losing him. I’ve lost cats who died of age-related issues, but over a span of years it gets easier to accept. Not easy mind you, but I’ve been lucky to have cats that lived near two decades in most cases.
So if you have a kitty that is diagnosed with HCM, just be realistic on the expected outcome. Be sensitive not only to your own feelings, but also those of your suffering pet. I hope nobody else here gets a diagnosis of HCM for their cats, and I’m just glad my newest Ragdoll was found HCM-negative as a kitten.
This is probably a very stupid question but if both parents test negative for HCM, is there any way the kitten could get this?
Janet…..not a stupid question AT ALL!!!!! My six month old male kitten, who did NOT have a heart murmur or any signs of distress, DIED in recovery at six months old, after being neutered. It was shocking and very, very sad. I saw the paperwork where both parents tested “normal/normal” for HCM. My vet did a necropsy to confirm cause of death. I will be taking my other two kittens to Auburn Vet School Cardiologist Specialist before I have the youngest one neutered. The other kitten that was being neutered at the same time, did not have any complications…..they had different mothers, but the same father. The vet said it may have skipped a generation or just been a fluke. I was devastated.
That is just awful. I am so sorry to hear this. I can’t imagine how devastated you must have been. I am now wondering why I want to get a Ragdoll at all if they are this fragile! Are they really this fragile? I am on a waiting list for a kitten that is from a breeder in Sacramento who seems very good and diligent and tests her cats for HCM and feline leukemia. I am really interested in who your breeder is as I looked at a couple in Auburn and stayed away from one. Would you mind telling me? if not on this site, you can email me at knowltons4@att.net. I have had cats (humane society rescues) all my life and never dealt with these kinds of problems…just the typical old age. I also am learning about all the horrible breeders out there that do not test at all and sell sick kittens and then they later die. These people should be sit down…but that’s another story.
sorry “shut down” not sit down!
Testing for HCM does not prevent it!! We test for one gene in Ragdolls. There are over 100 genes in people which are responsible for HCM. Anyone who tells you it cannot happen is either not educated about the disease or not being honest. Please educate yourself instead of blaming the breeder. Light blue-eyed males of ANY cat species are more likely to suffer from HCM, we don’t know why, but may be gene linked. It is not usual to see symptoms before the death occurs, but you may. The necrotopsy of a cat who died from HCM looks very similar to the necrotopsy of a cat who suffered an anesthetic accident. This lets vets off the hook with a very convenient excuse. Ragdolls are not “fragile.” We just happen to be one the groups more active in testing. ALL cats are susetible to the disease. Persians, Maine Coone and Ragdolls run a higher incidence in the pedigree population. No one is looking for it in the domestic short hair population!
I was only pointing out the breeders that do no testing at all. Thank you for all the information…not that it makes me feel any better! Just like anything else, the horror stories are the ones that are generally posted and not all the great stories. I have to keep that in mind.
I am planning n getting a ragdoll kitten and i have just recently heard about this disease in the ragdoll breed. If the breeder that i am planning to get my kitten from does not test for this problem is that a red flag should i take myself of the waiting list or could I get him tested myself? Also do you test the parents & the kitten for this disease or just the parents, how often should your kitten be checked? When these tests are done should papers be provide to the person adopting the kitten (me) for proof that the kitten and parents are HCM free? Sorry for the overwhelming amount of questions just want to be sure my breeder is reliable & my new kitten will live a long healthy life.
All I know is that a responsible and reputable breeder should absolutely be testing for HCM and feline leukemia and a couple others. No exceptions. I am with you…I am a nervous wreck now after reading all these horrible stories. I’ll let the more experienced Ragdoll owners answer the rest. Check out some of the complaints and it is shocking. I would like to know the answer to your questions too.
I am not a musician and I don’t play one on TV (a bad Jackson Galaxy reference), but I would be VERY surprised if a six-month old kitten could die of HCM while being neutered. As someone else alluded to earlier, I’d be more suspicious of how anesthesia was administered as well as if there was post-surgery monitoring. Animals are just as susceptible to allergic reactions to medicine, so if possible a pet owner should insist upon observation during recovery.
As for HCM screening, I’m sure there is no 100% certainty. Much like a DNA test can be taken that will show a human’s predisposition towards certain types of cancer, there are other factors such as environment and nutrition that can play a factor.
I would hate to think someone would pass up the joy of a Ragdoll’s company for fear of what might happen. Nothing is guaranteed, and the love and contentment of holding my big boy “Panda” more than makes up for the risks.
You are absolutely right!