HCM in Ragdoll Cats

HCM in Ragdoll Cats

A reader wrote in telling me her kitty suddenly passed of HCM.  She has asked that I re-run this guest post by Lorie Huston – may she RIP.


Originally published Jul 26, 2012

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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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,

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  1. Lynn Nelson says:

    If I were to purchase a kitten would you recommend I get an electrocardiogram right away to determine it didn’t have HCM?

  2. Nancy Colson says:

    Does anyone know what percentage of Ragdolls end up with HCM and how those numbers differ between those who test positive or negative for the gene.

  3. Karen Jones says:

    My first experience with a Ragdoll ended in tragedy but didn’t stop me from getting my next one. I ended up being “saved” by my first one Missy a stray that had been abandoned and I didn’t even know she was at least part Ragdoll at the time. I had her for a little over 8 years. She was 9 when she died suddenly. She had never been sick a day in her life and always had good check ups at the vet except she was a little overweight. She stopped eating and got really lethargic. I took her to the vets, from their we went to the emergency clinic where they could provide 24 hour care. She was there for 4 days, they called and said she was better and I could come get her. In the 40 minute drive it took to get there, something happened. As I waited in the lobby, wondering why they wouldn’t just simply give me my baby, they finally came and got me and said she had a medical emergency and her heart had stopped and lungs had stopped they brought her back and they asked what me what I wanted them to do. I yelled fix her! They tried, but unfortunately they could not keep her lungs or heart going (I don’t remember which one). Turns out she had HCM. I had never heard of it before. I got my next kitty, a kitten from an excellent breeder who said both parents were negative for the gene. I did a lot of reading and I talked to my vet, who also did a lot of reading, and I STILL had Isabella tested just in case. It was $110 for some piece of mind. And if she had tested positive then I would know in advance if she needed any preventative type of care. Better than not knowing at all and being blindsided!

    1. I assume my vet will know about the gene test – do you think so too? Or how do I ask for it?

      And I am so sorry about your Missy.

  4. Sheila McRae says:

    I lost my 7-1/2 year old ragdoll boy, Rocky, to HCM nearly 3 months ago. He was diagnosed when he had congestive heart failure last November. His sides were heaving because he had so much fluid in his lungs. A 48 hr stay in an oxygen tent and diuretics enabled him to come home where we administered medication to him daily. The nearest cat cardiologist is 250 miles away, so we did palliative care. In early February, we lost him at home. There wasn’t anything different that alerted me that this was the day that he was going to pass. It is a devastating disease but I’m comforted to know that he doesn’t have to suffer any longer. My heart has a “Rocky-shaped” hole that I’m reminded of on a daily basis. It’s my hope that the grief will fade someday.

  5. Teresa Reid says:

    Oh my goodness, am so very sorry for your loss and that now you are having to go through it again with your sweet Annie too. That is just heartbreaking beyond words. She is very blessed to have such a loving, caring parent by her side who will ensure everything possible is done to make her happy and comfortable. The knowledge you gained having gone through this with your other little kitty will be of great benefit to your Annie because you are familiar with the meds and their effects, etc. Again, am so very sorry Annie and you have to go through this. Sending you love and hugs. ♥♥♥

  6. Patti Johnson says:

    Great and very helpful re-post, Jenny. I am so sorry to hear that a fellow Floppycatter has suffered such a tragic loss. My heart and sympathies go out to her and her family. RIP Sweet Kitteh. <3

    Big hugs!

    Patti & Miss Pink Sugarbelle 🙂 <3

  7. I have tremendous empathy for each of you who have a sick kitty with HCM or have lost one. My beautiful and incredibly sweet Annie (Ragdoll of the week, December 29, 2014) was diagnosed with HCM about three months ago, at seven years of age. It took close to five months and several vet specialists before a definitive diagnosis could be made. Initial symptoms were elusive, slight lethargy, some loss of appetite, and trouble going up the stairs. The symptoms baffled her vet, who referred her to a feline internist, who suspected HCM, and referred us to a veterinary cardiologist who finally made the diagnosis.

    Having lost another pet to HCM, I am terribly sad, knowing the awful toll this disease takes both on the fureperson and his/her family. It is devastating to watch–helpless–as the disease progresses. And having to make the decision of when the kitty’s decline is severe enough so that her suffering may be averted is heartbreaking. It is fortunate if the kitty can tolerate the medications to improve symptoms, but some kitties cannot. In Annie’s case, the ACE inhibitor and Plavix caused severe diarrhea and vomiting. Also, sometimes Lasix seems to be better tolerated if several smaller doses are administered more frequently (half a dose twice a day, for example), than giving the entire dose once a day.

    Going forward, I can only take care of Annie the best I can, and of course love her, adore her, and insure her every comfort until the awful day when we have to say good-bye. I know her brother George (who is a flame point, and does not carry the HCM gene) will miss her terribly as well.

    1. Patti Johnson says:

      I am so very sorry that your Sweet Annie girl has been diagnosed with HCM. You must be devasted (especially since you’ve been through the nightmare of HCM already with a previous, beloved pet)! *BIG LOVING HUGS*

      Sending you prayers of strength and guidance and asking for a miracle that will allow Annie to have many more years of a good quality life filled with love and care with you.

      Big hugs (again)!

      Patti & Miss Pink Sugarbelle 🙂 <3

    2. Amason,

      I am so sorry to hear about Annie, my heart goes out to you. I got a scare from the vet earlier this week and I don’t know what to do. Cynthia “Symph,” is my first pet. I got her when I was in Law School (2012) . From the first day, she has lighted up my life with her personality. After I graduated and passed the bar, I fell into a deep depression. I do not know what how low I would have went had I not had her to think about. The thought of someone else taking care of her or playing “our” games with her was motivation to get me out of bed in the mornings. In a way, she become an emotional support animal. I’ve worked a’lot from home since Law School, so we spend a’lot of time together. Everyday she sleeps next to me in her desk chair while I work from mine.
      She is the most loyal best friend. Anyways she has had a persistent cough since around November. I brought her in to see the vet several time and it was always attributed to allergies. We even took some x-rays. I switched vets about two months ago so we could get to the bottom of this. He brought up HCM last visit. I’ve been pretty upset about it, and wanted to connect with anyone who has experienced the same thing.

      1. Sorry to hear about your depression. I hope you can get on the other side of it – I have known depression well and it’s awful. There might be more people on our Facebook page that have experience with HCM or other types of coughing – we could always ask? Please just shoot me an email about what she does, and we can ask about it.

  8. Our first beautiful Ragdoll was an alley kitten, rescued and given to my daughter by her friend. He appeared to be in good health but died suddenly at age 10. Gizmo had been racing around the house, playing with our other cats. When I went to bed he wasn’t waiting there for me on the pillow as usual. I found him lying in another favorite place and he seemed to have passed away peacefully in his sleep. The vet said it was probably a heart attack. At that time (early 1990s), I wasn’t aware of HCM, but I think it may have caused Gizmo’s death.

    Later I found another gorgeous rescue Ragdoll. We had many happy years with Moosie until he died from an different issue, a large mass in his abdomen which was inoperable and probably cancer.

    We loved our Ragdoll boys very much and hope someday to have a Ragdoll – or two – again.

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