Can a heart problem in my cat be made worse by giving steroids?

Can an undetected heart problem in my cat be made worse by giving steroids?

Symptoms: lethargy and loss of appetite.

Editor's note: If your cat is exhibiting these symptoms, please call your vet and get some guidance.

Steroids are powerful drugs and not without side effects. I have heard of steroid use causing a reaction in cats that have heart problems.

Lethargy and loss of appetite can be some of the symptoms. In some cases, congestive heart failure can result, which needs immediate treatment.

Some cats, sometimes very young cats, have underlying heart problems but show no symptoms.

Other cats don't develop signs of heart problems until later in life. This was the case with my cat, Priscilla, who was diagnosed with hypertrophic cardiomyopathy at age 11.

Since echocardiograms aren't done unless either the cat shows symptoms, or a veterinarian detects a heart murmur (that's how Priscilla was diagnosed with HCM), there's no way to know that anything is wrong beforehand.

See Dr. Vicky Lamb's response to a cat parent with a 1 year old cat with an apparent reaction to a steroid shot.

"The reaction that your cat had to the shot is one we can see in cats that have underlying heart disease. The steroid shot did not cause the disease, it just made it evident to us by the side effects it causes. So, most likely, your cat had a diseased heart already, that was functioning pretty well prior to the shot. The shot then made his heart worse. Most cats will experience lethargy from the steroid shot for 24 hrs. However, if there is difficulty breathing or the lethargy does not resolve, I will start worrying about the heart. There are some cats whose hearts will sound completely normal on examination, but will have a bad reaction to the steroid shot, and there is no way to predict this unfortunately. These cats usually have hypertrophic cardiomyopathy."

Also see Dr. Elyse Kent on whether or not steroid use is dangerous in cats.

"A less common side effect of corticosteroid use is to uncover hidden congestive heart failure (CHF). If heart disease is undetected (occult), especially if a heart murmur is not heard, fluid can rapidly fill up the lungs causing labored breathing and distress after a steroid injection is given. If the patient is promptly seen by a vet on an emergency basis and CHF is diagnosed by a chest x-ray, oxygen therapy and diuretic injections generally cause the fluid to be urinated out and an echocardiogram can be performed to further define the heart condition."

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Feb 26, 2017
Steroids CAN cause heart failure
by: Tara

My veterinarian put my cat Sunny on Prednisolone last year in order to help with the itching caused by her allergies. It helped for that, but within a couple of months, Sunny started having problems breathing. So bad that I had to rush her to the emergency room one night. Tests were done and not only was she found to have a heart disease called Cardiomyopathy-- which I was told is common in older cats-- but fluid had built up all around her heart. They had to use a needle to draw the fluid out. The emergency vet said that it didn't make sense why Sunny had gotten the fluid because her Cardiomyopathy wasn't that bad. When he found out she'd been on Prednisolone, he said THAT was the cause.. He said cats with heart disease should never be given steroids because they cause the heart disease to worsen into heart failure. The problem is, I didnt know and my vet didn't know, that Sunny even had heart disease when she put her on the steroids. She had no symptoms of anything being wrong with her heart until the Prednisolone caused her to go into heart failure. She's all right now, but never again would I ever allow any of my cats to be put on steroids for any reason. They're dangerous.

Feb 25, 2017
Steroids don't cause heart failure
by: Anonymous

When debating whether or not to allow steroid treatment, remember (As the article stated) that steroids do not *cause* or "give" heart failure or heart issues.

Rather, the steroid can cause a pre-existing heart condition to show itself, as a poorly working heart will not respond well to the steroid.

There is a difference and it's important to keep in mind when considering the options. If a cat isn't showing ANY sign of heart failure or heart condition there is little reason to suspect steroids will be problematic.

Feb 11, 2017
My Cat Too
by: Anonymous

I know for a fact that steroids caused my cat to get congestive heart failure because his cardiologist told me so.

Little Guy was prescribed Prednisolone by his regular vet in 2015. He was 14 at the time and had suffered from chronic respiratory infections his entire life. Supposedly, the Prednisolone would help make his infections occur less frequently and be milder in nature. From the beginning, I was worried about the bad side effects I knew steroids could cause. But my vet just kept telling me that , quote " we have to weigh the benefits against the risks".

However, the Prednisolone did very little to help my cat's respiratory infections and after a year of being on them, I told my vet I wanted him off them. But it was too late. Unbeknownst to anyone (because he had no heart murmur to give it away) Little Guy had Hypertrophic Cardiomyopathy. I found out the day I had to rush him to the emergency animal hospital due to sudden collapsing episodes. The steroids had caused his pre-existing heart disease to develop into a pleural effusion.

Little Guy survived but the heart medications he had to be on every day thereafter did a number on his kidneys and I had to put him to sleep on February 1st, 2017.

Don't let your vet put your cat on steroids without knowing the condition of his/her heart beforehand. Again, I have the word of a board-certified veterinary cardiologist that steroids can indeed cause heart failure in cats.

Jan 03, 2017
Tragic losses
by: Kurt (Admin)

I'm sorry to hear about everyone's cats having so many problems with steroids, and tragic deaths and illnesses.

Unfortunately, we have to rely on our veterinarians to guide us. There are cases where that guidance seems to be lacking. In some cases, I'm hearing people say they weren't informed of the dangers. In other cases, I'm hearing denial of a connection with steroids and deaths or illness in the cats.

I think all we can do to help protect our cats is ask more questions, and try to stay as informed as possible. If your cat has a heart problem, it's even more important to ask questions before any treatment is given.

Even then, we can't be sure we're making the right decision. Being a cat parent isn't easy.

Jan 03, 2017
Can a steroid kill my cat with a heart murmur?
by: Anonymous

My Bette would be 3 in April of this year I already knew she had a heart murmur when I took her in to be spayed a year ago. This past Summer we had a terrible problem with fleas and Bette being a long haired cat seemed to wrestle the most with constant scratching and biting leaving many scabs around her neck and above her tail. Last Wednesday I took her to the vet to possible help her with the scabs. The first thing he noticed was the heart murmur then he proceeded to give her another rabies shot a distemper and finally a shot of steroids which he stated would help with the scabs and itching. 2 days later in the morning she ate as usual and seemed very much her self the itching seemed to be a little less but when we left in the morning I noticed her breathing seemed shallow but not uncommon with her. We come home 6 hours late and she is foaming at the mouth and rigor mortis had already set in, could she have been allergic to the steroid? she wasn't even 3? heartbroken I also have her sister which has a murmur as well now I'm terrified something will happen to her.

Nov 10, 2016
Be Extremely
by: Anonymous

My old cat had a steroid injection on Thursday of last week and was dead by Saturday morning. The vet, naturally, said that the injection would have had nothing to do with her death. I don't agree.

Oct 22, 2016
Reply to Karen M.
by: Paula C

Karen M,

I wish I was told to bring in my cat after 10 days on steroids..then they would have seen her heart was worsening..our cat also had small cell lymphoma.. I wish you all the best ..hope there's an alternative treatment you can use..maybe even something holistic.

Oct 22, 2016
Gave cat steroids and he got Congestive Heart Failure
by: Karen M

We give our cat steroids as a last ditch treatment for suspected pancreatitis. Ten days later took him to get ultrasound and found congestive heart failure due to steroids. Immediately started him on diuretic and we will see cardiologist again 3 weeks to see if fluid has drained away. Cat is extremely hungry, has diarrhea. Vet now say it's small cell lymphoma (not uncommon in old cats, he's 15). Problem is the treatment for that is oral chemo and Steroids! We will go to vet in two weeks to see what alternatives there are to that treatment. If we'd given him that treatment before we wouldn't have seen the CHF in time and he likely wouldn't have survived. We are hopeful, and spoiling him daily of course. Fortunately,I'm home with him all the time.

Sep 13, 2016
Steroids and Heart Murmur
by: Anonymous

I absolutely agree with Fiona's mom! My cat was prescribed prednisone ..she had a heart murmur ..she tolerated it for a short time.. but then she stopped eating and drinking and was stumbling..we brought her to the vet..they said her heart murmur worsened and she developed diabetes (all from the prednisone!)..she passed away the next day..I think about her everyday and my heart breaks because I thought I was helping her by giving her the prednisone.

May 25, 2016
do not give cats steroids
by: Anonymous

It absolutely can. I searched this to let you know. My cat Fiona has had a heart murmur ever since she was a baby. The vet have her steroids today to see if it would help her heavy breathing and not 2 hours later, she died. Do not let your vet give your cat steroids if they can't absolutely confirm your pet doesn't have any heart problems. RIP my lovely kitten

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