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Thunder. The Newfoundland Dog With Severe SAS

I’ve been doing a lot of digging through dog medical records over the past month for various reasons, one being Leroy’s medical issues and the other being our recent fundraiser for the Newfoundland Club of America Charitable Trust.

In order to set up that fundraiser I had to go back in time about 21 years so that I could verify to myself the reason why I chose that non-profit.

My first Newfoundland, Thunder, ties into a lot of my passion for the breed. He’s the reason why I’m so interested medical issues that concern the breed because he had a few of them.

I know that I’ve talked about Thunder in the past but here’s the full story of my first Newfie love.

Thunder came to me when he was about 6 months old. Thunder was actually the brother of my first Newfie, Storm. Storm died in a tragic accident when he was 5 months old. I was devastated when I lost Storm and the worst phone call that I’ve had to make to date was when I called the breeder to tell her that Storm died.

I couldn’t even get the words to come out when she answered the phone. The tears wouldn’t stop.

The breeder was just as devastated as I was but she had empathy for me and she did her best to console me.

She didn’t hate me but I knew she was more than disappointed that she entrusted me with one of her babies and this was the outcome.

The next few weeks after Storm died are a blur. I believe that I may have blocked it out because it was such a painful time, but then Thunder entered my life.

Thunder was the only puppy left out of Storm’s litter and the breeder and my sister got together and decided that Thunder should go to me to help mend my broken heart.


The catch was that Thunder was the only puppy left in the litter for a reason.

He had a 5/6 murmur that wasn’t going to go away. He wasn’t meant to go to a family, the breeder was going to keep him because of the murmur.

So when Thunder was offered to me, he was offered to me with the full knowledge that the murmur was there and that it could present a whole lot of problems in his future, if he even had one.

My first instinct was not to take Thunder because my heart was still healing. I didn’t want to replace Storm, I didn’t think I deserved another chance and I most of all didn’t want to have a sick puppy that I knew came with heart-break.

Ultimately Thunder’s fluffy butt won me over and I accepted him through tears.

When the breeder was telling me about him she said, “He’s a hellian.”

Great. Now I have a dog with a bad heart whose a hellian.


We get the dogs that we need right?

So I took Thunder, his bad heart, his mismarked body and his hellianious home with me.

When I say home, I mean HOME.

I was 23 and living on my own with friends at the time but when I got Thunder I made the decision to move back home with my parents in order to provide Thunder with the safest environment possible.

Within the first week that I had Thunder I took him to the vet.

I can’t remember exactly what went down at the vet, if Thunder was diagnosed with SAS at the time, but I do know that our then vet, recommended that we try to get into a new study that was being conducted at The Ohio State University for Newfoundland dogs with SAS. The dog would have to have severe SAS which is what was believed that Thunder had.

Thunder fit the description of what they were looking for in the study so about a month later we headed down to Ohio State.

After a through cardiac evaluation it was determined that Thunder was an excellent candidate for the study.

“The study was to document the progressive nature of SAS in some Newfoundlands during the first year of life. The degree of disease progression is sufficient in some dogs to affect prognosis and therapeutic decisions.”

Thunder’s exam revealed that he had severe subvalvular stenosis; mirtal valve and tricuspid valve dysplasia. He had a 5/6 left basilar murmur that radiated to the left apex. I don’t really know what most of that means but that is what is written on his paperwork.

What is SAS. 

“Subvalvular aortic stenosis, also referred to as subaortic stenosis or SAS, is a common heart defect in dogs, especially Newfoundlands, Golden Retrievers, Rottweilers, and German Shepherds.

The heart anatomically is divided into 4 chambers separated by 4 valves. The 4 heart valves ensure that blood only flows in one direction through the heart. The aortic valve separates the main pumping chamber (left ventricle) from the aorta, a large blood vessel that carries blood from the heart to the body. In dogs with SAS, there is added tissue below the aortic valve (hence “subaortic”). This abnormal tissue creates an obstruction (“stenosis” is the scientific term) that the heart has to overcome to pump blood to the body. This stenosis makes the heart work harder than normal. A heart murmur is created by blood being pumped across the stenosis into the aorta.”

“SAS comes in many grades of severity. They are subdivided into mild, moderate, and severe. Dogs with mild disease usually lead a normal life without complications. Dogs with severe disease may die suddenly or develop exercise intolerance, fainting, rear limb weakness, or fluid in the lungs (heart failure). Heart failure can cause coughing, rapid breathing, or shortness of breath. The course of dogs with moderate disease is hard to predict. All dogs with SAS are predisposed to heart valve infections (endocarditis).”

“SAS is transmitted genetically. This has been studied in the Newfoundland breed; the mode of inheritance in this breed is either autosomal dominant with modifiers or polygenetic. Dogs with mild disease do not necessarily produce dogs with only mild disease, ie a dog with mild disease may sire a litter with severe disease. This defect develops very soon after birth (at approximately 3 weeks of age), and continues to worsen through maturity.”

“Therapeutic options are limited. Surgery can be performed at some Universities, but it is expensive. Balloon catheter dilation can also be performed at some referral centers. This procedure involves passing a catheter with a balloon on the end down an artery in the neck. The balloon is centered across the stenosis and then inflated to open up the stenosis. This procedure helps to decrease the obstruction in some dogs. Medical therapy may be prescribed to try to decrease the work load of the heart (beta-blockers) or treat signs of heart failure once they develop.” –information provided by NCNC.

We were given 3 choices for the trial:

  • Balloon catheter dilation
  • Beta blocker
  • Do nothing

For obvious reasons I opted for the safest route which was the beta blocker.

Thunder was put on 50mg of Atenolol and was weaned up to that dose over a period of time.

We were sent home with a holter monitor to monitor his heart and we would send that back after 3 days of monitoring.

At first, we went to have Thunder evaluated at OSU every 7-8 weeks and then it went to yearly.

I don’t have a date on the paperwork when we started but I believe it was in 1998 and the last evaluation was done in 2002, after the study had been completed.

A total of 22 dogs were in the study and 14 of them were Newfoundlands.

What’s cool was I recently found some data on Newfs that were in that study.

In 1999

Of the 22 patients enrolled, 14 are Newfoundlands. We have 11 dogs on each therapeutic arm of the trial (11 receiving beta blocker and 11 having been ballooned), and we are pleased with the severity matching. Five dogs have died up to this point; three dogs on the beta blocker arm and two dogs on the balloon dialtion arm. Three of the surviving dogs are out over 3 years, 3 are out over two years, and the remaining 11 are all out over 1 year.

Thunder is among the 3 dogs on beta blockers that was still alive at 2 years of age.

Now, we were advised that most likely Thunder wouldn’t live to be past 1 1/2 years and that there was a good chance that he could die from sudden death because he heart was so bad.

This picture, which still hangs in my hallway, shows  Thunder’s personality perfectly. He was anything but a laid back Newfie.


While I never kept Thunder from running there were many times where I would tell him, “Stop running so fast. You’re going to drop over and die one of these times.”

Chasing a ball was one of his favorite things to do and I would hold my breath every time he would run to go get it.

Thunder defied the odds and lived to be 8 1/2. His heart, while defected, never gave out on him.

Around 7 years old Thunder developed Degenerative Myleopathy. It moved fast and it was ultimately what took him from us in 2005.

I realized recently, while searching for things with Leroy’s health conditions, that the DM could very well have been caused from his heart. I never put the 2 things together and no one ever explained it in-depth to me. I guess maybe that’s because they never thought he would live that long to experience it.

This is the reason why I support the Newfoundland Charitable Trust. To help research grants that study health issues affecting our breed. We need these studies to better our breed and to help other Newfoundlands, owners and breeders.




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Anita Perez

Saturday 30th of March 2019

Thank you for sharing your story. Our baby boy (13 weeks) Lumi was diagnosed today with severe SAS. The cardiologist has put him on medication, rather steering us away from the surgical approach. Your story gives us the hope of time for our Lumi. This is a horrendous diagnosis, and time as well as a pain free life is all we can hope for.


Friday 25th of March 2022

@Anita Perez, how is Lumi now? Is he still with you? Our boy, Angus, was diagnosed with severe SAS at 16 weeks after a national expert (Dr. Bright, out of Colorado was in our area) listened to his heart, but later we got an echo to confirm and the vet who did that said it was mild, not severe, and said we'd redo it in a year and it may even go away. He's on beta blockers, and meanwhile, he could live a normal puppy life.

But in the last month, Angus has been getting fatigued sooner, and two days ago after just two runs of fetch (only 20 feet or so), he sat at the far end of the yard, and then fell over - didn't lie down, he FELL, crumpled. Terrifying. He stayed conscious, otherwise I would say he fainted.

Vet (different one than did the echo) says he mustn't run, play fetch, swim...only leashed walks for exercise. He's almost 10 months old.

Today on our walk, just a few minutes in he greeted some neighbors, no jumping, just happy bouncing on his paws, and waggy waggy, and had to lie down before we even moved on from them. And when we got home 20 min later he was still too tired to run after our other little dog after he'd rested. Which is very unusual.

So I think the original diagnosis is more correct. And I'm feeling sad and scared right now.


Sunday 31st of March 2019

I'm so sorry to hear that Anita. Sending all of our love and good thoughts to Lumi!

Tails Around the Ranch

Thursday 28th of June 2018

What an interesting back story on your 'dance with Newfies.' Bless you for letting Thunder fill your loving heart.

My Golden Life

Thursday 28th of June 2018

WOW! That's quite a story! I would say the fact that Thunder lived as long as he did is a testament to your dedication as a "Dog Mom", as well as to the veterinarians you entrusted with his medical care. Just one question: were you a vet tech yet at the time you got first Storm and then Thunder? Or, did Thunder's medical issues inspire you to become one?


Thursday 28th of June 2018

I became a tech towards the latter years with Thunder. It was right before my son was born. And yes, I think Thunder's issues did inspire to pursue that route :)


Wednesday 27th of June 2018

First, thank you for sharing Thunder's story. My daughter's dog Sophi, 4 and a half years old, has SAS as well. My daughter was devastated to learn that she had a severe heart murmur that the vet could feel just by touching her. My daughter opted to go for the $5,000 heart surgery. She takes Sophi every year for an echocardiogram in Maryland. Her half-brother Ben, my boy, had a slight murmur but it went away as Ben got older. My vet tells me Ben is the perfect dog. Right now he has a little bit of a limp because I think he stepped on his foot wrong getting out of the car. I am very thankful to have found your website and I am grateful for Newfie knowledge shared by others. We are first time happy Newfie owners. I hope Leroy is well. Thanks again. Gail

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