Heart Murmurs in Large Breed Puppies

[GuyMann89]

Hi everyone,

This coming weekend I will be picking up my first fur baby! My family has owned plenty of dogs, but this one will be the first I am raising on my own. I picked my fur baby out of the littler when it was born and now that he is 8 weeks old he's ready to come home.

The breeder and I have kept in contact and during his vet checkup it was discovered he has a grade 3 heart murmur. The breeder and her vet don't seem concerned about it and told me it is not uncommon for large breed puppies to develop heart murmurs as their cardiovascular system grows and that the murmur generally goes away when the puppy is 4-6 months. I researched this and it seems to jive with the information on reputable websites.

Don't get me wrong. I am committed to this little guy through thick and thin and nothing would make me give him up. I realize the best thing to do right off the bat is to monitor the murmur via periodic checkups with my veterinarian. I'm just a "hope for the best, prepare for the worst" kind of person. I have no experience I can relate to this situation and was hoping to get input (and hopefully ease of mind) from all of you if you (or someone you know) has dealt with this in the past or is currently going through it.

In case it's relevant, both parents are currently in good health. I haven't gone into detail about the parents' medical history yet, however, the breeder is reputable and I trust she wouldn't breed dogs that have diagnosed and/or genetic medical issues. The breed of the parents and puppy is German Shepherd.

Thank you all for your input.
-GM-

 

[Humpy]

You should take your dog to a veterinarian cardiologist who should perform an ultrasound diagnostic on the heart. Do it when the dog is about 18 months old. But don't just go to a regular vet who does ultrasound, it should be a proper cardiologist.

 

[caikgoch]

Start with a large vet college like TAMU. My aunt got open heart surgery on a dustmop there.

 

[1000extra]

Grade III heart murmurs generally indicate a more severe heart issue in large breed dogs and it may not go away. In general, I would be less concerned with a grade I heart murmur as they tend to improve/go away when the puppy gets older and their heart matures.
I pick up grade I heart murmurs in 8-10 week old puppies commonly and I always tell owners to keep monitoring that low-grade murmur regularly. Make sure that it doesn't progress, get worse/louder or cause any abnormal clinical signs.

For higher grade heart murmurs:
1. Not uncommon for some large breed puppies to have pulmonic sternosis (narrowing of the base of the large blood vessel located in the exit point of the heart to the circulation of the lungs). It restricts smooth blood flow from the heart and causes turbulent flow and swishing of blood within the blood vessel).
2. Might also be a patent ductus arteriosus (PDA), which is failure of closure of a vessel that connects the aorta to the pulmonary vein in unborn puppies. This causes mixing of oxygenated and deoxygenated blood within those vessels and causing continuous blood swishing.
3. It might also be an atrial/ventricular septal defect (Hole-in-the-heart) that causes mixing and swishing of oxygenated/deoxygenated blood within the heart itself.

Pulmonic sternosis and PDAs are treatable surgically. ASDs and VSDs are possibly treatable depending on the size of the hole.

The best way to find out if your puppy has an abnormal heart condition is having a veterinary cardiologist listen to his/her heart and possibly perform an echocardiography(Heart scan with an ultrasound) to determine the source of the murmur.