There is absolutely no need to worry! Heart murmurs are normal for young dogs and will pass by. Let me quote you VCA's article on Heart Murmurs in Dogs: An innocent or physiologic heart murmur is a heart murmur that has no impact on the dog's health. It is very common for young puppies, to develop an innocent heart murmur while they are growing rapidly. The murmur may first appear at 6-8 weeks of age, and a puppy with an innocent heart murmur will usually outgrow it by about 5-7 months of age. This type of murmur is benign. In the case of a grown-up Frenchie, if s/he is often exhausted and has heavy breathing, you better take him/her to the vet. If s/he has a heart problem, the vet will prescribe some heart medicine. But this case is really rare! NONE of our dogs have ever had any heart issues! If you have any question regarding the health of your TomKings Frenchie, please send it to health@tomkingskennel.com and we’ll forward it to our vet!