Why is my dog losing weight with a fast heart and a hissing sound?

These symptoms are probably not connected to the heart murmur, it's more likely to be due to pain, possibly as a result of a gastrointestinal problem. Keep him rested and if he is still the same by tomorrow take him to the vet to get treated.

You should get your dog seen by our veterinarian right away. Rapid heartbeat in dogs could indicate that he is in pain, has heat disease, an electrolyte imbalance or another hidden condition. Left untreated it can lead to injury of the heart itself and/or congestive heart failure. Your vet will do an exam, blood work and x-rays to determine the cause of the illness and suggest an effective treatment plan.

I am mostly concerned about the weight loss, lethargy (depression) and the labored breathing. This is certainly not normal for such a young dog. From the symptoms you are describing, a metabolic disorder seems most likely. Options are hyperadrenosorticism (Cushings), hypothyroidism (although this is not consistent with the weight loss), certain sex hormone disorders, and certain immune mediated disorders. Since this has been going on for such a long time, I would advise a consultation with a specialist at this point. You can find a veterinary internist in your area on www.acvim.org.

It sounds like her heart is struggling to beat properly or having to work very hard to get blood around the body. What you are hearing could be a murmur or arrhythmia. I would take her to the vet now to have this checked out, it is not good if you can noticeably hear an issue with the heart without a stethescope. Try and keep her calm and go to the vet asap.

Heart disease is tough. This is true for humans or animals. Pets can quickly go from ok to not ok in minutes. Most forms of heart disease are progressive which means they get worse over time. Signs of worsening heart disease can be increased heart rate and respiratory rate, collapse, exercise intolerance, or coughing. There are many medications that can help improve quality of life. Please see your vet ASAP for an exam and possibly more tests or meds. Hope Boomer feels better!

She may have intestinal parasites or not get enough or proper puppy food. Trouble breathing and weight loss can also point to congenital heart disease or a liver shunt. You need to take your dog to a vet for an exam and worming.

Depending on the underlying cause, a murmur may intensify quickly. A murmur is an abnormal heart sound, it is not an accurate indicator of heart function. To accurately evaluate cardiac function, you would need to have an echocardiogram (ultrasound of the heart) performed on Muff. Your veterinarian may do this or may refer you to a veterinary cardiologist.