This is Piper. You can tell just by looking at her that she is a stunningly beautiful, highly intelligent and incredibly active dog. What you can’t tell is that she is the #1 Doberman Barn Hunter in the known universe. She is just that good. She reached that impressive level a few months ago, at nearly nine years old. What’s more, she is the pride, joy, absolute love and delight of her human owner. Piper is also a Doberman pinscher. When we met her a few years ago, she had a 40% chance of developing dilated cardiomyopathy (DCM), simply because of her breed.
Dilated cardiomyopathy (DCM) is a heartbreaking, fatal disease of the heart, characterized by weakening of the heart muscle and reduced pumping capacity. Like many other age-related diseases of dogs, it is diagnosed in humans as well. As in humans, the symptoms include reduced activity, shortness of breath, and irregular heart rhythms. Over a relatively short period of time, the heart becomes enlarged and strained, eventually leading to congestive heart failure. As the heart fails, dogs have an increasingly difficult time resting and eating.
The exact cause of DCM is not known, but there is a definite genetic factor involved in both humans and in dogs. DCM is also an age-associated disease, with risk increasing as dogs get older. Certain larger breeds are much more susceptible to DCM, including Doberman Pinschers, Irish Wolfhounds, Great Danes, Saint Bernards and Cocker Spaniels in particular.
Treatment for DCM involves the use of drugs to improve heart performance and is specific to the individual dog and the stage of their disease. While drugs can slow the development of the disease, DCM is a progressive disease. Once diagnosed, a dog’s health and attitude will be monitored closely for the remainder of his or her life. Dogs with DCM generally do not live more than two years after diagnosis.
Stem cell treatment and gene therapy may one day be an option for treating DCM in dogs, but presently there is no cure. One of the goals of the Dog Aging Project is to address this urgent need. Research in mouse models suggests that rapamycin can reverse the progression of this frustrating, tragic disease. Our goal is to determine if, as suggested in mouse models, rapamycin can be used to treat DCM in companion dogs.
Piper was 7 years old when she entered our first clinical trial of rapamycin and showed no signs of DCM. By a random process, she was assigned to the treatment group and given 0.1 mg/kg of rapamycin three times each week over a 10 week period. Just those ten weeks resulted in improved cardiac function, specifically from 19% to 27% fractional shortening and from 46% to 61% in ejection fraction. Six months after our study concluded and she had stopped receiving rapamycin, her heart function declined again and a diagnosis of occult dilated cardiomyopathy was made for her. Treatment with pimobendan was recommended by an independent cardiologist. Piper does not seem to know any of this just yet.
Although based on data from a single dog, Piper’s story suggests that rapamycin treatment may have had a profound beneficial impact on heart function. One goal of the Dog Aging Project is to determine whether treatment with rapamycin at a safe, well-tolerated dose can delay or reverse progression of dilated cardiomyopathy in companion dogs at high risk of developing the disease. We would love to be able to help Piper. We would love to make a difference in her life, as she had made one in ours. Time and funding is not on our side, but we will continue in the hopes of making a significant difference in the lives of other large-breed dogs. Our goal is to generate funding for a study specifically addressing DCM in dogs. To do it as soon as humanly possible.
Remember that DCM is significantly more common in large-breed and giant-breed dogs. It is relatively rare in small breeds. If you do not know if your dog is at risk, ask your veterinarian. If your dog is at risk, be sure to do all of the following:
- Get regular checkups
- Be aware of changes in energy levels and zest for life
- Maintain a consistent exercise program
- Follow a healthy diet
- Appreciate every single day you have with your four-legged friend
Lastly, if you would like to help us help dogs, please consider making a donation to the Dog Aging Project. Your donations are tax-deductable and 100% goes to research. 100%, as in all of it.
by Tammi Kaeberlein
Photos by Patricia Larkin