Walking by the cardiology department one day last week I (Perry Jameson) observed Dr. Jake Jacobson, our cardiologist, examining a young Sheltie.
About 10 years ago when we had no cardiologist in the Charleston area, I saw most of the heart patients. Remembering back to that time, I recalled that it was rare a Sheltie presented with a cardiac issue, so I asked Dr. Jacobson why he was seeing this little dog.
The dog had presented overnight with trouble breathing and the emergency veterinarian on duty suspected heart failure based on the X-rays. When they awoke Dr. Jacobson overnight to consult, he was skeptical it was heart disease based on the breed, but looking at the films online caused him to change his mind.
Over the course of the night the dog steadily improved while being treated for heart failure. When he first arrived around 10 p.m., his gums were purple unless he was placed in an oxygen cage, but by 8 a.m. when Dr. Jacobson arrived, he was pink and comfortable on room air.
As I watched Dr. Jacobson perform the echocardiogram, we both were surprised to see marked dilation and decreased strength of contraction of the muscles of this dog’s heart. These images were diagnostic for dilated cardiomyopathy (DCM). If this was a Doberman, a boxer or a Cocker spaniel, we would not have been surprised, but this is rarely diagnosed in Shelties.
Dilated cardiomyopathy (DCM) is a condition where the heart muscle weakens, resulting in an enlarged heart. This makes it harder for the heart to pump blood forward, ultimately resulting in heart failure. In most dogs, this causes fluid to accumulate in the lungs, which makes it hard for them to breath and if not treated quickly, they will die.
Since Dr. Jacobson’s primary focus is heart disease, he keeps up with all the recent changes in canine and feline cardiology. Seeing an unusual breed develop dilated cardiomyopathy at an early age triggered him to remember discussions among his cardiology colleagues.
Early this year, cardiologists across the country began to see patients with DCM in unusual breeds. In questioning the parents, many of these pets were found to be eating grain-free or similar diets. This triggered the Food and Drug Administration to issue a public notification in July about the agency’s investigation into the relationship between certain diets and DCM. The investigation is still early, but most of the implicated diets are grain-free and legume-based (such as peas and lentils).
Taurine is an amino acid that is critical for many areas of the body, but especially cardiac muscle. About 30 years ago when the first commercial diets were being made for lower urinary tract disease in cats, taurine was inadvertently left out. Cats, who cannot synthesize their own taurine, started developing DCM and retinal disease. When taurine was supplemented, and then eventually included in the diets, the number of cats with DCM dropped significantly.
Most dogs are able to make taurine on their own, but because Cocker spaniels with DCM respond to taurine supplementation and the history of cats developing DCM with taurine deficiency, this is being considered as a possible cause in dogs. This, however, has not been proven. It may be multiple factors or even how certain components in the diet react together that creates this new condition. The investigation is ongoing.
When Dr. Jacobson questioned the parents about their dog’s diet, he found they had recently switched their dog to a grain-free diet. When asked if this was on the advice of a veterinarian to treat an underlying condition, they said no. The trend of grain-free diets for humans made them feel it was also the best diet for their dog, too. So besides sending him home on the standard heart medications, he also recommended a diet change and taurine supplementation.
Over the next several months, the Sheltie never again had symptoms of heart failure. Repeated echocardiograms revealed the heart muscle gradually improving to the point it was again functioning normally. The cardiac medications were gradually weaned down and eventually stopped with no recurrence of the DCM.
There are certain conditions where feeding a special diet is indicated for pets. Some dogs will develop allergies resulting in itchy skin or diarrhea. These are often related to a reaction to a component in their diet. However, most dogs just need a diet that is formulated to provide all the nutrients they require, not one with special, novel ingredients.
With all the marketing for home-prepared diets, raw diets, vegetarian diets and grain-free diets, combined with our desire to raise our pets as best we can, it can be tempting to try one of these foods.
For many brands, the marketing makes the diet look like one we would want to eat ourselves. If the connection between diet and DCM can be proven, this shows that we have to be careful what we feed our pets. So before switching to a special diet or making your own at home, consult with a veterinarian or veterinary nutritionist to make sure it provides everything your pet needs.
Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to firstname.lastname@example.org.