Dog foods reported to be associated with the disease are often labelled "grain-free" and usually contain certain ingredients, including peas and potatoes, which are used to replace other ingredients such as rice or corn.
Peas are at the top of the list of ingredients linked with compounds that might be related to DCM.
Legumes and pulses have been used in pet foods for many years, which has led scientists to suspect it may be an issue of quantity.
Since the FDA began warning dog owners in 2014 that heart failure in their dogs might be associated with some types of food, more than 1100 cases of diagnosed DCM have been reported to the agency. At least 280 of the dogs died.
The FDA is not recommending a recall related to heart disease or declared any specific products unsafe.
"I see this as a piece of the puzzle," said Dr Lisa Freeman, a professor and veterinary nutritionist at the Cummings School of Veterinary Medicine at Tufts University.
"This research helps us narrow down the targets to look at so we can focus on the most likely causes and get to an answer more quickly."
Dr Freeman said she is not yet advising owners to steer away from all foods containing peas.
"Until we know the exact cause, we want to be cautious of all the ingredients the FDA is investigating," she said.
The Kennel Club advises owners that some fruits and vegetables are in fact poisonous for canines. "Onions, garlic, leeks, shallots and chives all belong to the allium family. These plants all contain a substance that can damage red blood cells in dogs and can cause life-threatening anaemia," it said.
- Telegraph Media Group