Researcher: Possible Connection Between Diet And Canine Heart Disease Is Reversible
by Juliette Goodrich and Molly McCrea
DAVIS (KPIX 5) -- Late last month, the FDA released an update on a troubling trend: a surge in dogs diagnosed with a devastating heart disease who had eaten a certain diet.
The agency named 16 brands of pet food that may be linked to the potentially fatal problem in dogs. These brands were named the most frequently in the cases reported to federal regulators.
Most of the diets reported to the agency are grain-free, or contain certain main ingredients such as peas or lentils.
It's not clear what it is about these diets that may be connected to the issue, but the California researcher who contacted his fellow veterinary specialists as well as federal regulators spoke exclusively to KPIX 5 about this latest report.
"The FDA warning is saying that this is a real issue," remarked veterinary cardiologist and geneticist Dr. Josh Stern of the UC Davis School of Veterinary Medicine.
Stern is pleased with the latest FDA update on dilated cardiomyopathy (DCM) and its potential link to certain diets.
"They went as far to name the diets of concern, which is hugely helpful for the pet owning public to go ahead and try to avoid this problem in their pets," said Stern.
Last year, KPIX 5 introduced viewers to four of Stern's furry patients. All are Golden Retrievers. One of those dogs, named Baker, lives in the East Bay
"He's my buddy, that's who he is. He's like my child," said Baker's owner Sandy Carlevato.
The other three Golden Retrievers -- Suva, Reef and Fiji -- all live near Silicon Valley and are owned by Jamie Warren.
"They're part of my family. I mean, they are my family now," said Warren.
These Golden Retrievers all developed DCM, which can lead to heart failure or even sudden cardiac death. But their diagnoses mystified their owners. The dogs had no history of heart disease.
"He's only five. How could a dog get heart failure?" asked Carlevato.
"It was a mystery. There had to be something else going on," commented Warren.
The dogs had something else in common: they all ate a grain-free diet that contained high levels of peas and lentils. Lab tests revealed some of the dogs also had low levels of taurine in their blood. Taurine is an amino acid that is critical for heart health.
At UC Davis, for the past few years something unusual was going on in the clinic: Dr. Stern and his fellow vets suddenly saw a pretty dramatic surge in DCM.
"This disorder in the past would happen once or twice a year at best. Here, at one of the busiest veterinary schools in the world, and a couple of years ago, we were seeing dozens of a single breed eating very similar dog food and coming down with this disorder," said Stern.
DCM is not commonly associated with Golden Retrievers. The condition is recognized as a genetic condition typically in larger or giant breeds such as Doberman Pinscher, Great Danes or the Irish Wolfhound. It is also seen in Cocker Spaniels, but in these cases, the condition is associated with a taurine deficiency.
Stern alerted the veterinary community to his findings. This lead to the formation of a larger collaboration between multiple institutions and clinicians.
The national team included Drs. Andrea Fascetti and Jennifer Lawson from UC Davis, two of the world's experts in veterinary nutrition and taurine deficiency.
Also from UC Davis, veterinary cardiologist Dr. Joanna Kaplan came on board.
In addition, Dr. Lisa Freeman from Tufts University and Dr. Darcy Adin from North Carolina State University, as well as other specialists, joined forces to investigate and collaborate on what they were seeing at their clinics.
The good news is that Dr. Stern and this team of experts discovered the heart disease in cases where nutrition may have played a role was reversible.
"Low and behold, when we changed their diet and we added supplements to their diet, they got better," noted Stern.
Stern alerted the FDA of his findings. Last July, the FDA began its investigation and solicited pet owners and veterinary practices to be on the lookout for DCM cases.
There is no widespread surveillance system like the CDC has for human health. Stern and the FDA said this level of collaboration was critical to gathering data. And the FDA began to provide updates to the public, the industry and to pet owners.
"They were very forthcoming to put out updates," noted Stern.
In the agency's latest update from June 27, 2019, the FDA reported how the agency has received more than 500 reports of DCM in a wide range of dog breeds that were all ages, sizes and weights.
The FDA and Stern believe these cases are underreported because the condition is typically treated once symptoms appear, and that the diagnostic testing and treatment can be costly and complex for owners.
Among the breeds with the condition most reported to the FDA were Golden Retrievers, Labs, Great Danes, Pit Bulls, German Shepherds, Standard Poodles, Mastiffs, Bulldogs and Shih Tzus.
In the report, the FDA noted that thanks to breed-specific social media groups, owners of Golden Retrievers were motivated to see their vets and get their dogs tested. This type of crowdsourcing could account for the higher numbers of Golden Retrievers reported in the update.
Stern said these social media groups have been invaluable. He saw a grassroots movement among Golden Retriever owners that shared important scientific information to help educate each other. One Silicon Valley owner of Golden Retrievers who had a scientific background commissioned his own lab work and began to collect data and share it within the group.
In addition to the breeds named most, the FDA included a second list of more breeds that had more than one report of heart disease. These breeds include: Afghan Houser, Australian Cattle Dog, Beagle, Belgian Tervuren, Border Collie, Boston Terrier, Bull Terrier, Chihuahua, Dalmatian, English Cocker Spaniel, English Springer Spaniel, Flat-coated Retriever, French Bulldog, Gordon Setter, Irish Setter, Irish Soft-Coated Wheaten Terrier, Jack Russel Terrier, Maltese, Miniature Schnauzer, Old English Sheepdog, Pomeranian, Portuguese Water Dog, Pug, Rhodesian Ridgeback, Rottweiler, Rough-haired Collie, Saluki, Samoyed, Schnauzer, Staffordshire Bull Terrier, Standard Long-haired Dachshund, Vizsla, Whippet and Yorkshire Terrier.
Other data revealed more than 90 percent of the dogs reported ate "grain-free" diets and 93 percent of the foods contained peas and/or lentils as a main ingredient. The FDA defines a main ingredient to be one of the first 10 ingredients listed in a food's ingredient list before the vitamin or mineral ingredient.
As for animal proteins found in the diet? The FDA said so far, no one animal protein source was predominant.
The agency noted how it is not clear what it is about these diets that may be connected to DCM in dogs, writing how "the agency believes that the potential association between diet and DCM in dogs is a complex issue that may involve multiple factors."
At this time, the FDA does not have any definitive information that indicates that any of the pet foods need to be recalled or removed from the market. The agency is not advising pet owners to switch diets. The report offers some advice: if a pet owner is concerned, they should consult their vet and decide what to do next.
Stern is taking a firmer line. He suggests pet owners look at their dog food and see if they contain any of the suspect ingredients as among the main ingredients or a grain-free diet.
"If you are feeding a diet that showed up in the FDA list as most associated with this condition, then you need to think twice about that," said Stern. "My advice to people who are feeding one of those diets that meet any of those criteria is to go talk to their vet and talk about getting their dogs screened for cardiomyopathy. This is a reversible condition that if we catch it early, we can do something about it."
KPIX 5 contacted the companies who were identified on the FDA list. Among those who provided responses were Champion Foods, Midwestern Pet Foods, Zignature and Blue Buffalo.
In their statements, the companies were clear: their mission and upmost priority is to provide safe, high-quality nutrition for pets and that they take the issue seriously.
In general, the statements said there is no causative scientific evidence, even from the FDA's update that directly links their diet, certain ingredients, or any dog's diet to DCM. The FDA called the link "a potential connection."
Blue Buffalo stated the company is actively working with the FDA and the Pet Food Institute to study the issue.
Champion Foods -- which makes Acana and Orijens -- re-launched some of its Acana singles in September 2018 and increased its meat content and added taurine to some diets.
Midwestern Pet Foods, which makes Earthborn Holistic, noted how since they introduced their grain-free products, they've fortified their recipes with taurine, amino acids and L-Carnitine as "prudent nutritional considerations."
Zignature has created a dedicated customer care line to further efforts to fully understand the cardiac issues. The company intends to share any data it collects through its customer care line with the FDA.
One company suggested that the problem is predominately in dogs that are predisposed to DCM, meaning dogs that inherited or were simply born with the problem.
Stern says those comments are unfortunate. In fact, in the FDA's update, the agency noted how many of the case reports included "breeds of dogs not previously known to have a genetic predisposition of the disease."
"We're seeing those companies try to discredit the science and move in the same direction that we saw in the tobacco industry use many decades ago when the link between lung cancer and smoking was first revealed," remarked Stern.
As for Baker, Reef, Suva and Fiji, those Golden Retrievers are almost back to full health.
The FDA is continuing to investigate and gather more information in an effort to identify whether there is a specific dietary link to the development of DCM. The Agency's Center for Veterinary Medicine and the Veterinary Laboratory Investigation and Response Network known as Vet-Lirn are collaborating.
The agency has provided a useful Question and Answers for Consumers link.
Dr. Stern is also continuing his investigation. He is involved in two new studies. One involves Goldens and how they handle certain amino acids that may make them more susceptible to DCM. The second study is a controlled multi-center study that is funded by the American Kennel Club's Health Foundation. This study, which also involves Dr. Freeman and Dr. Adin, will look at DCM and diet in various dog breeds.