Feeding your dog peas could lead to canine heart disease, study finds

Feeding your dog the remains of your dinner can seem like a harmless thing to do, but a new study warns peas could increase their risk of getting heart disease. 

Scientists in Massachusetts have found a link between canine consumption of peas and the development of canine dilated cardiomyopathy (DCM) – an often fatal condition that causes a dog’s heart muscle to enlarge.

As the heart dilates and becomes larger, it becomes harder to pump, which can lead to heart valve leaks or a build-up of fluids in the chest. 

Worrying, peas and other legumes including lentils and chickpeas have been ingredients in some ‘grain-free’ dog foods for years – and could be responsible for hundreds of dog deaths. 

‘Grain-free’ dog foods containing legumes instead of grain have already been investigated by the US Food and Drug Administration (FDA).

Although the scientists have now revealed a link between canine consumption of legumes and DCM, they don’t know how the former causes the latter.

The researchers specifically looked at compounds in grain-free dog food that have been flagged as the FDA as potentially causing DCM. 

But they believe more research is needed into how pulses may cause the condition and aren’t advising a product recall for grain-free dog foods just yet. 

‘Until we know the exact cause, we want to be cautious of all the ingredients the FDA is investigating,’ study author Dr Lisa Freeman and Tufts University told NBC News.

‘Peas might be a good clue as to where we can be looking. 

‘As one more piece of the puzzle, this doesn’t give us the final answer, unfortunately. But it gives us things to follow up on.

‘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 and prevent other dogs from being affected.’ 

The study suggests the dangers of giving your dog peas and other pulses – whether or not they’re an ingredient in dog food or fresh from your dinner plate – although many veterinary organisations say it’s fine to do so.

For example, American Kennel Club (AKC) says dogs are fine to eat peas ‘on occasion’, as long as they’re not tinned as these tend to have added salt.  

AKC has a list of vegetables on its website that it says are either OK or not OK to give to your dog.  

The UK charity People’s Dispensary for Sick Animals (PDSA) also says peas are safe to give to your dogs as long as they’re not tinned. 

MailOnline contacted the Kennel Club, the British Veterinary Association, the British Small Animal Veterinary Association, the Royal College of Veterinary Surgeons and Pet Food Manufacturers’ Association for comment. 

British Veterinary Association senior vice president Daniella Dos Santos said: ‘We’re following this investigation into the link between cases of DCM and certain pet foods with interest. 

‘As the FDA has stated, this is a complex scientific issue that may involve multiple factors, though the overarching link appears to be grain-free diets.’

Dos Santos recommends caution for dog owners in choosing a grain-free diet for their pet

‘We always welcome pet owners taking an interest in the sourcing and ingredients of their pet’s food, but there is currently insufficient evidence to substantiate any of the beneficial health claims of a grain-free diet,’ he said. 

‘We’d encourage pet owners to talk to their vet for advice on a healthy, nutritionally-balanced diet that is tailored to the animal’s life stage, breed, specific health needs and lifestyle.’ 

For their study, the researchers compared 830 compounds in nine traditional dog foods to nine that have been associated with DCM by the FDA. 

The DCM-linked dog food products were dubbed 3P/FDA in reference to the three pulses that they contain – pulses, potatoes and sweet potatoes – as a replacement for grains like rice and corn, to supplement the meat. 

In all, 122 compounds were significantly higher in the 3P/FDA foods than in traditional foods, of which 24 were amino acid-related and 20 were plant compounds. 

A machine learning algorithm called random forest analyses narrowed the number of suspect compounds to 30. 

Peas were the most strongly associated with these 30 compounds, and it’s likely that the more peas that are in dog food recipes, the more likely a dog goes on to develop DMC, the FDA suggests.

Some of the suspect ingredients are in dog foods that haven’t been linked to DMC, the agency says, so it could be an issue of quantity. 

Genetic factors may also play a risk. It’s already known that DMC is prevalent in breeds such as Doberman Pinscher, the Great Dane, the Golden Retriever, the Boxer and the Cocker Spaniel.

‘Maybe if you have subpar nutrients and a particular genetic type, you might get the perfect storm,’ Dr Joseph Wakshlag, a professor of nutrition at the Cornell University College of Veterinary Medicine who wasn’t involved in the study, told NBC.       

According to the FDA, from January 1, 2014 to April 30, 2018 there were 524 reports of DCM – 515 for dogs and 9 for cats – submitted to the FDA.  

Between 2014 and 2021, more than 1,100 cases of diagnosed DCM have been reported to the FDA, at least 280 of which have died from the condition.  

The study has been published in Scientific Reports.