'Ruth Quick recently bought a bag of Applaws Duck and Venison dry dog food with an expiry date of May 2019 — it was mouldy.

"I know of at least one person's dog who basically ate about half the packet of Applaws and became ill for about a good week with diarrhoea and just being very unwell," Ms Quick told 7.30.

The Federal Government is facing growing calls to regulate Australia's pet food industry, amid reports of poor quality pet food and claims manufacturers have too much influence.

A suspected link between the popular dry dog food Advance Dermocare and more than 70 dogs contracting the devastating condition megaesophagus has put the industry under scrutiny.

And a number of owners have now contacted 7.30 complaining of other pet food problems.

Do you know more about this story? Email 7.30@abc.net.au

'Anybody can produce whatever they want to'

A bag of Applaws with mouldy dog food ( Supplied: Ruth Quick )

Pet food is a growth industry. More than 60 per cent of Australian households own a pet and spend more than $4 billion a year feeding them.

There are no laws governing pet food safety only a voluntary standard.

Ms Quick said she alerted MPM Products, the manufacturer of Applaws, which conceded a manufacturing problem at its Australian plant.

She was stunned to learn the company was under no obligation to issue a public recall.

"That was one of the things I said to him (the Applaws manager), 'what about the people who had already purchased the bags?'," Ms Quick said.

She said it was frustrating owners had nowhere else to turn to complain about pet food other than the manufacturer.

"I've realised there's no one checking," she said.

"Anybody can produce and put out whatever they want to."

Veterinarian Dr Richard Malik said pet food recalls in Australia were rare because of the industry enjoyed a regime of self-regulation.

"Why don't pet food companies recall food quickly? That's easy. First they're in denial, second they don't want to lose money," he said.

"It's hard to take a food off the shelf because your brand really suffers.

"You don't make money and people question whether all of your other brands are okay or not, so there's great hesitancy to do anything like that."

He said Federal Government intervention was overdue.

"There have been so many examples over the last 10 years of toxicity from food that the government must act to do something," he said.

"To not act is to put their head in the sand."

A bag of Applaws dog food ( ABC News: Angelique Donnellan )

Pet Food Industry Association of Australia's Executive Manager, Duncan Hall, said there were few safety issues with the industry and it had operated well for more than 10 years.

"It is a largely self-regulated industry and over the last ten years that has served us well," he said.

"We are an industry that produces somewhere in the range of 30 million meals per week to pets, and Australian pets have been well served as far as nutrition and health throughout that time."

But he was open to a re-think on how the industry operated.

"Look I think all things must change and I think we are always open to working with governments and other key stakeholders, the AVA, the RSCPA," he said.

"We are always open to what could be done better."

Plastic discovered in dry dog food

Scraps of plastic in dog food ( Source: Facebook )

MPM Products said it had received about 20 complaints about mould and two reports of dogs becoming sick, but their illnesses had not been conclusively linked to the food.

The company also revealed coloured plastic found in its dry dog food two years ago came from a supplier failing to remove plastic ID tags from chicken carcasses before processing.

There was no public recall.

Some owners say Baxter's dog food caused their dogs to have seizures. ( ABC News: Angelique Donnellan )

7.30 also spoke to a number of pet owners who said Baxter's — made for and sold by Woolworths — had caused vomiting and diarrhoea in their pets.

There are also some claims of seizures and paralysis.

Unhappy owners have been told the product is safe, with some receiving supermarket gift cards after complaining.

A Woolworths spokesperson said the company took quality very seriously and undertook extensive and rigorous testing of products.

"In line with this approach, Baxter's has been quality tested multiple times to ensure the range complies with strict Australian standards. The manufacturer also holds an independent quality certification for the production of pet food to global food safety standards," they said in a statement to 7.30.

'If I'd just fed my dogs a different food...'

Vincent was euthanased after developing megaesophagus ( Supplied: Christine Fry )

Christine Fry is still coming to terms with losing one of her dogs to megaesophagus and has another pet battling the condition.

Both Great Danes, Vincent and Mabel, were fed Advance Dermocare.

"I was horrified to think that if I'd just fed my dogs a different food Vincent would still be with us now, " Ms Fry said.

Megaesophagus is a rare condition that causes a dog's oesophagus to lose its elasticity, causing food to get stuck and then be regurgitated.

Global company, Mars Petcare is the manufacturer of Advance Dermocare.

It first learned of a potential problem with its product in December after nine Victoria Police dogs that ate the food were diagnosed with megaesophagus. One was euthanased.

Ms Fry said she couldn't understand why it took until late March for the product to be taken off shelves.

"I find it really hard to believe the company didn't come forward and recall this earlier because while Vincent was sick I was still feeding him Advance Dermocare and I was continuing to feed Mabel Advance Dermocare as well," she said.

"There should be some regulations and I think the government needs to get on board before we lose anymore dogs to something else."

The Federal Agriculture Minister David Littleproud declined 7.30's request for an interview but said he's seeking state and industry support for a review into pet food manufacturing.

'Pressure on vets to keep quiet'

Dr Richard Malik says the pet food industry needs greater regulation. ( ABC News )

Dr Malik said if there was to be official oversight the regulator needed to be independent as he believed big pet food companies had too much influence.

"There's a lot of pressure on vets to keep quiet or at least not to put up a red flag that there might be a particular problem with a food or treat," he said.

"A lot of vets sell pet food including food that caused the megaesophagus in dogs, a lot of universities get free pet food, the AVA (Australian Veterinary Association) gets sponsorship from pet food companies."

National President of the AVA, Dr Paula Parker, said it received about a third of its revenue from sponsors but insisted there was no conflict of interest.

"We're fortunate to have a good relationship with them (the pet food companies) but we're clear about what the boundaries of those relationships are," she said.

She was happy with Mars Petcare's response to the megaesophagus outbreak.

"In this case the pet food company has voluntarily withdrawn and they're actively participating in resolving the issue which is fantastic and we commend them on it," Dr Parker said.

University researchers believe there is a link between Advance Dermocare and the spike in megaesophagus cases but are yet to scientifically prove it.

Mars Petcare has offered to reimburse owners' vet bills and pay the cost of a new dog to replace those euthanased.

The company has declined repeated requests for an interview.