A beloved family dog who was given three months to live after being diagnosed with a rare type of cancer is still living years later, after taking part in a Queensland clinical trial.

Key points: Rottweiler Griffin's tumours were growing at a rapid rate

Rottweiler Griffin's tumours were growing at a rapid rate Undergoes treatment that uses part of a tumour to create bespoke vaccine

Undergoes treatment that uses part of a tumour to create bespoke vaccine UQ researchers looking for more dogs to prove the vaccine works to send cancer into remission

Adam Johnson noticed a lump on his dog Griffin's back in December 2017.

"I thought we'd take him for a routine check," Mr Johnson said.

"It didn't seem like anything untoward, I just thought it would be medication and 'he'll be right' sort of thing.

"A few days later we found out it was a cancerous lump.

"It was devastating, absolutely devastating right before Christmas."

Griffin's owner Adam Johnson and daughter Layla. ( ABC News: Ashleigh Stevenson )

The rottweiler was diagnosed with T-cell lymphoma and given three months to live.

Veterinarian and University of Queensland PhD candidate Dr Annika Oksa said that type of cancer was usually a death sentence for dogs.

"He had a really big lump taken off his side but by the time he went back to have his stitches removed from the original surgery, he had another three lumps, so they were growing really quickly," Dr Oksa said.

Rather than the more traditional route of chemotherapy, Griffin was enrolled in a medical trial using immunotherapy treatment, designed to "wake up" the dog's own immune system so it recognised a foreign cancer.

"I took a sample from his tumour, at the time when I saw him he had 11 lumps on him," Dr Oksa said.

Dr Annika Oksa was giving Griffin weekly injections during the treatment. ( ABC News: Ashleigh Stevenson )

Once a dog was diagnosed with the cancer, the trial's researchers removed a small piece of the tumour and mixed it with a chemical to bolster the dog's immune response.

This was then injected back into the dog as a vaccine, each week for a number of weeks or months.

"With this one we make it specifically from the dog's own tumour," Dr Oksa said.

"So it's very, very personalised and then we hope that the dog's own immune system will recognise the cancer and start fighting it."

UQ researchers say they need more dogs to conduct the trials. ( ABC News: Ashleigh Stevenson )

Mr Johnson said as the weeks of treatment progressed, he was surprised by the results.

"One by one, the cancerous legions began to disappear to the point where two years on we've still got him here," Mr Johnson said.

"At that point in time it felt like a Hail Mary.

"My little girl has still got her dog."

Dr Oksa said researchers were encouraged by the results.

"Eventually at about week eight or so, when it came time to have a look at him again there were no lumps. That was fantastic," she said.

"Griffin is really rare because he had such a bad disease.

"We've had a number of dogs respond to this treatment and do really well but they were ones we'd hope would respond. With Griffin it was a surprise.

"We're hoping that this will be a way forward to include in the treatment protocol for these dogs.

"We need to have more dogs in the trials obviously, so we have more evidence.

"So at the same time we're researching what happens to the tumours, how do they respond to the vaccine — can we make any changes to it? Or combine it with different treatments."

Scientists hope to expand the research into human trials for similar cancers in years to come.