United States researchers have used a dog to sniff out thyroid cancer in people who had not yet been diagnosed, CNN reports.

The tests were carried out on 34 patients and showed an 88% success rate in finding tumours.

The team presented their findings at the annual meeting of the Endocrine Society and said the animal had an "unbelievable" sense of smell.

Cancer Research UK however said using dogs would be impractical, but discovering the chemicals the dogs can smell could lead to new tests.

Previously, a team at the University of Arkansas for Medical Sciences (UAMS) had previously showed that a dog could be trained to smell the difference between urine samples of patients with and without thyroid cancer.

34 patients who were going to hospital for conventional testing, took part in the trial and Frankie the test dog gave the correct diagnosis in 30 out of 34 cases.

Speaking on the development, Dr Donald Bodenner, the chief of endocrine oncology at UAMS said:

"The capability of dogs to smell minute amounts is unbelievable. The medical community over the next few years is going to have a great appreciation [for them]"

Several other researchers have described this as fascinating saying that the technique had a high potential to be developed .

The thyroid is a gland in the neck that produces hormones to regulate metabolism, thyroid tumours are relatively rare and are normally diagnosed by testing hormone levels in the blood and by using a needle to extract cells for testing.

For now, the lab is trying to find a new home for canine-veterans from Iraq and Afghanistan where they'll be trained to hunt for cancer rather than sniffing out bombs.