Dogs can be trained to detect more than 90 per cent of Covid-19 infections even when patients are asymptomatic, according to research, which authors hope could help replace the need to quarantine new arrivals.

Using their remarkable sense of smell — which can pick up the equivalent of half a teaspoon of sugar in an olympic-sized swimming pool — dogs have already shown that they can sniff out maladies such as cancer, malaria and epilepsy.

Authors of the research, which has yet to be peer-reviewed, said they hoped it could eventually replace the need for travellers to quarantine — which necessarily disrupts every arrival even though the vast majority are not Covid positive.

“The key thing is that dogs are significantly quicker than other tests,” said co-author James Logan.