Experts have warned that dogs could be carrying the mcr-1 gene, which has built up a resistance to life-saving drugs. It is now thought that the bug, which was first identified in China in 2015, can be transmitted from animals to humans. Currently, drug-resistant infections are responsible for 700,000 deaths per year worldwide, the UN has said.
It warned that this number could rise to 10 million by 2050 if nothing is done.
A study examining the presence of the gene in households with dogs and cats was conducted by scientists at the University of Lisbon.
They examined faecal samples of 126 healthy people living in households with 102 cats and dogs across 80 households.
The study was conducted over a period of two years, up until February 2020.
It is thought that dogs can harbour mcr-1 in their gut before being transported via microscopic faecal particles.
In two of the households where dogs had tissue infections, the gene was present in both dog and owner.
It found that eight of the dogs and four humans were hosting bacteria including mcr-1.
While three of these dogs appeared to be healthy, the others had tissue or urinary tract infections.
The researchers also found that people living in agricultural regions that use colistin, particularly in southern European countries, are less likely to contract the mcr-1 gene.
Lead researcher Dr Juliana Menezes explained: “Colistin is used when all other antibiotics have failed, it is a crucial treatment of last resort.
“If bacteria resistant to all drugs acquire this resistance gene, they would become untreatable, and that’s a scenario we must avoid at all costs.
“We know that the overuse of antibiotics drives resistance and it is vital that they are used responsibly, not just in medicine but also in veterinary medicine and in farming.”
This is not the first time that experts have warned against sharing close physical contact with your pets.
Earlier this year, Dr Khaled Kasem, chief orthodontist at Impress, said that letting your dogs lick you could be damaging to your health.
He warned that the affectionate gesture could spread salmonella, ringworm or hookworm to their owners.
It can also cause gum disease in humans, Dr Kasem warned.
He said: “Dogs aren’t known for their hygiene.
“They don’t (usually) brush their teeth or rinse with mouthwash, and they’ve probably never visited a dentist.
“Their daily routine consists of eating leftovers on the floor, licking their bum, and checking out dead animals left on the pavement.
“Such activities result in a build-up of bacteria in your dog’s mouth, and although the majority is probably harmless, they can pick up parasites and bacteria that can make humans ill.
“Ultimately, their mouth is filthy.
“Whether they’ve drunk contaminated water or sniffed animal waste, these bacteria will not boost your immune health as some have argued.”
Speaking to Wales Online, the expert added: “Not only can human infection with pet parasites cause a wealth of intestinal diseases, but it also transfers damaging bacteria to your teeth and gums, causing gum disease.”