Pet owners are being warned that close affection with their dogs and cats may be life-threatening.
Treating them like a human by giving kisses or cuddles could spread drug-resistant bugs through saliva, scientists fear.
Psychologists quizzed scores of pet owners and discovered many are unnecessarily asking vets to give out antibiotics.
Bacteria can become drug resistant when people, or animals, take incorrect doses of antibiotics or if they are given out too easily.
This means bugs that strike pets could eventually develop resistance, and be passed onto humans who are too affectionate.
But the psychologists behind the study warn the behaviours are ‘so deeply treasured they are unlikely to be amenable to change’.
The researchers have now offered tips to help reduce the risk, with advice such as not kissing pets on the mouth.