Sharing is caring, right? Well, your dog might be giving you more than you bargained for, as a new study has found that your four-legged friend could be a source of urinary tract infections (UTIs).

The study looked at people who were diagnosed with UTIs in Copenhagen, Denmark, and then tried to understand whether or not their pets could be a potential source of the infection. Publishing their findings on bioRxiv, the researchers found that in a few cases, the patients' dogs might actually have been harboring the strain of E. coli that caused the condition.

Urinary tract infections are caused by bacteria typically found in poop entering the urinary tract and making their merry way up to the bladder. It is far more common in women than in men – with around half of all women expected to get a UTI at some point in their lives – simply because the urethra is much shorter so it is easier for the bacteria to infect the bladder or kidneys.

When the bacteria enter the bladder, they start to multiply and cause the infection. This can result in many uncomfortable symptoms, including a burning sensation while peeing, urine that is cloudy and smelly, blood in the pee, or even just frequent urges to go to the toilet. Treatment is fairly straightforward, requiring a dose of antibiotics.

Researchers at the University of Copenhagen studied 119 people who had been treated for UTIs, finding that 19 of them lived with pets. They then asked these pet owners for a sample of their own poop, as well as a sample of their pooch's poop.

After sequencing the bacteria found in both samples, they were able to identify two dogs from separate households that both carried the same strain of E. coli bacteria that led to their owner’s infection. But this on its own didn’t identify the pets as the cause, as the humans may well have passed the bacteria onto their dogs, rather than the other way round.

To figure out who infected whom, the researchers got the participants to wait 10 months and then asked them to send in another batch of poop samples for them to sift through. The results from this showed that while one of the dogs was clear of the bacteria, one was still harboring the same strain that caused its owner’s infection. This, the researchers argue, indicates that the canine might be persistently carrying the infection, which it then passed to its owner, although they cannot prove this definitively.

How the dogs may have been passing it on, or whether other pets could also be a source, is still not really known, although the researchers do suggest that cats could also be culprits. Basically, they recommend a few precautions, such as washing your hands and not letting your pooch slobber all over your face. Charming.