Scientists are investigating possible links between the hospital superbug MRSA in pets and humans.
Between 10 and 20 pets are found to carry the bug each year
Experts said it was possible people were infecting pets, and vice-versa, after reports of cases in recent years.
The Department of Environment, Food and Rural Affairs has set up a committee to look at MRSA in pets and livestock.
Dogs, cats, a rabbit and a horse have all known to have had MRSA in the UK, while livestock in the US, Ireland and Canada have developed the superbug.
The first reports of MRSA (methicillin-resistant staphylococcus aureas) in animals came to light in 1972, but since 1999 there have been more frequent reports of animals having the superbug.
So far, all animals in the UK which have had it have had the strain of MRSA which is seen in hospitals, rather than the strain seen in the community.
The British Veterinary Association estimates between 10 and 20 pets are found to carry the bug each year, but has warned the number was increasing.
It advises vets to take similar precautions as are carried out in hospitals, such as using sterile gloves, scrub suits and masks during operations.
A government committee of health experts was set up in January to look into the issue.
But Defra said: "The overall significance of the detection of MRSA in animals in relation to public health is not known."
MRSA has been linked to up to 1,000 human deaths a year, but there has been a recent downward trend in the number of infections seen.
Dr Donald Morrison, of the Scottish MRSA Reference Laboratory, said his centre had received reports of pets developing MRSA and was helping the government research the issue.
"So far it seems to be a case of the patient passing it on to the pet, but there is no reason why it cannot be passed from pet to pet, and pet to human.
"However, it is too early to draw any firm conclusions, we need to look into this further.
"What is interesting that all the cases seem to be the hospital strain, which is very good at surviving and spreading.
"As for livestock, again it is possible."
However, he said it was very unlikely MRSA would be passed on to humans from drinking cows' milk or eating meat.