Understandably, it is not a situation any animal fan would like to find themselves in. So why do so many fail to get their pets microchipped?
"If you ever become separated, it could make the difference between your pet being lost permanently and a happy reunion," explains PDSA senior veterinary surgeon Sean Wensley. "Getting your pet microchipped is an important part of responsible pet ownership."
The procedure is surprisingly simple and can cost as little as 15 to have done.
Vets use a needle to inject the radio chip the size of a grain of rice under the pet's skin.
Containing a unique identification number, the chip can be scanned if an animal is found, allowing details about the pet and its owner to be brought up on a central database.
Last year thousands of pets went missing in the UK, either escaping from their owner's home, getting lost while out on walks or even being stolen.
Unfortunately, many missing animals are never reunited with their owners.
This month, the PDSA is hoping to increase the number of pets who are microchipped, to allow them a better of chance of getting home if they go missing.
As part of National Microchipping Month, some PSDA clients can get their pets microchipped for just 10 throughout June.
To be eligible, pet owners must be in receipt of council tax or housing benefit and live within the designated postcode catchment area of their local PDSA PetAid hospital.
For more information, owners should visit www.pdsa.org.uk or call freephone 0800-731 2502.
Senior veterinary surgeon Andrew Hogg explains: "Microchipping is a really good idea. Obviously it is not necessary for every animal, including cats who stay indoors.
"But for those who roam about, they can easily go missing.
"Dogs can often just disappear too and every year, many get picked up by wardens. Sadly, some are just left in shelters – microchipping gives them a chance of being found.
"The majority of animals do not seem to mind the procedure taking place, and the chip cannot really be felt once it is in place."
Pet owners interested in finding out more can download a free copy of the PDSA's microchipping leaflet at www.pdsa.org.uk/pethealth leaflets.