At least 21 dogs a day are being put to sleep by local councils, according to a survey by a leading dog charity.
The Dogs Trust says healthy strays are being destroyed because their owners can't be found and no-one offers to take them on as a new pet.
The report also discovered that every five minutes another dog is either lost or abandoned by its owners.
The charity says the best way to reduce the number of strays is to neuter the dogs, so they can't have puppies.
The Dogs Trust also recommend getting a special microchip put in your pet containing their name and address, so you can be easily traced if your pet gets lost.
Although the total number of stray dogs destroyed is 22% fewer than last year, Dog's Trust Chief executive Clarissa Baldwin is worried so many dogs are still allowed to stray.
"It's also shocking that so many dogs are needlessly destroyed.
"Over 20 dogs die every single day just for want of a home," said Ms Baldwin.
One of the worst areas for stray dogs is Wales, where more than 11,000 pets were picked up last year.