They're bred to fight crime alongside the UK police force - but not all of them make it to the mean streets.
Police dogs embark on a strict training programme as puppies learning how to use their natural instincts on instruction.
Breeds commonly used by the UK police include German shepherds, cocker spaniels, labradors, springer spaniels, malinois and Dutch herders.
But not every dog who enters into the programme as a puppy will make it through The Dog Section, an exam which determines whether they have what it takes to work on the front line.
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Those who fail The Dog Section, whether it's because they're 'too friendly' or 'not brave enough', usually go on to be rehomed to families simply wanting to welcome a dog into their home.
Northumbria Police Dog Section has been inviting people to express their interest in rehoming one of their failed or retired police dogs, saying suitable owners will be contacted as soon as a dog becomes available.
A statement reads: "Northumbria Police Dog Section from time to time have dogs which are looking for a new home.
"Most of the dogs we rehome have not been police trained although we do occasionally have a retired police dog available. Most are under a year old and have failed to meet the required standards of The Dog Section.
"We match our dogs to potential owners. If you’re interested in owning a police dog, please fill out an application form and you’ll be added to our database.
"If we have a dog that could be a match to you, only then will we make contact. Northumbria Police only rehouse our dogs as pets and not for them to be used as guard dogs or for breeding purpose."
Although registering an interest in a police dog does not guarantee an adoption, people can specify what breed and gender they'd prefer and how much they'd be willing to pay for the dog, between £100 and £700,
Those interested will be asked where the dog will be kept, whether they have any other pets in their home, and how many hours per day would it be left alone.
The statement adds: "Unfortunately we will not be able to reply to every application. The rehoming database is not a waiting list; we like to match each dog to the most appropriate home.
"If we have a dog which we think you match with we will make contact with you by phone to arrange a suitable time for you to meet the dog and for a ‘home check’ at your address.
"During the rehoming process a Police Officer from The Dog Section will conduct a check of police records to assess your suitability as a potential owner.
"All dogs under the rehoming scheme are microchipped and it is a legal requirement of the new owner to have the microchip details updated to reflect the change in ownership."
If you're interested in rehoming a dog from Northumbria Police Dog Section, complete their application form.
Do you have a dog story to share? Email paige.freshwater@reachplc.com.
