Stray dogs cost Hackney Council more than £70,000 last year, a freedom of information request has revealed.

The authority has a legal responsibility to hold dogs found on the streets for seven days to give owners a chance to reclaim their pets – but only six of the 23 dogs put in the pound between October and November were collected.

Any canines not reunited with their owners are sent onto rescue centres after a week – but only if they are suitable for rehoming.

And an average of 40 of the 250 dogs a year which go through the pound’s doors are euthanised because they were either a banned breed, too sick or so aggressive that they could not be rehomed.

Feryal Demirci, cabinet member for neighbourhoods, said that “a lot of irresponsible breeding” was making the situation worse.

She described the issue in Hackney as “similar to many other inner city boroughs”.

“There are many reasons why dogs become strays. One reason is that taking on a pet is a real responsibility and some people don’t realise how much work it can be,” she said.

“Most of the dogs we take in are bull breeds, which some people keep as status dogs. These are dogs which in most cases are not micro-chipped nor neutered, so there is a lot of irresponsible breeding going on which makes things worse.”

Cllr Demirci also said the council was trying to promote “responsible dog ownership” with the help of charities.

She said: “People need to realise that when they get a dog they are making a 10-year commitment. Dogs need to be neutered to reduce the number of unwanted puppies and vaccinated to reduce the spread of diseases. It’s important that they are micro-chipped so that any animals that do end up in our hands can be quickly reunited with their owners.”

The council said illegal breeding was also a huge problem in Hackney, as it is nationally.

Michael Webb, public affairs manager at Battersea Dogs Home, one of the three charities which rehomes stray dogs in Hackney, said: “Dogs are cheaply or freely available on the internet or on the street. People can take a dog without understanding the responsibilities in looking after a dog for the rest of its life.”

“Given that that 53 per cent of all the Staffies arriving at Battersea in 2013 were under three years old, it seems likely that people buy them as puppies and then abandon them once the reality has set in.”