Since 1996 it's been illegal to own pit bulls, fila brasilieros and other "dangerous" dog breeds, but the RSPCA says it's time to change that.

The animal welfare charity argues that breed specific legislation (BSL) simply does not work and means well-behaved, socialised animals often suffer or are even destroyed, just because of the way they look.

This week marks 25 years since the introduction of the Dangerous Dogs Act, which banned ownership of breeds such as the pit bull terrier, Japanese tosa, fila braziliero or dogo argentino.

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But the RSPCA says the law has done nothing to safeguard the public and causes animals - and their owners - to suffer unnecessarily.

They include Alex, a mixed bull breed who lives in north Kent with her owner Sian Morton.

By law, the five-year-old is forced to wear a muzzle and be kept on a lead during walks as part of his exemption conditions.

He is sociable and easy-going, but cannot chase a ball or run as he has to be attached to his lead and the person walking him.

His owner has even bought chest waders so Alex can go swimming.

Sian says: "He is seriously conflicted when you say it's time for a walk. He loves walks but hates his muzzle so his tail wags but, as he slowly puts his face into the muzzle his back drops like a defeated dog.

"He wants to have fun but fun is always at a price for him.

"He can't just jump in the water and play like the other dogs do, so my husband bought chest waders and goes in with him. It is the only way he can do something he loves within the confines of his exemption restrictions.

"As he slowly puts his face into the muzzle his back drops like a defeated dog. He wants to have fun but fun is always at a price for him" - Sian Morton

"He wants to be friends with everyone and he looks at people with confusion when they drag their dogs away or cross the road to avoid him. He doesn't understand and, to be honest, neither do I.

"Alex spends a great deal of his life watching and waiting. Watching other dogs do things he wants to do, watching people walk away and waiting for change.

Sian is backing RSPCA's campaign calling for an inquiry into the law.

She adds: "It lulls the general public into thinking that the four banned breeds are the only ones capable of biting, the only 'dangerous' ones.

"We need stricter regulations on breeding and neutering, education programmes in schools, youth centres, housing estates etc. and we definitely need more positive stories in the media."

RSPCA dog welfare expert Dr Samantha Gaines says: "The police, the RSPCA and other animal rescue organisations have to deal with the consequences of this flawed law by euthanising hundreds of dogs because legislation is forcing us to due to the way they look, despite being suitable for rehoming.

"Not only is this a huge ethical and welfare issue, it also places significant emotional strain on staff.

"It is the view of the RSPCA, and the public, that every animal’s life matters.

"We conclude that breed specific legislation has not achieved its objectives whilst causing unintended harms - a new approach is required.

"The RSPCA believes it is paramount for the government to launch an inquiry into the effectiveness of BSL, assess other options to improve human safety and dog welfare, and ultimately repeal the breed specific part of the legislation."

Figures from the NHS Information Centre suggest the law has at best been ineffective.

Since 1989 the number of hospital admissions for dog bites has risen steadily, with no dip following the introduction of the Dangerous Dogs Act in 1996.

The RSPCA is also concerned that labeling some breeds as dangerous gives the misleading impression that all others are always safe.

Dr Gaines said: “Until such time that BSL is repealed, there needs to be urgent action to protect the welfare of dogs affected by this law.

"In the absence of any evidence to show that BSL is effective in safeguarding public safety, it is the very least that we can do for man’s best friend."