Hero hounds who show why police dogs are crucial despite animal rights activists' concerns, from saving a cop from a knife attack to stopping a building from being blown up

Brave dogs protect the public and their owners by serving in the police, and often get shot and stabbed as a result.

Many save lives in other ways, cheering up their handlers after a traumatic case.

In 2019, seven hero hounds were given an 'animal OBE' for their work clearing the streets after Westminster Bridge and Borough Market terror attacks.

The Metropolitan Police also employed the courageous K9s in the summer riots which tore through the country after the tragic Southport stabbings at the end of July.

But animal activists say dogs should not be used in efforts to combat crime because they are ending up as collateral damage far too often.

Campaigners decided enough is enough following injuries to canines on the front line and say the use of animals must be 'phased out' and replaced with a more ethical alternative.

The Commissioner of the Metropolitan Police has been encouraged to 'phase out the use of dogs' amid rising risks to their welfare and improvements in technology that can see their roles replaced.

It is the first time the organisation has requested UK police forces reconsider the age-old practice of training and using dogs to assist them in their work, for which the furry officers are crucial.

German shepherd Finn won the hearts of the nation for his selfless actions and even had a law named after him.

He saved the life of PC Dave Wardell, from Hertfordshire, when a robbery suspect turned on them with a hunting knife in 2016.

The officer was injured on his hand and the dog suffered serious stab wounds to the chest and head - but Finn refused let go until back up arrived.

Vets thought Finn would die from his injuries but he fought through, recovered and returned to duty, before he retired in 2017.

Finn was honoured with the PDSA Gold Medal for his bravery.

At the time, only criminal damage charges could be brought over the injuries to Finn.

But he was involved in the campaign that led to the Animal Welfare (Service Animals) Act 2019 which changes this - nicknamed Finn's Law - and he was at Westminster when it was cleared in Parliament.

Police dog Ozzy was also awarded the PDSA Gold Medal for his bravery and life-saving actions disarming an armed assailant threatening to blow up a block of flats.

Before his retirement, nine-year-old PD Ozzy worked for Police Scotland. In 2015, Ozzy and his handler, Police Constable Brian Tennant, were called to an incident at a flat in Falkirk, where a man had assaulted two people at knifepoint.

On arrival, they discovered the man had severed a gas pipe and was threatening to blow up the building.

The occupants of the flats were evacuated, leaving PC Tennant and PD Ozzy able to enter the building. The armed assailant charged at them, shouting threats, while attempting to ignite the gas with a lighter.

After warning the assailant, PC Tennant released Ozzy, who bravely tackled the man to the ground, where he was disarmed and arrested.

PD Ozzy's intervention prevented the man from harming himself, potentially others and causing extensive damage to the building.

In 2016, PD Eva jumped through a police car's open window and barked as she raced towards a suspect.

Two human police officers were struggling to detain the man who was thought to be armed.

She jumped at his chest and threw the man off balance, which gave the officers the chance to detain him. A knife was later said to have been discovered at the scene.

PC Gareth Greaves, from Manchester, met German Shepherd Theo at 14-weeks and they have been inseparable ever since.

The animal has not only saved his life in a physical sense, protecting him and other officers from a petrol cannon in 2016, but also gave him a new lease of life when is mental health was declining.

Father-of-two Gareth told on This Morning that at his lowest he was struggling to deal with grief and the pressures of work, but was 'brought back to base line' by Theo and his two children.

He said: 'One of the major problems with men and police officers is we don't discuss our mental health, and we are human.

'I've been struggling along time, a lot was going on in my life a lot of pressures. I'd lost a lot of people and my life had changed, the pressures of work were very difficult.

'We struggle all the time and at my darkest moment, I always thought about my two children obviously, that would always bring me back to base line.

'But one of the fundamental factors was that night when I left home, if I didn't return home, who would let him out? Who would feed him?'

Theo and Gareth were chasing a man who has stabbed a woman and shown intent to harm his children at the end of a night shift in 2016.

At the scene there were two officers were remaining a distance away from the agitated man, who was armed with a petrol cannon and a knife.

After the man launched the cannon Theo launched himself in front of the officers, and while still on fire chased after the man who was still carrying his knife and latched onto his leg with his teeth.

'He tackled an individual armed with a petrol cannon and a knife', explained Gareth.

'He put himself in the way and he ended up being set on fire and even when he was on fire came back and defended us all. His loyalty knows no bounds'.

Theo is now retired, but that doesn't stop him wanting to go out into the Line of Duty and Gareth explained he has to 'sneak out of the house' in his uniform, so that his dog doesn't know he's going to work.

Retired 10-year-old labrador Bruno was among four British Transport Police (BTP) dogs who searched for explosive devices after the Westminster Bridge attack in 2017.

His handler PC Robert Smith said he was happy to see Bruno rewarded as the dogs are often 'unsung heroes' during police operations.

Asked about the way the dogs work, he said: 'It's all planned reward, the training, they associate the smell with finding a tennis ball.

'That's what he thinks in his mind he'll be getting at the end of each search. They wouldn't do it if they didn't want to. It's pretty much a game to them.'

The first formal police dogs began work in Britain in 1908 in Hull.

Alsatians - also known as German shepherds - became the go-to police dog following the First World War where Brits noticed their power, intelligence and trainability.

The dogs would assist German soldiers in detecting enemy movements in the trenches from distances that aren't possible for a humans. They also aided wounded soldiers and carried supplies.

There are now more than 2,500 dogs used by police in the UK, according to estimates, with the Met alone having about 400.

Dogs are used by a range of forces for a many different purposes including tracking suspects, riot control, bomb and drug detection, and search and rescue.

The Alsatian is still the most common general purpose police dog and some are also trained as specialist urban search and rescue dogs.

Spaniels and Labradors, known for their temperament and sensitive noses, are the main choice for detection dogs.