Dogs who have risked their lives in the service of Britain’s Armed Forces are being put down because they are “failing to maintain standards” including good behaviour, it has emerged.

Figures released by the Ministry of Defence show that nearly 40 military working dogs were euthanised in the ten months between March and December last year.

Of these six were put down due to their dangerous temperament, but a further six were destroyed because they did not meet the standards required by the military.

These include what the Army vets describe as “welfare, behavioural or temperamental issues”, including in some cases because they pose a danger to public safety.

Another five dogs were put down due to age or welfare concerns, while the rest of the 38 were euthanised after suffering a “range of medical conditions”.

Tim Farron, the former leader of the Liberal Democrats, has criticised the practice as “cruel”, saying more must be done to re-home former service dogs.

Some of the dogs who were destroyed had been previously used in conflict zones to protect personnel or sniff out explosives, potentially saving the lives of hundreds of British troops. It is thought a number will have served tours of duty in Iraq and Afghanistan.