Labrador Retrievers were responsible for the highest number of personal injury claims after biting people, a new survey revealed.
Data from a leading a pet insurer has also shown that 35 per cent of all compensation claims for those injuries came from postal and delivery workers.
German Shepherds were the cause of the majority of the claims by posties and more than half (54 per cent) of claims were due to dogs not being kept secure properly.
Injuries recorded by insurers Animal Friends included the ends of fingers being bitten off and nerve damage as workers are attacked.
Their data showed how the majority of dogs were pushing past their owners to bite unsuspected delivery drivers and others were getting around open garden gates.
Following German Shepherds, the breed most likely to attack the delivery workers was Staffordshire Bull Terriers, Border Collies and then Labradords.
The figures come after the Royal Mail revealed there were more than 2,600 attacks across the country in the last year, with most attacks occurring in Nottinghamshire.
Earlier this year father Daniel Dythe, 40, was delivering a Christmas parcel when a Rottweiler-German shepherd cross chomped down on his penis – leaving him needing stitches.
In the last year 36 per cent of attacks on delivery staff happened at the front door while 35 per cent took place in the front garden.
The Royal Mail said the number of attacks is set to rise by 10 per cent during school holidays, as dogs are more likely to be in gardens unattended.
Claims made to Animal Friends included posties needing surgery, psychological treatment, nerve grafts and pins and plates placed.
The treatment of the injuries cost the NHS upwards of £20,000 and a potential claims value of £384,778 for just the cases involving Animal Friends customers.
Dr Roger Mugford, an animal psychologist, said the best thing for posties to do was befriend the dogs and keep them happy by always carrying a bag of treats.
He said: “Once a post man befriends a dog, they will be friends for life.
“To say that dogs can smell fear I am sure is very true. The way we move and the way we think is communicated to a dog.
“Dogs are really good at picking up on people and they remember everything, so the best advice is to make friends with them rather than enemies.
“More male postmen are attacked than women and that’s because men tend to become aggressive and defend themselves which can make things worse.
“But it is good to remember that it is remarkable that more dogs do not bite more people as they have a pack mentality and their family becomes their pack so they are protective.”
Westley Pearson, Director of Claims and Marketing for Animal Friends Pet Insurance, said: “As we can see from the above figures, dog attacks make up a large portion of insurance claims for pet owners.
“This is such sad news, as these incidents could be easily prevented.
“We would suggest that over the summer, owners keep a watchful eye over their pets when out in the garden, especially if your dog is large enough to see over a gate.
“If you’re unsure about your dog’s temperament with strangers, make sure to keep your pet on a long lead so they can still enjoy the outdoors without becoming a danger to others.”