More than three guide dogs on average are attacked by other dogs every month in the UK, a report says.
A review of 100 such incidents published in Veterinary Record found that nearly two thirds of the attacking dogs were off their lead at the time.
Either owners or members of the public were injured in a fifth of the attacks.
The authors warn that guide dogs can be so traumatised by an attack that they are unable to work. There are about 4,500 working guide dogs in the UK.
Further studies are planned in the coming years to determine whether such attacks are a growing problem.
Excluding cross breeds, almost half of the aggressors (just under 46%) were bull breeds - bulldogs, mastiffs, bull terriers, pit bull types and Staffordshire bull terriers.
Information on canine attacks on guide dogs between November 2006 and April 2009 was analysed for the report.
Almost two thirds of the attacks - 61% - were made on dogs that were in harness and working with their owner or trainer at the time. 86.7% of the aggressor dogs and 62% of the victims were male.
Labradors, golden retrievers, and retriever cross breeds were the types of dog most likely to be attacked, with most of the incidents taking place in public places and in daylight hours between 0900 and 1500 hours.
Most of the attacking dogs - 61% - were off the lead at the time.
As a result of the attacks, 41 guide dogs needed veterinary care. In one in five cases, either the handler or a member of the public sustained injuries, including scratching, bruising, and bites to the hands, ankle or head. In eight of these 19 cases, medical attention was required.
The attack affected either the performance or the behaviour of about half the guide dogs attacked - 45%. Two dogs had to be withdrawn from guiding service.
Guide dogs are supported by the Guide Dogs for the Blind charity and it costs about £50,000 to maintain a guide dog during its lifetime.
Guide Dogs for the Blind said: "The financial implications of attacks on guide dogs should not be underestimated, especially if retraining or replacing a guide dog is necessary.
"Most importantly, a person in critical need of a guide dog may be without one for a period of time while waiting for a suitable replacement to be trained. This will impact on their quality of life and mobility."