Surgeons are warning dog owners not to wrap leads around their fingers or wrist because of the dangers of serious hand injury.
They say thousands of people could be at risk from lacerations, friction burns, fractures and ligament injuries.
There were 30 serious hand injuries caused by dog leads last year in Cornwall alone, the British Society for Surgery of the Hand said.
One of those was to Jillian Tisdale, 65, who has two retrievers.
WARNING: GRAPHIC IMAGE OF FINGER INJURY FOLLOWS BELOW
'Like a filleting knife'
She had just finished walking one of her dogs when it became distracted by another dog and ran off excitedly on the lead.
The lead ended up wrapped tightly around Jillian's middle fingers on her right hand, causing severe damage, including the "degloving" of her finger - when the skin and some of the soft tissue are ripped off.
She said the retractable lead she used acted like a "filleting knife", causing "terrible pain".
She also suffered severe cuts and dislocated her index finger, after the incident several months ago.
Jillian needed surgery to remove the top part of her middle finger and a skin graft. She has been left with a shorter middle finger, as a result.
"I still can't form a proper fist yet and I'm continuing to do exercises to strengthen my hand," she says.
But she said she was planning to return to her hobbies of diving, mountain climbing, and even dog-walking, soon.
Jillian was treated by consultant surgeon Rebecca Dunlop, from Royal Cornwall Hospital in Truro, who also collected the data on hand injuries from dog leads.
She said she had noticed an increase in this type of "devastating" injury in recent years, which can need long-term treatment and means the fingers often do not return to normal.
Mrs Dunlop said: "Having seen many serious injuries caused by dog leads and collars, I want dog lovers to be aware of the simple steps they can take to avoid severe damage to their hand."
She said hand injuries could also be very costly "through time off work and medical costs".
To avoid injury, dog owners should:avoid hooking fingers under a dog's collar not wind the lead - particularly retractable ones - around their hand or fingers only use retractable leads in open spaces because they can wrap dangerously around legs, trees and furniture keep larger dogs on a shorter lead to avoid them building up speed that can cause a wrenching force