Durham Police said six American bulldogs, which were being walked in the Belmont area of the city, fought with a Staffordshire bull terrier before attacking a man and two women.
A 48-year-old man, understood by the BBC to be dog breeder Stephen Potts, is being questioned by the force.
Mr Potts was attacked near his home in High Pittington last month.
Police said officers were called earlier to Coniston Close.
A spokeswoman said the dogs were being walked by a man and a woman.
The woman suffered bites to her hand and a 63-year-old man who was walking the Staffordshire bull terrier was taken to hospital with serious head and calf injuries.
A woman walking nearby was also attacked by one of the dogs and is being treated for injuries to her leg, police said.
Neighbourhood chief inspector for Durham Andy Huddleston told BBC Tees that 14 dogs had been seized, including a number which were taken from Mr Potts' home.
A man who had his arm amputated after being mauled by his own dogs has been arrested over a series of dog attacks.