The dogs then turned on her, leaving her with a number of bites and a significant tear to the back of her thigh, she said.
Both women were taken to Palmerston North Hospital by ambulance.
"I understand they'll be in hospital for some time," the spokeswoman said.
Both dogs were seized at the scene and police are now taking photographs and doing forensics.
The council's animal control officers are looking at prosecuting the dogs' owner.
"This was a very nasty attack that shocked experienced animal control officers, " said council community services group manager Tamsin Evans.
"It must have been a terrifying ordeal for the women involved and has left them with serious wounds that will take time to heal."
Anyone with any information should call Otaki Police on (06) 364 7366.