Three puppies have been found abandoned in a box down an alleyway.
The RSPCA said it was lucky they were found when they were as they are only about five weeks old and would not have survived for long.
The terriers, which have been named Peanut, Butter and Jelly, were found in an alley off Grainger Street in Darlington on Thursday night.
RSPCA inspector Claire Wilson said she was concerned for their mother and appealed for information.
She said they were "riddled with worms" and two are suspected to have hernias.
They were discovered by a man walking nearby who heard squeaking coming from the box.
The puppies are being fostered by vet nurses and will be rehomed once they are old enough.
Ms Wilson added: "These pups are too young to leave their mother and I dread to think what would have happened if they hadn't been found so quickly.