Daventry District Council in Northamptonshire introduced the measures in December 2015.
It said owners should have to prove how they would clean up after their dogs to cut down on the problem of fouling.
The Dogs Trust said it questioned whether the policy was "effective" or "practical".
A council spokesman said while scores of dog owners had been stopped, nobody had been caught "unequipped".
It is understood the council has not received any complaints about the public space protection order powers.
Alex Jackson, head of campaigns at Dogs Trust, said: "We consider picking up your dog's poo to be an integral element of responsible dog ownership and fully support well-implemented orders on dog fouling.
"However, we question the effectiveness of issuing on-the-spot fines for not being in possession of a poo bag when out on a walk and, keeping in mind that no fines have been issued in this case, whether this is practical to enforce.
"We make poo bags freely available to all local authorities in the UK for distribution to their communities and do encourage owners to take poo bags with them when out for a walk.
"Any public bin can be used to dispose of dog poo so we urge local authorities to get this message out there and to provide more bins in public areas for this purpose."
Not a single fine has been issued by a council which made it an offence for dog owners to leave home without a poo bag, it has emerged.