Sheffield Council joins a third of English and Welsh authorities which did not hand out a single fixed-penalty notice for fouling in 2014-2015, figures obtained by the BBC show.
Almost one in six had not fined anyone for five years, with the number of fines falling by almost 20 per cent in a year, from 3,521 in 2013-2014, to 2,868 last year.
Sheffield Council, which handed out zero fines last year despite 1,407 complaints, said it did not have the resources to patrol parks around the clock.
Coun Terry Fox, cabinet member for environment and transport, said: “Catching people in the act is difficult, and in these times of austerity we simply don’t have the resources to station people in parks or other places for hours on end, waiting for an offence to be committed.”
It is trialling other methods, such as a poster campaign, which saw a 76 per cent decrease in fouling in the areas piloted.
The figures were released as The Yorkshire Post’s Clean Up Yorkshire campaign, which is encouraging readers to host community cleans ups, gathers pace.
In contrast to Sheffield, Barnsley Council issued the most fixed penalties in England and Wales last year - 187.
Coun Jenny Platts said its approach to tackling fouling was “proactive and robust”.
Leeds Council received almost 1,000 complaints of dog fouling - up more than eight times from 2010/11 - but issued only around 30 fixed penalty notices.
Coun Mark Dobson, executive member for environmental protection and community safety, said it was “fed up” with dog owners who don’t pick up after their pets, but could only issue fines when an offence is witnessed.