Dublin City Council is paying €4,000 a month to clean up the debris left by the Smithfield horse market.
New figures released by the council show that the cost of mechanical sweepers and personnel is affecting cleanliness in the rest of the city.
"The cost of this clean-up restricts the council's ability to keep the city centre up to the clean standards we aspire to, especially as the start and finish times of the fair are unpredictable," said a spokesman.
Bernie Wright of the Alliance For Animal Rights (Afar) said the market has now descended into "chaos" and is being "run by cowboys".
"Last Sunday saw scenes of madness. There were fights breaking out, and the ISPCA had to walk around wearing stab vests. We have recordings and we will be sending them to government representatives to get rid of this market which is now just a sham," said Wright.
"The horses have been found set on fire, starved, mutilated and abandoned on waste ground with some being driven into the canal and drowned just for the fun of it. Pit bulls, rabbits, terriers also appear for sale; no doubt some of these animals on sale are used for fighting."
The council is now attempting to end the market after appealing to the government to ban horse markets in the city centre.
"To extinguish the market right at Smithfield, we would have to find an alternative location for the market... This would involve acquiring land, designing a facility, obtaining planning permission and building a facility, all of which in the current financial climate is not achievable," said the spokesman.