The National Parks and Wildlife Service (NPWS) said it had "taken action to refuse entry to jaunting car operators" to the Killarney national park in the south west unless they have "the required dung catcher device".
Operated by so-called "jarveys", some 66 traditional carts, known as jaunting cars, carry tourists along 15 kilometres of internal roads within the picture-postcard park.
"An unfortunate consequence of such a high volume of horses frequenting the park is that the roadways are consistently fouled with horse dung, and has for a long time been a concern from the point of view of environmental, health and safety, aesthetic and tourism grounds," the NPWS said.
It said the majority of the more than a million visitors to the park each year walked the roads and it had received numerous complaints about the horse dung.
Over the years there have been a number of unsuccessful attempts to get the jarveys to use "equine sanitary devices" in the Killarney area.
The jarveys resisted, claiming the dung catchers will unbalance the carriages and the horses.
However, the NPWS, which is part of the environment ministry, says they are "in widespread usage internationally, from Vienna to Vancouver".
"It is clear, therefore, that these devices do work and are safe to use," it said. "Although the dung catcher is attached to the car and not to the horse, jarveys have repeatedly signaled their complete opposition to the new devices but have never demonstrated where they perceive the problems to lie."
The service emphasized its "desire to avoid conflict" but said it had been compelled to ban the jaunting cars as "a very last resort".
http://www.killarneynationalpark.ie/