Drivers of the horse-drawn coaches that tour Vienna’s historic city centre are fitting their steeds with “nappies” in protest at steep cleaning fees, a spokesman told AFP on Wednesday.

“The cleaning costs were too high and they could not afford to pay them. If he cannot pay the fees what can he do?” said Andreas Churda, head of the association of Vienna’s horse-drawn coaches, which are known as fiakers.

Two businesses have already fitted their horses with so-called poop bags — dubbed “horse nappies” by the Austrian media.

Last year Vienna City Council introduced annual fees of some 145,000 euros (143,000 dollars) for cleaning horse dung from the streets of the baroque city centre. Before then the council had paid the costs itself.

The fees are split between 142 fiakers but those who do not contribute to the mess do not have to pay the charges, Churda explained.

He said there were concerns the horse nappies were bad for the animals, restricting their movement and making some sore. “They should think about animal protection laws,” he said of the city council.

A spokeswoman for Vienna City Council’s environment department said it had commissioned vets to examine the poo bags to see if they hurt the horses.

“If the vets say the animals are not suffering then it could be a good idea,” she told AFP.

The fiakers touring Vienna’s city centre — and the traditional smell of horse dung that accompany them — are as much a part of the Austrian capital’s historic landscape as gondolas are in Venice.