Preparations to sedate as many as 300 horses stabled at Belgrade's racecourse to keep them calm during a Rolling Stones concert have enraged Serb animal lovers who are lobbying to have the gig moved to another venue.
The concert is expected to draw more than 100,000 people to the Hippodrome, Belgrade's largest fenced space. The horses will be only a few metres from the stage.
"Horses differ, the same as people. Some are more nervous, more skittish," said hostler Jovanka Prelic. "If they get too nervous or start to panic during the concert, they'll get sedatives."
The 12 equestrian clubs at the course were hoping concert organisers would allow a sufficient number of personnel to be at the stables during the concert to give the animals the pills, Ms Prelic added.
Serbia's biggest animal protection society, ORCA, says holding the concert would be extremely harmful to the horses and sedating them is not the answer.
"Research has shown that noise and vibrations are the strongest causes of stress to animals," Elvir Burazerovic, head of ORCA said. "Surely our big city has enough open spaces where even 150,000 people can fit in. We think the Hippodrome should be left to horses," he said.
Moving the horses elsewhere was not an option, he added. "Transport also causes a lot of stress and besides, there's no alternative location for the horses," he said.
The sedative would be diazepam. In Serbia it trades under the name Bensedin, a very popular drug during the 78 days of NATO air strikes in 1999, when much of Belgrade's adult population was on tranquillisers.
ORCA said that if it failed to convince the organisers to change the concert venue, it would contact the Rolling Stones directly and ask them to use their influence.