The circular theatre was dark. Swamp creature noises played over the sound system. Slowly we became aware that there were real animals in the blackness, and as the chirps and gurgles changed to birdsong and a spotlight warmed up, we saw a little herd of black Criollo horses standing in a sunken arena below us. The horses began to move. They dropped and rolled in the dark sand, showing white bellies. They fidgeted and flicked forelocks away from their eyes. They walked among one another, occasionally flattening their ears if a neighbour got too close. They shat at leisure, and the scent pricked our nostrils. Mostly, though, they pawed and circled, keen to roll and itch their backs. Ex Anima is the latest production of the French “Equestrian Theatre” Zingaro, founded and directed by the horseman Bartabas and now in its thirty-fourth year. I went to Zingaro’s wooden big top in the Parisian banlieue of Aubervilliers as a fan, desperate not to miss what Bartabas had said might be his last production. By the end of the performance, I hoped that Bartabas was right. I walked out without applauding.

Bartabas (the stage name of Clément Marty) is a prominent figure on the French cultural scene. He’s credited with inventing his own genre of theatre and is a Chevalier des Arts et des Lettres with a technical prize from Cannes for his 1993 film, Mazeppa. Past collaborators include Pierre Boulez, Pina Bausch, Dries Van Noten, and Philip Glass. In February 2018 he was awarded the Prix Marcel Nahmias by a jury of theatre professionals. Zingaro’s shows are usually exuberant or haunting combinations of dressage and the classic circus arts of vaulting, Cossack tricks and horseback acrobatics. Their originality lies in Bartabas’ stagings, a flow of non-narrative scenes with borrowings from sources as diverse as Kurosawa, Fellini, Mexican Calavera art and Roma culture.

When Ex Anima was unveiled with a teaser video in 2017, Bartabas explained that he intended to show horses purely as themselves, and that this should be spectacle enough: “this show would know how to bring the audience as close to the horses as possible, to what they really are when they are not in performance, for them to discover other beauty, so that they’ll [the horses] teach them [the audience] to surrender to wildness.” So Ex Anima had been stripped of almost all human performance, save the small band of woodwind players playing the original music. The horses appeared unridden or guided only by long reins so fine that they were invisible. They were directed by the human company, who, like Japanese Bunraku puppeteers, wore long dark robes and stocking caps knotted at the top, and disappeared into the shadows whenever possible. They didn’t even use voice commands, just bird calls jammed in their mouths: gulls, crows, garden birds. Sometimes they cracked whips off stage as if keeping wild animals at bay.

But while I remember moments of beauty – the first pastoral calm of the black horses at “dawn”; an Irish cob standing stock-still as six doves landed on his back; a grey draught horse hauling a beam across the ring, its quarters puckered with effort – these images were interspersed with disturbing scenes.

Two white Arab stallions, Majestic and Noureev, were released, floating down the steep ramp from the wings and racing wildly around the ring. Then they began to fight. Play fighting is common in horses, especially young ones, and it mimics real combat: horses try to nip each other behind the elbow, they kick, rear, embrace and nibble. The Arab stallions were mature and had an edge which did not suggest play. One locked onto the neck of the other like a hag fish, twisted, and, to the gasps of the audience, ripped off a chunk of coat or skin, leaving a visible pink patch that rapidly reddened.

Horses have their own politics. Send unfamiliar horses out to graze together and they will squeal, chase and kick before they settle. That’s why these encounters are usually supervised and take place where there is enough space for a horse to flee to safety, as a wild horse would. Bartabas claimed he was showing us horses as they truly were, au naturel, but all I could think of was the tale of the praying mantises who turned out not to eat their mates if they weren’t hungry and confined in a laboratory. Without human intervention, horses spend the majority of their time grazing, not prancing, which of course does not make for good theatre. The ring seemed to me not some primeval Eden of wild horses, but a sunken, black petri dish where horses were thrown together with the sole purpose of entertaining us.

A mousey gelding called Le Grincheux whom I recognised from Bartabas’s Equestrian Academy at Versailles was turned into the ring with a group of five of the black Criollos, known as La Troupije. An outsider, he ran harum-scarum around the perimeter of the ring to evade them. A gang of six young Welsh ponies, some only a year old, capered and reared nervily when hustled onto the stage; one stumbled badly as he galloped up the exit ramp. Bartabas called the show risky in his programme notes, but meant it in a theatrical sense: “Our horses ‘understand’ what they have to do. But we must accept that they’ll do it their own way, and evidently, we cannot control this in a precise manner.” I was more worried that both horses and humans were at physical risk.

A big, one-eared Lusitano called Van Gogh had the job of chasing a team of human handlers who ran at him, taunting him as they cawed through their bird calls like crows. He chased one up the bank at the edge of the ring and laid into them with his teeth – the actor had to beat the young horse off. The handler right in front of me was then pursued by Van Gogh, but dropped a treat that was the horse’s reward and frantically dug for another before the teeth could sink into him.

Perhaps Bartabas hadn’t really considered that the horses might not simply reproduce “what they have to do” but instead learn and change. I saw the show two months after it opened and it was due to run five nights a week until early March 2018. Perhaps when the first reviewers raved about Ex Anima, Noureev and Majestic could still play – but how could an experienced horseman like Bartabas not have realised that repeatedly throwing two mature stallions into a cockpit together would eventually result in bloodshed? Or that an instant reward of food would teach a two-year-old like Van Gogh to bite and threaten his handlers? What did Le Grincheux feel each night as he tried to escape the cliquey black horses of La Troupije? At the end of their encounter the black horses approached him with gentle curiosity, but then the gate to the wings was opened and the puppeteers began to crack their whips to drive the horses out. The politics of the horses themselves were not respected if they could not be aesthetically striking.

Even when the training was more overt, Ex Anima was uncomfortable to watch. Calacas, a little black Paso Fino with that breed’s distinctive rapid scurry, drooled and nodded his head busily up and down as actors kneeled before him and handed him treats that led to more compulsive head nodding. It looked more like a stereotype than choreography. Five La Troupije horses in long elephant-like gas masks appeared in a misty landscape and half clambered onto drums. Two shook and rubbed their heads as if the masks troubled them. A stallion mounted a dummy mare and ejaculated with a comical squeal. Circuses and arena shows like Cavalia offer more engaging liberty work than this, even if their style is cheery-cheesy rather than dystopian sophistication, but the most upsetting set piece in Ex Anima was saved for the finale.

The Irish cob Angelo was led into the ring and a hoist lowered. He tossed his head and stepped back, but was surrounded by puppeteers who fitted a solid leather sling under his belly and attached it to the hoist. Up Angelo rose, spinning as he went, his feathered hoofs leaving the sand and then rising twenty feet up through the air as his body slumped. Bartabas likes to think Angelo looks down on his human audience with contempt, but the horse couldn’t see because of his carefully arranged forelock – a small mercy. Meanwhile, his belly was bunched up in the sling. After an excruciatingly long time, he was once more lowered to earth and a treat crammed between his lips.

In Pour La Vie d’Artiste, his 2012 manifesto, Bartabas wrote: “To train a horse is not to make him acquire automatisms, it’s above all to construct a common vocabulary with him, then a shared grammar, then, if he wants, end by making poems together.” When I visited his Equestrian Academy in Versailles in November 2014, I saw this: the steady, daily work of the horsewomen and -men with their mounts, reaching towards a seamless, effortless dressage. Almost all horse training involves the old tricks of operant conditioning (where a horse learns that a reward or a punishment results from it making an action) or classical (where, roughly speaking, an animal learns that an outside stimulus like Pavlov’s bell means a reward or punishment), but the old magic of Zingaro made you forget this. The cues were artfully concealed; the performance held a degree of mystery. Each horse was presented in a way that highlighted and enhanced its beauty. Ex Anima only highlighted the fact that horses do not perform of their own volition or for their own motivations. They were not “actors” emoting independently and artfully. They were prodded by the Bunraku, had whips cracked at them, bit and drooled for food instead of making poetry with humans with whom they shared a bond. The daily meditation of Versailles and Alain Cavalier’s 2015 documentary about Bartabas’ and his horse, Le Caravage, was absent.

You can’t recreate natural behaviour in horses by force or manipulation – Xenophon knew that in 350 BCE when he wrote that “what the horse does under compulsion … is done without understanding; and there is no beauty in it either, any more than if one should whip and spur a dancer.” Bartabas himself told the Telegraph in 2011, “there is no limit to what you can do together because a horse, by nature, will never stop giving. He will give as much as you want, for as long as you ask him to give it. A horse would die for you if you asked him to.” The best horsemen and -women understand that it is up to them to set the limits on what they ask of horses.

In 2016, Bartabas was sued by Tom Waits for using his music in the previous Zingaro show, On Achève Bien Les Anges; although Waits lost, the production was canceled. Ex Anima was hurried into being as a result, and it’s hard not to wonder if this explains its flimsiness and Bartabas’ promise to make it his last show at Aubervilliers. I’d suggest an encore: if Zingaro wants to make truly radical theatre they can march those few thousand Parisians a night out to a damp field to watch horses graze and doze together for hours, and learn what it really means to “surrender to wildness”.