With the Zika virus threat now being downplayed by authorities in Brazil ahead of next month’s Olympics, a new scare has emerged after two horses were euthanised at the Olympic equestrian centre, writes Jack Burns.

Glanders is a disease that produces an incurable equine respiratory condition in equines, and Brazil has already destroyed hundreds of horses across the country in an effort to stop the epidemic.

Concern has been raised that two of the horses were put down in western Rio’s Deodoro Military Complex, where the Olympic equestrian events will be held.

However, in a report in the Wall Street Journal, organisers are quoted as saying the Olympic facilities are now safe and that they have followed strict international protocols to create a disease-free zone.

“Competing horses arriving at Rio’s international airport will effectively enter a protective biosphere, screened extensively for diseases and parasites beforehand, whisked to the Olympic venue upon arrival and quarantined there for the duration,” the article says.

The Journal also quotes Guilherme Marques, the director of animal health at the Ministry of Agriculture as saying that measures undertaken “totally ensure all of the necessary sanitary precautions, allowing for the participation and return of the animals to their country of origin.”

Caused by the burkholderia mallei bacteria, glanders can cause ulcers and lesions in the horse’s lungs, skin and respiratory tract. While donkeys and mules tend to die quickly, horses can carry the disease for years before succumbing to it. A zoonotic disease, it can also affect humans.

Central to the controversy, says the Wall Street Journal, is the lack of a definitive method for testing for glanders. The various options often yield inconclusive results and need to be carried out in conjunction with each other.

Critics argue that Brazilian agents lack the necessary expertise to conduct the tests. In addition, due to mixed results yielded by tests, a definitive diagnosis often only comes through a necropsy carried out once the animal has been killed. The Brazilian government does not provide compensation for damages related to glanders, according to the Ministry of Agriculture.

“We will have to accept that horses with questionable results will have to be culled for the sake of freedom of disease,” said Elke Reinking, spokesperson for the Friedrich-Loeffler-Institut in Germany, one of the world’s flagship research laboratories for glanders.

Ireland will be sending seven horses to the Rio Olympics – five to compete in eventing (including a travelling reserve), one in dressage and one in show jumping.

Read more at the Wall Street Journal