The 'stealth mules' of world war

By Steven McKenzie
Highlands and Islands reporter, BBC Scotland news website

Mules were used to carry supplies and weapons

Before hi-tech fighter jets with the capability to avoid detection, there was the "stealth mule".

With their voice boxes removed to keep them silent, the animals were used to carry supplies behind enemy lines in Burma in World War II.

Ian Robertson, a veterinarian who was brought up in Moray, was among those tasked with de-voicing mules.

The pack animals were crucial to General Orde Wingate and his British Chindit raiders.

Thousands of mules and horses underwent the operation under local anaesthetic.

It was deemed necessary as their braying could be heard for miles in the jungle and would alert Japanese forces to the presence of the raiders.

The operation is quite simple and not too traumatic for the animal, but its welfare afterwards can be a concern Andrew Trawford The Donkey Sanctuary

Called the Hobday's operation, after veterinary surgeon Sir Frederick Hobday who developed the technique, it is still done today using modern pain relief to remove paralysed vocal chords of race horses to allow them to breathe better.

The process of de-voicing was a dreaded task among ordinary soldiers who tied up and then held down the animals.

In a posting on the Burma Star Association website, one veteran described the overpowering smell of chloroform and the sight of blood.

He said the cut-out voice box was like a tiny piece of jelly. Soldiers would watch as the dazed animals tried to call out, but make no noise.

Gen Wingate's Chindits - a play on the name chinthe, which are mythical Burmese lions - operated deep behind the Japanese lines.

Their aim was to cause chaos and to help reverse Japan's success at jungle warfare.

Mr Robertson was attached to this special force and his duties included carrying out de-voicing.

STEALTH FACT FILE Stealth - the capability of not being detected - has been prized by the military for centuries. Modern weapons with the capability include the US Air Force's F117 and B2 Stealth Bomber, which were invented in the 1980s The technology is being developed for warships The futuristic DD21 destroyer has been among stealth warships the US Navy was working on

Born in London in 1916, he was brought up in Elgin where his father was a GP and surgeon.

He attended Springfield House School, Elgin Academy and later Robert Gordon's College in Aberdeen.

Interested in animals from a young age, he studied at the Royal (Dick) School of Veterinary Studies in Edinburgh rather than follow his father into medicine.

Mr Robertson volunteered for the Royal Army Veterinary Corps in 1941 and service took him all over the world and saw him rise to the rank of major.

His postings to military dairy farms and his work with mules give a brief glimpse into less well-known wartime activities.

Married with three children, he continued to take work abroad after leaving the Army in 1947.

Mr Robertson later returned to Elgin where he died four years ago.

An exhibition relating some of his wartime exploits is on display at Elgin Museum.

Andrew Trawford, director of veterinary services with UK charity The Donkey Sanctuary, said the wartime practice of de-voicing mules was taught as a history lesson at vet school.

He said: "The operation is quite simple and not too traumatic for the animal, but its welfare afterwards can be a concern.

"The animal is not able to communicate and mules are noisy, especially when trying to attract a mate and it is said their call can be heard to up to two miles away.

"It is not an operation I have ever had to perform."