It was feared Eskimo's testicle may have developed into a tumour
A reindeer at Edinburgh Zoo has undergone pioneering keyhole surgery to remove one of his testicles.
Specialist instruments were used to extract the teste, which had been lodged in the abdomen of Eskimo the reindeer since his birth.
It is believed the abnormal testicle was affecting his testosterone flow and may have developed into a tumour.
Eskimo had been displaying submissive behaviour and was being bullied by the other male reindeer in the herd.
He had also started to show some unusual and delayed antler growth and development. Removing the testicle will stop any abnormal hormone production and should see Eskimo return to normal.
Although keyhole surgery is routine in humans, the standard procedure in animals is still open abdominal surgery.
Abdominal surgery on animals is behind human medical advances and has a number of negative factors, including more post-operative pain, slower recovery and a higher risk of complications and infections.
Romain Pizzi, a veterinary surgeon for the Royal Zoological Society of Scotland, based at Edinburgh Zoo, said: "The operation was been a great success and Eskimo has made a speedy recovery.
"Laparoscopic surgery is still very uncommon in veterinary medicine, even amongst common species such as dogs, cats and horses, so for keyhole surgery to be carried out on a reindeer shows a great advancement in veterinary surgery.
"This procedure was only really possible thanks to a cutting-edge designed retractor which we were able to use in this case.
"Ironically, although a reindeer is a reasonably large animal, due to their unique anatomy and massive four-chambered stomach that takes up most of the space in the abdomen, there is a very limited internal operating space.
"For this reason the operation was much more difficult than in a human, or in a dog, where there is more space to work, despite their smaller size."
Eskimo was said to be standing and eating lichen again within 10 minutes of recovery from the anaesthetic.