Sunburn can be as dangerous to dolphins as to humans. A 4-feet long dolphin found in a river has been euthanized after it was suspected of suffering from severe sunburn.

The mammal, which was found by a Kayaker on Saturday morning, was found stuck in reeds in the Kennall River in Cornwall.

Rescuers from the British Divers Marine Life Rescue (BDMLR) treated the animal but later decided to take it down instead of returning it to sea because of a huge blister on its back the size of a rugby ball.

BDMLR director and Cornwall area coordinator David Jarvis said that the blister on the dolphin's back was suspected to have been caused by sunburn. Putting the dolphin back to sea could cause the blister to burst and leave it open to infection and this could result in the animal having a slow and painful death.

"If you had a blister that covered approx 25 percent of your back & it opened up to reveal all of the flesh below, it would not only be very painful, but open to massive infection," Jarvis said. "It was therefore not an option to put the dolphin back into the water as it would have had to endure a long painful death, somewhere out at sea."

It is believed that the dolphin belonged to a pod that beached at Mylor Harbor on Friday and that the animal could not be persuaded to return to the sea. Some of the common dolphins could not be persuaded to go back to the sea and travelled up the river.

Jarvis said that the current theory is that after the animal have separated from the rest of the pod, it may have become stranded to where it was exposed to the rays of the sun for an extended period of time.

 Since there are no rehabilitation facilities in the UK, Jarvis said that the only alternatives they had were to either release the dolphin back into the wild or euthanize it to relieve its suffering.

It was apparent though that the blister on the animal's dorsal surface would eventually rupture prompting vets to choose the second option to spare the animal from a long and painful death.

 Animals that do not have scales, feathers and fur are prone to sunburn with dolphins and whales being particularly vulnerable to the damaging rays of the sun.