THE video-sharing website YouTube has become a forum for animal cruelty, with viewers flocking to watch clips such as one of a tethered goat being fed to a python by laughing onlookers.

Animal welfare groups have attacked YouTube for hosting the footage, which also includes live mice and chicks being fed to piranha fish, and pets being thrown from tall buildings.

In many of the videos, spectators are heard laughing as the animals are made to suffer before, often, being fed to a larger and more valuable pet. A search on the site for “python” and “chick” turns up more than 30 videos of snakes being fed live chicks.

A large proportion of the clips on the site, which was bought last year by Google for almost £900m, are of cats and dogs engaged in harmless activities, and many have been viewed several million times.

However, the RSPCA described the videos showing animals suffering as “sickening” and said the cruelty found on YouTube went far beyond simply feeding one animal to another.

“We’ve seen every kind of animal abuse on YouTube, from clips of dogs fighting to one of a kitten being thrown off a fifth floor balcony for fun. It’s definitely not a joke; really it’s a sad reflection on our society,” a spokesman said.

The anonymity that YouTube users enjoy impedes efforts to prosecute, according to the RSPCA spokesman, who said: “To prosecute successfully we need to know not just who is responsible but also where and when the incident took place, and that’s almost impossible.”

In one clip a goat is seen sniffing and scratching at the floor of its cage as a trapdoor opens and the head of a python emerges. The snake then begins to coil itself slowly around the goat.

As the python strengthens its grip and the goat fights for its life, a man’s voice is heard shouting: “Come here, bitch!” A girl laughs while another man, clearly excited by the demise of the goat, says: “It can’t breathe.” According to the video time counter, it’s all over in 2min 42sec.

The scene has been viewed more than 5,000 times and has been awarded three out of five stars by viewers, with more than 30 people listing it as a “favourite” clip.

In another sequence, set to a gentle musical soundtrack, a mouse is released from a small box. It runs around the carpet for a few moments until a hand lifts it up by the tail and drops it into a tank containing piranha fish. Within seconds the water has turned red with blood as the piranhas rip the mouse to shreds.

Comments posted by other YouTube users include: “Haha-hahahaha!!!! BRILLIANT,” and “Hard core”.

Many of the videos showing cruelty emanate from America, where the vast majority of YouTube subscribers live. However, some appear to be made in Britain. In one, put on the site by a London resident, a python is shown eating a dead mouse.

The maker, who uses the name youronlynightmare, states on his space on the site: “I do realise people can find them offensive, if they feel sorry for the mouse or rat . . . but it’s nature.”

In other footage a British family on safari films two lions attacking and killing a giraffe. When the lions begin to eat the giraffe, a child is heard crying in distress. As the parents film the attack and discuss it, they complain at one point that the dead giraffe is blocking the road.

Psychologists say that people who are cruel to animals tend to be cruel to other human beings. Suzanne Conboy-Hill, a psychologist, said: “Research in the United States shows that often people who have been imprisoned for violent or sadistic crime have also confessed to carrying out cruel acts against animals.”

Peter Hepburn, chief executive of Cats Protection, a welfare charity, said: “We do receive calls from the cat-loving public who are extremely distressed by the alleged cruelty they have seen on the internet, including on YouTube. Some of these videos can be horrifying. Why people feel the need to be both cruel to these wonderful animals and then seek public attention of their actions is completely beyond me.”

A spokesman for YouTube said it relied on users to alert it to inappropriate clips, which were then removed.