MADRID, June 28 (Xinhua) -- Spanish police have said a video featuring a police dog "performing" cardiopulmonary resuscitation (CPR) is actually a stunt.

"No dog could ever perform CPR on a human being," Madrid Municipal Police spokesman Fernando Rodriguez said Tuesday.

"Poncho (the police dog) was trained to do this number for school visits, he doesn't actually know how to perform CPR," the spokesman added.

The 42-second video showed a policeman pretending to faint, and a police dog quickly rushed to him, jumping up and down on the chest of the "unconscious" man, even resting its head against the man's neck, apparently checking for a pulse.

The dog's well-trained acts were described by Madrid police in a tweet as "heroic acting" to "save the life of a policeman by giving him CPR," causing doubts among netizens about the effectiveness of such a rescue.

"They (dogs) don't have the strength to do so (conduct CPR) nor could they ever know how to check for a pulse," Rodriguez was quoted by Euronews as saying.

The video went viral since its being posted to Twitter on June 22. It has been viewed over 2.8 million times as of Thursday, garnering over 30,000 likes and 15,000 retweets.

Many people said they were impressed by the cuteness and loyalty of the dog.