No, this is not a joke-story as far as I can tell. It is a valid news story.
**Monkey gives first aid to electrocuted friend **- AP
NEW DELHI (AP) – Onlookers at a train station in northern India watched in awe as a monkey came to the rescue of an injured friend - resuscitating another monkey that had been electrocuted and knocked unconscious.
The injured monkey had fallen between the tracks, apparently after touching high-tension wires at the train station in the north Indian city of Kanpur.
His companion came to the rescue and was captured on camera lifting the friend’s motionless body, shaking it, dipping it into a mud puddle and biting its head and skin - working until the hurt monkey regained consciousness.
The first monkey, completely covered in mud, opened its eyes and began moving again.
There has been a recent thread on the rights of monkeys, something about not being judged as human but this is another heart-warming story.
I think there are pictures of the incident but not at the quoted story-link.