Kittens firing a cannon, a rabbit sniffing for drugs, attempts at humor on the fraught presidential campaign trail and a failed prank by Google competed for attention in the US on Friday.

As ever, the trick for April Fools' Day hoaxes was to try to be outlandish, yet faintly plausible.

The police department in Amherst, New York, unveiled a new crime-fighting scheme, showing an officer with a rabbit on its Facebook page.

"'Dusty' and his handler will be able to search vehicles and other small areas with greater accuracy," the department said.

National Geographic, following Playboy's decision this year to stop publishing photos of nude women, said it would no longer degrade animals by showing them naked.

The magazine's statement on the Internet was accompanied by a black and white photo of two kittens in jumpsuits firing a cannon.

There was some naked publicity in the form of bogus ads.

ThirdLove, a lingerie maker, partnered with DogVacay, a pet-sitting service, to unveil a line of dog brassieres.