A photographer was on hand and the photograph has appeared in the media.
The Daily Mail reported the protesters as being from People for the Ethical Treatment of Animals (PETA), Europe. The dung was popped off a truck outside Gordon Ramsay at Claridge's in central London.
The dung-dumping ocurred on the same day the show was to screen.
The F-Word was moved to issue a statement on the TV item, in which it said: "As part of the current series of Gordon Ramsay's F-Word, Channel 4's food magazine show, Janet Street-Porter features in a regular topical strand in which she presents her views on diverse food-related issues.
"Within this weekly feature on May 15 she will be exploring the viability of sourcing an alternative red meat food source - horse meat - and its relative nutritional merits compared with meat more traditionally favoured by consumers in the UK.
"Although perfectly legal to eat horse meat in Britain, the usual method of obtaining good quality product is to order from abroad.
"While the item includes a visit to rural France where sales of horse meat are rising, it does not extend to a discussion on animals being transported beyond their country of origin.
"Neither does it seek to suggest anything other than the paramount importance of the ethical welfare of any animals bred for consumption."