In a no-holds-barred social media confessional, Serena Williams has admitted to tasting her pet’s dog food.

Known the world over for 21 major tennis championship titles, Williams will now hope a reputation for sampling pet food does not overshadow her glittering tennis achievements.

In a lengthy series of videos posted to social media network Snapchat, Williams regaled the tale of how her Yorkshire terrier Chip had been served a dish of salmon and rice in her Rome hotel.

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Showing off the rather fancy pet food menu, Williams said she had been tempted by the look of the meal, saying “I ate a spoonful. Don’t judge me.”

She added, rather worryingly, that the food tasted “a little bit like a house-cleaner thing” – inadvertently suggesting this isn’t the first time she’s dabbled in the ill-fated consumption of not-for-human goods.

Watch Serena’s confession here

Williams said an urgent trip to the bathroom followed the dog chow taste test.

In a testament to her fortitude, Williams did not let any ill effects overcome her as she beat compatriot Christina McHale 7-6 (9/7), 6-1 in her Rome Masters quarter-final.

“I don’t think it’s consumable for humans. They should have wrote that,” Williams said.