Connolly's Red Mills is the latest company to cease its sponsorship of greyhound racing.
It follows an RTÉ investigation into cruel treatment of the animals by some individuals.
Last week, the broadcast revealed that almost 6,000 greyhounds are killed each year in Ireland because they are not fast enough.
A previously unpublished report highlighted on the programme also found that 1,000% more pups are bred than the racing industry requires.
In a statement, Connolly's Red Mills, which is a manufacturer of animal feed products, says the welfare of animals is of their utmost concern.
It said a failure to address these "unacceptable activities" has led to its decision.
Its statement read: "Connolly's RED MILLS prides itself in providing the best nutrition for pets, working animals and elite sports animals.
"The welfare of greyhounds is of the utmost concern to Connolly's RED MILLS and the company is horrified by the completely unacceptable acts that were broadcast by RTÉ."
"No-one who cares about animals can condone the practices depicted in the broadcast."
Earlier this week, Barry's Tea and FBD Insurance confirmed they were ending their involvement with the industry.