Philippine Animal Welfare Society (PAWS)
Two South Korean nationals and several Filipinos were arrested in the Friday raid at a two-hectare farm in the city of San Pablo, just south of the capital Manila, the Philippine Animal Welfare Society (PAWS) said.
Many of the dogs were severely injured, with ripped ears and tongues, including 20 that needed to be euthanised, it said.
"This appears to be a large operation and these South Koreans need to be punished," PAWS programme director Anna Cabrera said.
Those arrested were part of the same South Korean group whose operations were busted in December in a nearby province and who later posted bail, PAWS said. About 240 dogs were also rescued in that raid.
"Too many animals have already suffered, and criminals are becoming bolder, taking only two months after arrest to get back into their illegal operations once they have posted bail," the group said as it urged tougher laws to protect animals.
Those found guilty of animal cruelty can be jailed for between six months and two years, but suspects can go free on bail as the often-lengthy legal process continues.
PAWS said many of the dogs in the latest bust were not properly fed and sheltered, and showed scars and wounds from recent fights. The contests are broadcast online to a betting audience.
A picture released by PAWS on its Facebook page showed one emaciated dog chained to a tree in open grounds. In the background, steel drums were used as dog kennels.
Police were not immediately available for comment.