Footage shows rescuers desperately trying to revive the dead animals, who remain limp and lifeless on the concrete floor.
Local authorities have said the breeder could face up to 90 years in prison after carrying the animals in a vehicle with no ventilation.
CNN Philippines reported 40 dogs were transported to a Beagle Fanciers Club Dog Show in Marikina, near the country’s capital Manila, by an exhibitor on 2 December.
A number of dogs were unconscious, dehydrated and dead when they arrived at the venue and taken to the nearest vet. Some died the next day.