Ten of the 12 dogs seized in June from a South Richmond home in a dogfighting case had to be put down. Several of the dogs were overly aggressive, Richmond authorities said yesterday, and one dog had such a bad infection on its face that its skin fell off from scratching. New homes were found for the two survivors. In addition to the dogs, authorities found exercise equipment, medical supplies and other evidence of dogfighting at the home of Richard E. Robinson, also known as “Lil Richard,“ and his mother, Ardeller Morris, according to testimony yesterday in Manchester General District Court.