Certification of swine herds as virus pneumonia-free.
D000818:Animals; D002568:Certification; D011014:Pneumonia / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases; D014777:Virus Diseases / Q000662:veterinary*
PNEUMONIA/veterinary; SWINE/diseases; VIRUS DISEASES/veterinary