my friend has amarican bull dog puppies 7of them they are weak,saliva coming out of their mouth diarea and vomiting 2 have suddently died witch we are sad about. he changed their food 2 days ago (brand Ror) and that's when he noticed they were not well.but not shure if thats the cause. what can be the cause of their sudden illness? and a cure for it. please help we don't want any more death these are beautiful puppies i think only 5 months old.

