if the liver is healthy then give it raw,but only in moderation,id mix it with some beef mince or tripe,just watch out,if theyre not used to it then expect a fecking mess if you give em too much,my dogs always eat raw but one very cold winter i decided to cook the dogs some liver,in the morning when i went to let them out,i couldnt believe it, it looked like the dogs had been decorating their run using oxtail soup by the fecking christ it stunk never again