Not sure what size chunks, as I had to cut it smaller for my toothless cat. You do have to make sure not too feed too much heart, liver and kidney I think, maybe only once or twice a week - i bought kidney for them, but couldn't cut it!! So they had heart, liver and raw chicken, alternated over a week. I assume that if it is from a butcher, any kind will do, but you might find they are fussy over what animals it comes from