I read that the Japanese are considering alternatives to tuna for sushi, owing to a shortage brought on by the worldwide popularity of the dish (and their own consumption).
At the Fukuzushi restaurant in Tokyo, Shigekazu Ozoe, said he might use red-coloured substitutes such as horse and deer if tuna supplies ran out, as he did in 1973 when a mercury poisoning scare meant customers refused to eat the fish.
“We tasted it, and horse sushi was pretty good. It was soft, easy to bite off, had no smell,” he told the New York Times.
I wouldn’t recommend it, unless you’re a vampire — the taste of blood is quite strong. I once had the privilege of trying both horse sashimi and beef sashimi in a small village in central Japan. In comparison with the beef sashimi, the horse sashimi was pleasant with a mild flavour; an acquirable taste. Beef sashimi was like chewing on an open wound.