Heart is a Muscle

If you have only ever met heart on a yakitori menu, it can sound like an odd thing to put in a dog's bowl.

It isn't. Heart is the busiest muscle in the animal, and using it is part of a broader idea: when you take a wild deer, you use the whole animal, not only the prime cuts.

That is the ethic Nagano's game processors work by, and it is the one behind our meal topper, VENISON + APPLE. The heart in our recipe comes from the same wild sika deer (ニホンジカ [nihonjika, Japanese sika deer]) as the muscle meat.

An organ that behaves like meat

Anatomically, the heart is an organ. In your dog’s meal, it functions like meat.

It adds a deep flavour, the meat is dark red, dense and close-grained. It is firmer than a steak but clean and mild, without the strong note liver carries.

Heart naturally contains taurine, an amino acid concentrated in muscle tissue, together with vitamin B12, heme iron and riboflavin. Coenzyme Q10, a compound present naturally in meat, occurs in its highest amounts in heart tissue.

A prized cut for people, too

Japan has never treated the heart as waste. As ハツ [hatsu], it is one of the more sought-after skewers in yakitori and horumon [offal] cooking, valued for a firm, clean bite and a deep, savoury flavour. Cultures from Peru to the British Isles have their own versions of the same idea.

Heart is the gateway cut of eating more of the animal precisely because it is so meat-like.

The care is the quality

Wild game has to be handled quickly for food consumption, and organs faster than the rest.

Our deer are processed the same day they are taken, at a licensed facility in Nagano, and butchered by the same method used for venison prepared for people. Every animal is recorded: where it was taken, when, and by whom. That is what makes a clean, food-grade heart possible from a wild animal.

Nagano's game industry works to the prefecture's Shinshu gibier hygiene guidelines (信州ジビエ衛生管理ガイドライン), and our venison comes from a processor operating to that standard.

We include heart in VENISON + APPLE because it belongs there: a dense, flavourful, whole-food muscle that shines in taste and provenance. Our recipe uses a single source of wild protein: deer, and only deer.

Spooned over your dog's usual meal, nothing is wasted and nothing is hidden.

____

Karuizawa Harvest makes whole-food meal toppers for dogs. We're based in Karuizawa, Nagano. For more on what goes into VENISON + APPLE, and news of our autumn 2026 release, leave your email below.

Notes & sources

• Heart composition (taurine, CoQ10, B12, iron; heart as a proxy from beef/venison data): USDA FoodData Central · taurine values, Spitze et al. 2003, J Anim Physiol Anim Nutr, UC Davis (PDF)

• Heart classed as muscle meat in whole-food feeding: Perfectly Rawsome