Sliced-in-half calf heart
Prey hearts are devoured by most cats and dogs. Rich in minerals and vitamins, raw hearts are a necessary addition to any diet, raw or other. Hearts are part of the 80% muscle meat category if feeding the Frankenprey diet and are the hardest-working muscles in the body. Muscles that are used extensively are not only darker in color, due to extra mitochondria and myoglobin content, but also contain larger amounts of taurine.
Taurine is an amino acid required by the heart, the skeletal muscles, the large intestines, the central nervous system, and pretty much the entire mammalian body. Studies are showing that taurine supplementation decreases cholesterol levels, increases fat metabolism, and helps in the treatment of various heart conditions. This amino acid is a potent antioxidant and as important and vital as it is, canned and dry foods severely lack taurine.
Raw chicken hearts
It doesn't matter if you are feeding basic or premium canned/dry food. All of these are deficient in taurine. This came to wide media attention in the 1970s when thousands of cats and dogs were mysteriously dying of dilated cardiomyopathy. Others were developing blindness. It was later discovered that this was due to a taurine deficiency. Something as pure and simple as an amino acid robbed from a diet can easily lead to disease and death. Leave it to us humans to withhold vital essentials from ourselves and others. Unlike cats, humans and dogs can synthesize taurine from other amino acids and protein building blocks (although, studies are showing that dogs need more taurine than previously hypothesized). Taurine is found in muscle meats and is completely absent from grains and fillers commonly used in canned and dry foods. Not only is this amino acid lacked by grains, but these fillers prevent amino acid absorption, leading to further taurine deficiency. Grains in cat and dog food are diabolical---lacking essential amino acids and preventing amino acid absorption from scarcely present meat.
Excessive fat deposits on calf heart that we cut away before feeding
Today, pet food companies use diseased scraps of inedible, completely-deficient-in-taurine animal leftovers to bulk up the food content. They also use a shitload of cheap, mercury-filled tuna that robs cats and dogs of vitamin B1. Because the ingredients are so horrid and unappetizing to cats and dogs, they will coax them with artificial flavors. As far as taurine and other supplements are concerned, commercial pet food companies will add synthetic nutrients to canned and dry food. Taurine is easily degraded and deteriorates upon cooking, freezing, grinding, thawing, etc. (pretty much any handling). It is unstable and sensitive to change. The ingredient list may state taurine was added, but you can be certain the animals aren't getting a drop of it. Some veterinarians falsely believe and claim that certain feline and canine breeds are more prone to cardiac myopathy, but this may very well be the masking of long-term taurine deficiency. Some breeds require more taurine in the diet and without it, they develop cardiac myopathy. In these cases, taurine deficiency is to blame.
Raw turkey hearts
Darker raw muscle meat equals more taurine presence. Certain raw protein sources, like poultry, have taurine in abundance, while others (venison, rabbit, and lamb) are low in taurine. Raw prey hearts are the best sources of taurine; along with potassium, magnesium, iron, and selenium. They are also packed with B-vitamins and several amino acids.
Your takeaway: Hearts are part of the 80% raw muscle meat category of the Frankenprey diet, so they should be fed on a regular basis. Hearts are the hardest working muscles and they are full of taurine. Taurine is essential to cats and dogs and without it, they are predisposed to cardiac dysfunction and disease. Canned and dry pet food is severely deficient in taurine. Companies add synthetic taurine to canned and dry food that is easily degraded and never reaches the animal for nutritional benefit. You can be certain most cats and dogs are lacking this vital amino acid. Raw prey hearts are a perfect and optimal source of taurine; along with other nutrients. Like others organs, hearts are high in phosphorus and cholesterol and low in calcium, so it is important that the diet consists of 10% bones to make up the calcium portion of the diet.
When to feed: We feed the Frankenprey diet over a week's worth of meals. For us, we feed hearts once or twice a week; either as a meal or mixed with other Frankenprey parts. Some purchased raw mixes and grinds may contain prey hearts and we account for that.
How much to feed: The amount to feed depends on the animal's weight. Cats should eat 2-3% of body weight worth of raw food per day.
A 10lb hunter should eat 0.25lbs (4oz) of food per day to maintain weight. This equates to 2oz per meal if feeding twice daily. This is 28oz per week.
80% of 28oz is 22.4oz. So, a 10lb animal should eat 22.4oz of raw muscle meat per week. Don't let hearts be the only muscle meat offered. They are too rich to be fed the complete 80% of the diet. Feed hearts 1-2 times a week; 3 times if the animal is anemic. You can make raw hearts a complete meal or mix them with other raw food you are feeding that day.