Organ meats

Heart

Aside from energy, vitamins and minerals, the heart also contains amino acids, specifically large amounts of taurine. Muscle meat in general contains fairly high amounts of taurine, an amino acid which is necessary for healthy heart and eyes in cats. Generally, the amount of taurine in chicken meat depends on how much work the muscle does, with darker meat indicating harder-working muscles and a higher level of taurine. The heart, being the hardest-working muscle in the body, contains the highest amounts of taurine. In my research, I have not been able to find any evidence that cats can get too much taurine, as any excess is metabolized and excreted in the urine.³

The bottom line is that large amounts of chicken heart, seven or more per day, could provide more than the recommended nutrients for your cat. My recommendation would be to limit chicken hearts to no more than two to three per day. This way you can be confident that you are not providing your kitty with too much of any one nutrient.


Web MD

In response to a post about the importance of reading ingredient lists on cat food labels, Westcoastsyrinx said, “Personally I find that the organ meat is not an appropriate regular source of protein as the amino acids are not the same balance as muscle meat, and such parts as kidneys will contain all the toxic residue from the source of the meat.” Westcoastsyrinx makes some important points that I thought were worthy of further discussion.

When you think about it, organ meats, including the kidneys, liver, heart, etc., are a normal part of the feline diet. When cats kill mice or other prey items, they eat most, if not all, of the body, including the internal organs. In fact, many predators show a preference for these parts of the body over skeletal muscle, probably due to the fact that they are excellent sources of protein, vitamins, minerals, and other nutrients.

The following chart compares one ounce (28 g) of raw liver from cattle, raw kidney from cattle, and raw, grass fed beef (Source: nutritiondata.self.com):

As you can see, skeletal muscle is relatively higher in calories and fat per ounce, but is good source of omega-3 fatty acids and calcium. On the other hand, liver excels at providing vitamin A, vitamin K, iron, and phosphorus, and kidneys can provide high levels of vitamin A, vitamin C, vitamin D, calcium, iron, phosphorus, and sodium. My point is not that organ meats are superior to skeletal muscle; simply that they are a natural way to provide cats with many essential nutrients that might otherwise have to be added as supplements to a balanced feline diet.

Westcoastsyrinx is right that organ meats like the liver and kidney can concentrate toxic residues within their tissues because of their role as filters within the body, but when livestock is raised in a healthy manner this does not have to be the case. In my opinion, this is simply an argument in support of buying foods from companies that have a reputation for using wholesome ingredients, not for avoiding organ meats entirely since they can be such good sources of important nutrients for cats.

Organ Meats in Commercial Pet Treats

Organ meats are used in many commercial pet treats.

Unfortunately, most commercial pet treats contain inappropriate ingredients like grains, unnecessary fillers, rendered animal by-products, added sugar (sometimes hidden in molasses and honey), chemicals, artificial preservatives, and allergenic ingredients.

Heart, liver, kidneys, pancreas, gizzards and brains are probably the most common or more easily obtainable organ meats.
But you can also feed lungs, stomach, gallbladder, eyes, various glands (adrenals, thyroid, pituitary, etc), testicles, ovaries, etc.

• There are two approaches to feeding organ meat: 
  1. Feed organ meats in larger amounts twice per week.
  2. Feed organ meats every day but in smaller amounts
• Organ meats are a nutrient dense source of food and too much organ meat is not good. As an example, liver is high in oil soluble vitamin A (not to be confused with the vegetable source of vitamin A also known as beta carotene). If you feed too much liver then you will actually cause liver stones because liver stones are created when the body gets too much oil soluble vitamin A. In fact, the Inuit are well known for eating Polar Bear liver and as a result, a lot of Inuit suffer (especially in the past) from liver stones.
• If you choose option 1 and thus feed organ meats twice per week, then the organ meat should be approximately 50% of the meat source. So let's say, as an example, you were feeding 1 cup of meat. In this situation you would then use approximately 1/2 cup organ meat and 1/2 cup muscle meat.
• If you choose option 2 and thus feed organ meat every day then approximately 10% of the meat source should be organ meat. So let's say again, as an example, that you were feeding 1 cup of meat. In this situation you would add approximately 1/8 of a cup as organ meat and the rest as muscle meat.
• My personal favourite is heart because of its high taurine content and since it is usually available. 
  • Taurine is an essential amino acid.
  • A lot of people who have cats worry about not providing their cats with enough taurine. This is because taurine is an amino acid that is specifically needed by cats. In fact, many commercial pet foods now say on their packaging taurine added to help increase sales from concerned cat owners. But the reality is, to ensure your cat is getting enough taurine, all you need to do is feed raw meat!
  • Some vets will unfortunately use some fear tactics by saying you must make sure your cats are getting enough taurine when feeding a homemade diet. The reality is that the only reason why commercial pet foods say on their labels taurine added is because commercial pet foods are not a good source of taurine and thus taurine must be added. When you feed a wholesome raw meat diet then the taurine is naturally added by Mother Nature herself in the form of wholesome nutrition.
  • Any organ that has electrical activity is high and/or a concentrated source of taurine. This includes the heart, brain and eyes.
  • Although heart, brain and eyes are high in taurine, the reality is all meat contains taurine. When you feed muscle meat, there is also taurine in the meat, just not as high.
  • The feeding of eyes doesn't sound that appealing but many pets will enjoy eyes. Sometimes fish eyes are available.
  • It has been said that mice provide the highest source of taurine!
• Some butchers will sell brain. While not on the top of most people's list of things to buy, many pets do enjoy eating brain.