Taurine: The Best Known Amino Acid

Taurine: The Best Known Amino Acid

Taurine is a topic I run across frequently, either people asking me questions or seeing it in various places on the internet.  Some of the things I’ve heard over the years are “taurine is needed to manage or treat heart murmurs” or “if you don’t add taurine to your dog’s or cat’s food you’ll kill them” to “I want extra taurine in my pet’s food”.

Taurine’s treated like a mysterious but reverent thing. Most don’t know what it is or where to find it, but we need some in the food. More is better. Way better. It’s obvious there’s an underlying misunderstanding of what taurine is, how it’s used by the body, and a lack of knowledge about amino acids in general.

Taurine became known in the last few decades when a large number of cats and dogs started developing health issues from commercial pet foods lacking sufficient taurine.  Most manufacturers have since fixed the taurine deficiencies in their foods.

The concern is valid. Taurine deficiency is serious for dogs and devastating for cats.  With a little more information you can make better diet decisions for your pet.

What Is Taurine

Taurine is an amino acid.  Amino acids are the building blocks of protein.  Being carnivores, the best amino acid sources for cats and dogs are from eating animal proteins like meat, eggs, and poultry.  Not plants.

Taurine is only present in animal proteins, not plant proteins e.g., pea or soy protein (one reason to avoid a vegan diet for cats).  While taurine is in all muscle meats, it’s especially concentrated in the heart muscles, eye/retinas, and brains.  If your dog or cat eats fresh, unprocessed muscle meat, it’s getting taurine — sufficient levels of taurine for the average animal.

A Bit More About Amino Acids

When you or your pet eat a protein, from either plant or animal source, it’s broken down into amino acids.  Mammals use 20 different amino acids to create protein in their bodies so they can grow and function properly (there are at least two additional amino acids but not part of this discussion).  Protein is used by your body to build and renew muscle, regulate immune function, create hormones, neurotransmitters, and more.

All 20 amino acids are important.  Some amino acids are manufactured by the body and others aren’t.  The ones that aren’t are classified as essential.  An essential amino acid means it can ONLY be obtained through diet: the amino acid must be eaten because the body can’t make it.  If a diet lacks one or more essential amino acids it prevents the body from creating protein.  It’s like baking a cake.  If you don’t have eggs, you can’t make a cake, even if you have plenty of every other ingredient.

Humans require nine essential amino acids in their diet, dogs require ten, and eleven for cats.  Taurine is non-essential for dogs and humans, but it is essential for cats.

You’re probably wondering if taurine is non-essential for dogs, how can they suffer from a deficiency?  Because most dogs make their own taurine from other amino acids, it’s been thought that they didn’t need dietary taurine.  Genetically some dog breeds have difficultly producing taurine: American Cocker Spaniels, English Setters, Golden Retrievers, Labrador Retrievers, Newfoundlands, and Saint Bernards. These dogs may need a special diet to avoid developing a deficiency that can come from low protein, high amounts of plant protein, overuse of grains, by-products, or high fiber diets.  This genetic issue in certain breeds was at the center of a recent taurine alert with commercial Lamb and Rice formulas issued by the FDA.

Effects of Low Taurine

For dogs, there are no symptoms specifically related to taurine deficiency.   A taurine deficiency can cause an enlarged heart, which leads to serious health problems.  Dilated Cardiomyopathy (DCM) is a form of heart disease in which the heart muscle becomes weak and the heart becomes enlarged. This results in poor heart function, leading to lethargy, anorexia, rapid and excessive breathing, shortness of breath, coughing, abdominal distention, and losses of consciousness.  

Symptoms of a taurine deficiency in cats often progress slowly, leading to blindness and heart failure. A cat’s eye health and vision will slowly start to decline, and it will become harder for the heart to deliver blood throughout the body. Because taurine deficiencies can become life-threatening, it’s important to ensure that your cat is receiving enough taurine.  

Keep in mind the vast majority of dry pet foods out there (kibble) contain little or no real meat, but instead use cheaper substitutes like plant proteins (corn gluten, wheat gluten, soy and pea protein), and by-products such as meat and bone meal; these are poor taurine sources.  Read the label on your pet’s food, not the price tag.

The good news is taurine-deficient DCM heart disease can usually be reversed in dogs and cats by supplementing taurine or moving to a high-taurine diet until recovered.  Taurine supplementation may slow or stop the progression of retinal degeneration, but is usually not successful in reversing the damage.

Taurine and Pet Health

Cats have some dietary requirements that are different from dogs and can develop nutritional deficiencies when fed diets formulated to meet the nutritional needs of dogs.   Unlike dogs, cats require dietary sources of vitamin A, arachidonic acid, and taurine which aren’t usually found in food formulated for dogs in kibble and canned sources. Cats also require higher quantities of fat and protein than dogs,  the amino acid arginine, niacin, and pyridoxine (vitamin B6).  The take-away is make sure to feed a species appropriate diet to avoid more than a taurine deficiency in your pet.

Fish contain high levels of taurine.  However, fish isn’t a natural diet protein for cats and feeding raw fish has hazards that must be avoided.  Being fed a fish-based diet will have nutritional holes for cats unless there’s proper nutrient supplementation or it’s part of a complete diet plan.  Absent that, a diet high in fish can lead to thiamine deficiency in cats and other issues depending on the type of fish and/or diet.

Meat is the best source of taurine in most cases for dogs and cats.  But not all meats and processing/preparation methods are the same.  Taurine is durable and can withstand most normal cooking temperatures (Stapleton PP, Charles RP, Redmond HP, Bouchier Hayes DJ. Taurine and human nutrition. Clin Nutr. 1997;26:103–8.).  However, when meat is processed into kibble much of the taurine is broken down by the high heat, destroying half or more of the taurine.  Dark meat is also a richer source of taurine, yielding about ten times more than white meat, and there is a difference overall between muscles/cuts-of-meat and specific animals (see chart). If you see taurine added to your pet’s food, run! It means the food is highly processed and the proteins are poor quality.

If you supplement taurine from artificial sources, make certain the taurine is in capsule form, not tablet, since tablets have binders that capsules don’t. Also make certain that taurine supplements do not contain any preservatives and no other supplements.

For your cat, AAFCO recommends 0.25g – 0.5g of taurine per 1000 calories.  Currently, the recommended dose of taurine in dogs has been extrapolated from cats.  Taurine is generally considered safe, with no known or documented toxicity. There are a few indications that excess taurine causes some health issues, but they haven’t been independently confirmed or widely reported.

Summary

To make sure your dog or cat gets sufficient taurine, you should feed raw or minimally processed meat.  These diets have significant percentages of highly digestible proteins providing ample amino acids, including taurine, to prevent conditions like DCM.  Adding heart and dark meat cuts to the diet will increase natural amounts of taurine.  Feed a species appropriate diet to not just avoid taurine deficiencies but other nutritional issues.

Taurine isn’t present from plant sources.  You can tell you’re feeding a diet high in plant proteins by looking for taurine supplementation on the label. If you see taurine listed pick another food because it’s highly processed and/or uses incomplete or poor protein sources. 

And finally, don’t forget there are other essential amino acids.  Even if you’re feeding an abundance of taurine, there could be a significant health impact you ignore the levels of the other 19.

All of the Fetching Foods products have adequate levels of taurine for each species.  Every Just Cat and Only Dog contains not just meat, but heart and liver — all natural, no supplementation. Taurine and the other essential amino acids are ideal in our products.

Fetching Foods is a top quality, nutritionally rich food for dogs and cats.  It’s made entirely with high-end, human-grade ingredients.  We offer raw, cooked, and custom options.  We are trained pet nutritionists, chefs, and herbalists.

Essential Amino Acids

Humans: The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

Dogs: The 10 essential amino acids are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine.

Cats: The 11 amino acids are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, and taurine.

Selected Taurine Amounts in Foods

Food Method of Preparation Mean Taurine Content mg/100g
Beef Raw 46.3

Broiled 38.4
Chicken dark meat Raw 169.6
Chicken light meat Raw 17.8

Broiled 14.5 
Turkey dark meat Raw 306

Roasted 299.6
Turkey light meat Raw 29.5

Roasted 11.1
Veal Raw 39.8
Pork, loin Raw 61.2

Roasted 56.8
Lamb dark meat Raw 43.8
White fish Raw 151.2
Shrimp, medium Raw 155.2
Mussels Raw 655.4
Oysters Fresh 396.7
Cod Frozen 31
Clams Raw 513.1

Canned 152
Octopus Raw 388
Scallop Raw 827.7
Squid Raw 356.7
Cow’s milk Unprocessed <0.5
Yogurt, low-fat plain
3.3
Pasteurized milk
6

Bibliography 

1. Pion PD, Kittleson MD, Rogers QR, et al. “Myocardial failure in cats associated with low plasma taurine: A reversible cardiomyopathy.” Science 1987; 237:764-768.

2. Earl KE, Smith PM. “The effect of dietary taurine content on the plasma taurine concentration of the cat.” British Journal of Nutrition 1991; 66:227-235.

3. Hickman MA, Morris JG, Rogers QR. “Effect of processing on the fate of dietary taurine in cats.” Journal of Nutrition 1990; 120:995-1000.

4. Hickman HA, Morris JG, Rogers QR. “Intestinal taurine and the enterohepatic circulation of taurocholic acid in the cat.” Advances in Experimental Medicine and Biology 1992; 315:45-54.

5. Freeman LM, Rush JE, Brown DJ, et al. “Relationship between circulating and dietary taurine concentrations in dogs with dilated cardiomyopathy.” Veterinary Therapeutics2001; 370-378.

6. Backus RC, Ko KS, Fascetti AJ. “Low plasma taurine concentration in Newfoundland dogs is associated with low plasma methionine and cysteine concentrations and low taurine synthesis.” Journal of Nutrition 2006; 136:2525-2533.

7. Ko KS, Backus RC, Berg JR, et al. “Differences in taurine synthesis rate among dogs relate to differences in their maintenance energy requirement.” Journal of Nutrition 2007; 137:1171-1175.

8. Fascetti AJ, Reed JR, Roger QR, et al. “Taurine deficiency in dogs with dilated cardiomyopathy: 12 cases (1997 – 2001).” Journal of the American Veterinary Medical Association 2001; 223:1137-1141.

9. Delaney SJ, Kass PH, Rogers QR, Fascetti AJ. “Plasma and whole blood taurine in normal dogs of varying size fed commercially prepared food.” Journal of Animal Physiology and Animal Nutrition 2003; 87:235-244.

10. Torres CL, Backus RC, Fascetti AJ, et al. “Taurine status in normal dogs fed a commercial diet associated with taurine deficiency and dilated cardiomyopathy.” Journal of Animal Physiology and Animal Nutrition 2003; 87:359-372.

11. Ko KS, Fascetti AJ. “Dietary beet pulp decreases taurine status in dogs fed low protein diet.” Journal of Animal Science and Technology 2016; 58:29-39.

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