Taurine is an amino acid that both dogs and cats require for health. For cats, it is an essential amino acid because their bodies cannot synthesize it, so it must be acquired from the diet. Dogs however, can synthesize taurine from two other amino acids, methionine and cysteine (which are found in meat). For cats, taurine is necessary for brain, nerves, eyes, heart, digestion, immune function and fetal development. For dogs, taurine is needed for eyes, reproduction, bile acid (for fat digestion) and for healthy heart. Dilated cardiomyopathy (DCM) in dogs and cats is associated with inadequate taurine levels.
Taurine naturally occurs in meat and many companies add extra taurine to their canned or kibbled foods as up to 50% can be lost during the cooking process.
If you are looking for an extra source of taurine to add to your pet’s diet, here is a list of products that you can add as food toppers or treats. Ingredients used in a canned or cooked product will have more taurine loss than a freeze dried or raw product.
Taurine amounts listed in mg per 100g below are extracted from this study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813349/ (unless otherwise noted). Amounts are approximate due to natural variations in food.
Clams, scallops, krill, shrimp, oysters, squid
Some of these ingredients can be difficult to find in products, however there are various freeze- dried and dehydrated treats as well as canned foods containing shellfish.
Scallops (raw): 827.7mg per 100g
Squid (raw): 356.7mg per 100g
Clams (raw): 240mg per 100g
Clams (canned): 152mg per 100g
Oysters (fresh): 70mg per 100g
Mussels (raw): 39.4mg per 100g
Sardines, salmon, capelin, tuna
Raw whole fish is a great treat to feed your pet! Alternatively, you could feed a freeze-dried fish snack as many types of fish are available in treat form such as fish skin rolls, freeze dried fish treats (whole or parts), dehydrated whole fish, fish flakes, etc. Dogs Naturally Magazine reports that the average fish contains 36 mg of taurine per ounce (if fed raw).
Here are some more exact amounts:
Whitefish (raw): 113.9mg per 100g
Tuna (canned): 41.5mg/100g
Tuna (chunk light): 39mg/100g
Cod (frozen): 31mg/100g
Meat and Poultry
Raw (frozen) and freeze-dried sources are readily available forms of meats. Dark poultry meat is higher in taurine than light meat. Organ meats are also a good source of taurine.
Turkey (dark meat raw): 306 mg/100g
Turkey (dark meat roasted): 299.6mg/100g
Chicken liver (raw): 110mg/100g 
Chicken (dark meat raw): 82.6mg/100g
Beef liver (raw): 68.8mg/100g
Beef heart (raw): 63.2mg/100g
Lamb (dark meat raw): 43.8mg/100g
Beef (raw): 43.1mg/100g
Beef (broiled): 38.4mg/100g
Turkey (light meat raw): 29.6mg/100g
Chicken (light meat raw): 17.5mg/100g
Turkey (light meat roasted): 11.1mg/100g
Taurine supplement for pets.
NOTE: This article is not meant to replace the advice of your vet or pet professional.
“The potential protective effects of taurine on coronary heart disease” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813349/