Fish should be released from the bones. In the diets of dogs, especially diet, is used mostly lean and moderately fatty fish. To lean fish (3% fat) belong pollack, pollock, walleye, cod, hake, pike. Some species of fish (Merlano, hake, pollock, saithe, haddock, and others) contain trimetilaminoksid linking to stern iron and converting it into form. As a result, dogs and cats there is a severe form of anemia, change hair color. Boiling removes the negative effect of fish. When feeding fish in their raw form should be introduced into the feed chalybeate (Ferroanemin, Ferodex, etc.). The fish is usually divided into fat and white.
White fish such as cod, haddock, flounder European, hake and halibut generally contains less than 2% fat, whereas fatty fish such as herring, mackerel, sardine, pilchard, sprat, bluefish, salmon, European, trout and eel, can contain much more fat from 5 to 18% depending on time of year or stage of maturity of fish caught. In general, white fish in its composition is very similar to lean meats. Protein quality as high as vitamins A and D are generally either absent altogether or present in very small quantities. But the muscle tissue of fish contains enough iodine, and because the bones are often consumed together with meat fish, such food is much better balanced calcium and phosphorus. Fish as fillets boneless significantly depleted in calcium and phosphorus. Meats, oily fish contains vitamins A and D, and liver of fish such as cod and halibut, are particularly rich sources of fat-soluble vitamins.