Histopathological alterations in bullfrog juveniles fed commercial rations of different crude protein levels

Abstract

The relationship between the quality of dietary crude protein and health of bullfrog juveniles (Lithobates catesbeianus) was evaluated by necropsy and histopathological examination of animals. The histopathology results showed that animals fed different feeds, regardless of CP levels, presented lymphocytary hepatitis, colitis and flattened microvillosities; kidneys with areas of tubulonephrosis and renal tubule calcification; myocarditis and cardiac muscular fiber dissociation. Such injuries suggested a degenerative nutritional process, with development of inflammatory processes spread to all the organs. These findings suggested that the animals had been fed with proteins of low biological value, indicating, apparently, poor feed quality, that harmed the health of the frogs and, consequently, their performance. Complementary studies are necessary to understand the biochemical behavior of the bullfrog in its second phase of life, supplying data for a better understanding of the nutrition of these animals.