Objective: Radiological examination of young fishes is often performed as a routine procedure with hatcheries and farms, aiming to evaluate the quality and health condition of fishes, before starting the on-growing stage. To date, radiology of fish was focused only on the skeletal system describing the incidence of
skeletal deformities (e.g., scoliosis and lordosis). However, a more detailed reading of the young fish radiographs also showed the presence of abnormalities in the abdominal viscera. In our study, we described and correlated all radiological findings and evaluated them with the growth rate of the examined fish population.
Method & Materials: In a population of 100,000 fish plain radiographs were performed. The fishes were sampled in groups of 30 individuals per radiograph and a total number of 10 radiographs per population were performed. The fishes had an average body weight of 1.8 grams, originated from the same rearing tank of a hatchery. The radiographs were performed using low penetration protocols. The growth rate of the examined fish population was measured for three subsequent months.
Results & Conclusion: Fishes with severe skeletal abnormalities also had discrete round opacities in the intestinal lumen. Those findings were present mainly in their last third part of the intestinal tract. In several cases a distention of the lumen and thickening of the intestinal wall were seen. Necropsy of the examined fish proved that those parts were composed of intestinal mucous, debris of epithelial cells, lipids and nonabsorbed feed, due to a croupous enteritis. The casts formed from the croupous material were particularly dense and, hence, were readily observable in radiographs. Fish individuals which had skeletal abnormalities accompanied by severe visceral pathology findings showed growth retardation even if their mortality rate was very low. However, the farming cost of those populations was considerably increased. As a conclusion, such radiological findings in the beginning of fattening suggest that the individuals need a proper food treatment which will eliminate the presence of enteritis and all side effects.