The results of experimental invasion of laboratory rats by larvae of the nematode Eustrongylides excisus are presented in the article. The invasions were carried out by nematode larvae, which were selected from a ram caught in the Dnieper-Buhsky estuary. According to the results of ichthyopathological research, we found the larvae of nematodes, which in terms of morphometry and color differed from those described in the scientific works of a number of authors. Тhe larvae of E. excisus that we found in the ram from the Dnieper-Bug estuary. According to the results of the studies, changes in the clinical condition of the experimental animals were established: suppression of the general condition (I group of rats – 40, II – 53,3 and III – 73,3 %), loss of appetite (I group – 40, II – 66,6 and III – 80 %), signs of severe tenderness of the abdominal wall (group I – 13.3, II – 46.6 and III – 60 %), abdominal distension (group I – 20, II – 33.3 and III – 33.3 %), disorders of the function of the gastrointestinal canal (diarrhea) (group I – 33.3, II – 40 and III – 53.3 %). During the study, improvements in the clinical status of some rats were observed (group I rats – 50, II – 30, and III – 41.6%). During pathoanatomical dissection of the infected animals, signs of serous fibrinous peritonitis (group I – 6,66, II – 33,3 and III - 53,3 %), adhesion of the peritoneum leaf (group I – 6,66, II – 26,6 and III – 46,6 %), signs of gastrointestinal canal damage (group I – 26,6, II – 46,6 and III – 66,6 %), expressions of pathology of the chest cavity (group I – not detected, II – 26.6 and III – 40 %), pathological changes in the kidneys (group I – not detected, II – 13.3 and III – 26.6 %), and splenomegaly (group I – not detected, II – 20 and III –26,6 %). The E. excisus nematodes were established, which showed signs of vital activity: they were mobile, their activity increased during mechanical irritation. Quite often, nematode larvae were found dead. They were white or white-gray in color, the cuticle of the surface of the body had a slightly macerate and loose structure. Survival of parasites in the body of a non-specific host is 4.6 % in group I, 7.3 % in II group and 12.6 % in III group.
Eustrongylides excisus, nematodes, roach, experimental invasion, rats