Histodiagnosis of heterakidosis in chickens

Abstract

The purpose of the research is to study pathology findings in heterakidosis in broilers.

Materials and methods. The study used pathological material (cecum, liver) from 8 laying hens aged one year. Organ samples were delivered to the Pathology Sector in 10% buffered formalin. They were fixed for 36 hours and examined histologically using paraffin embedding. Semi-automatic Thermo Scientific equipment was used to process tissue samples. Histologic specimens were stained with hematoxylin and eosin. The specimen histoarchitecture was assessed with an Axio A1.0 microscope; photographs were taken using the AxioVision software.

Results and discussion. Visual assessment of the pathological material revealed thickening of the distal cecum while the liver samples had no signs of pathology. It was found that Heterakis spp. was about 1 cm long; helminth eggs were oval-shaped and had a strong, uniform shell; their size was 49 × 26 micrometers in the mean. When dwelling in the cecum, Heterakis spp. causes atony of the distal cecum wall, and development of inflammatory and necrotic processes in the intestinal mucosa, which promotes active growth of bacterial flora, accumulation of bacterial byproducts and intoxication. In places where the helminth is localized, eggs accumulate and a risk of Histomonas spp. infection increases, namely, amoebic (in the intestinal lumen) and spherical (in the intestinal mucosa) forms of the protozoan were identified. It was not possible to differentiate Histomonas spp. in assessing the histological specimens of the liver from the infected birds. In diagnostics, we should consider the great similarity of morphological characteristics of Heterakis spp. and Ascaridia spp. eggs.