Prevalence and impact of cestodes and protozoan Haemoproteus columbae in urban pigeons, first parasitological insights in New Valley, Egypt.

Abstract

This study aimed to conduct a comprehensive survey of parasitic infections among pigeons (Columba livia domestica) in the urban area of El Kharga, New Valley Governorate, Egypt. A total of 107 pigeons (77 males and 30 females) were examined for various intestinal and blood parasites during the period from May 2023 to July 2024. Intestinal parasites identified included five species of cestodes, while blood parasites included one species of protozoan, Haemoproteus columbae. In males, 53 samples (68.3%) were found infected with cestodes, with two exhibiting severe infection characterized by cestodes exceeding 19 cm in length, suggesting a novel species that causes intestinal spasm. Six samples (7.79%) were infected with Haemoproteus columbae. Among females, 16 samples (53.3%) were infected with different cestode species, and three samples (10%) were infected with Haemoproteus columbae. Two newly identified Raillietina sp. 1 and Raillietina sp. 2, were characterized based on their morphological features. Raillietina sp. 1 exhibits a U-shaped scolex surrounded by two rows of rose-shaped hooks, in contrast, Raillietina sp. 2 possesses a simple, unspecialized scolex with a round to conical shape and lacks a distinct neck. Histopathological examination of Haemoproteus columba infected lung sections revealed endothelial lining rupture due to merozoite invasion. In addition, liver sections showed congestion and irregular schizonts resembling liver sinusoids. These histological alterations demonstrate significant tissue damage and indicate a deterioration in pigeon health associated with parasitic infections. The identification and prevalence of cestodes and Haemoproteus columbae in the blood were determined using light microscopy. This study revealed many changes in the organs of urban pigeons (Columba livia domestica) in El Kharga and its surrounding regions through histopathological effects for the first time.