Parasites of cattle egrets (Bubulcus ibis) and the associated haematological and biochemical changes

Abstract

Parasitic diseases play an important role for wild animals and it is recognised as a significant factor in the successful conservation of endangered species. Diagnosing parasite infection and load in free-ranging populations traditionally is done via necropsy or coproscopy. Forty cattle egrets (Bubulcus ibis) were captured and used for this study. The birds were examined for parasites and associated ectoparasites were collected and identified. Gastrointestinal content of each bird was also examine for adult and eggs of different helminthes and protozoan cysts while blood smears were examined microscopically to identify the different haemoprotozoa associated with the birds. The haematological parameters and serum biochemistry profile of these birds were also evaluated.

Menopon gallinae was the only ectoparasite seen with a prevalence of 52.5%. The endoparasites observed include Ascaridia galli with the highest prevalence 14 (35%), Heterakis spp 7(17.5%), Trichostrongylus tenuis and Capillaria spp having the same prevalence 5(12.5%), Fascioloides magna 4(10%) and Syngamus trachea with 3(7.5%) had the lowest prevalence. Haemoproteus spp 9(22.5%) was the most prevalent haemoparasites observed with Leucocytozoon spp having a prevalence of 4(10%) while Plasmodium spp had the least prevalence of 3(7.5%). Eighty percent of the cattle egrets had at least one of the different endoparasites while 52.5% had ectoparasites and 40% had haemoparasites. There was a 22.5% prevalence of the combined co-infection of at least one each of the different endoparasites, ectoparasites and haemoparasites species in the cattle egrets. The risk of a co-infection of only endoparasites was found to be 20% while the infection with only ectoparasites and haemoparasite was found to be 2.5% in both cases. However, 92.5% of the cattle egrets had at least one of the different parasites while a combined infection of both Ectoparasite and endoparasite had the highest co-infection prevalence (25%). The study also showed that there was a significantly higher risk of co-infection of the different types of parasites in cattle egrets. There were significant differences in the haematological parameters and the serum biochemistry profile of the infected cattle egrets compared to the uninfected birds.

This study suggests that cattle egret when living near poultry pen could serve as a reservoir host for the transmission of parasitic diseases. Further research on parasite host interaction of wildlife birds is warranted to determine their possible role in the biological transmission of diseases.

Keyword: Wildlife, Cattle egrets, parasites, haematological parameters, serum biochemistry