Prevalence of Gastro-Intestinal Parasites in Pigeons of District Jhang-Pakistan

Domestic pigeons (Columba livia domestica) are kept by humans all around the globe (Salem et al., 2021). The population density of feral pigeon is about one pigeon per 10-20 city dwellers (Vidyanagar, 2020) while the estimated worldwide population of the pigeons ranges between 165 to 330 million pigeons heads (Haag-Wackernagel and Bircher, 2010). Pigeons are not only reared as pets but also for food, ornamental and recreational purposes. That’s why they become pets in domestic, commercial and public places (Al-Barwari and Saeed, 2012). However, their faces constitute the main cause of environmental pollution (Sari et al., 2008). A single pigeon may produce about 10-12kg of feces annually on public places including historic buildings causing health issues to humans and livestock (Haag-Wackernagel, 2005; Haag-Wackernagel and Bircher, 2010).

Although, pigeon is not considered an endangered bird species, however its excessive hunting might produce a risk of its extinction (Adang et al., 2009). Pigeons feed on grains but also eat insects and worms (Jha, 2017). So, they can never be neglected as a potential carrier of different protozoa and helminths (Bogach, 2021). Pigeons do not relocate, however if they are permitted, they may return from longer distances to their nests due to their home loving nature. So, they might be infected by numerous pathogens and parasites that may be transmitted to their flocks (Opara et al., 2012). These birds are the main cause of zoonotic infections closely associated with humans whereas figuring out how common intestinal parasites are in these birds could be crucial to enhancing public health (Qi et al., 2011). Nevertheless, these birds are often neglected in terms of disease investigation and associated further research (Qamar et al., 2017). Exposure to huge burden of parasites may cause severe health issues or mortalities in affected birds (Sivajothi and Reddy, 2015).

Avian coccidiosis is the most significant protozoal disease of birds around the world that is caused by one or more of the seven birds-infecting Eimeria species (Haug et al., 2007; Kumar et al., 2014). Eimeria species survive for longer time in the oocysts as oocysts are source of infection when excreted in the feces of infected bird (Latif et al., 2016), so its utmost important to control this disease. Capillaria is also an important infection of pigeons (Dar et al., 2013). Different endoparasites including coccidia are usually present in their droppings (Dovč et al., 2004). Gastrointestinal parasites are under-investigated in birds in which capillaria species was the most prevalent parasite, with these, Ascaridia species and coccidial oocysts are also reported (Tietz Marques et al., 2007). Hence, such investigations offer the essential implications for managing the risk of zoonotic disease transmission among birds and its effects on veterinary practitioners, birds, and the general public’s health (Qamar et al., 2021). Therefore, the current study was performed to identify the fecal parasites of pigeons in Jhang district through different simple laboratory methods. The reported prevalence of parasitic diseases would greatly help in the improvement of possible control strategies. Investigation on the distributions of the different parasitic diseases will support the clinicians to properly treat and give awareness to the fanciers about suitable control measures.

Fresh fecal samples (n = 1800) of pigeons were collected in the plastic bags from the local shops and home fanciers of district Jhang. Two hundred collected samples were thrown out because of an artifact that occurred during transportation. All the remaining viable samples (n = 1600) were analyzed through different parasitological techniques including direct smear inspection, sedimentation and flotation techniques.

For direct smear analysis, 0.5 gram of fecal samples were mixed in 10 ml of normal saline. Following that, the debris was removed by filtering the suspension through a sieve. Then, a thin smear was made by the strained material (two drops) using glass slide and a coverslip. The slide was observed under the light microscope (Nikon, Model Eclipse E200LED; Nikon Corporation, Tokyo Japan) for the identification of oocysts (Greiner, 2008). The samples positive by direct smear investigation were further recognized through sedimentation and flotation methods.

Sedimentation method was done as proposed by (Latif et al., 2016) in which 3 grams of fecal sample were mixed in distilled water and subsequently filtered. Thereafter, centrifugation of the filtrate was done for 2 minutes at 1500 rpm (251.55 x g). Then, we discarded the supernatant and one drop of the sediments was placed on the clean glass slides to detect the parasitic oocysts under the light microscopy setup. The flotation method was carried out as proposed by (Faust et al., 1938). Counting of eggs per gram (EPG) was done by means of McMaster method (Foreyt, 2013).

Statistical analysis was accomplished using Quantitative Parasitology 1.0 (QP1.1) software (Reiczigel et al., 2019). We calculated the prevalence values (percentage), mean abundance and mean intensity following previously employed statistical methods (Rózsa et al., 2000).

Overall, 890 samples were positive out of total 1600 analyzed pigeon samples. One protozoan (Eimeria spp.) and one Helminth (Capillaria spp.) parasites were recorded in the examined bird samples. Moreover, the prevalence of Coccidia (70.7%) was higher than that of Capillaria spp. (15.7%). While, the prevalence of mixed infection (Eimeria spp. + Capillaria spp.) prevalence was (120/890) 13.4% (Figure 1 and Table 1). Besides, the EPG of Coccidia and Capillaria were estimated as 750 and 700, respectively.

Poultry birds are reared at poultry farms with all the hygienic measures and proper vaccination against different infections. However, the pigeons are inhabited in the open environment, their feed is unhygienic and there is no vaccination plan available for these birds. Several protozoa can potentially infect the digestive system of the pigeons (Toure et al., 2023). There are different endopartasites i.e., nematodes, cestodes and protozoa that might cause the reduced growth, less egg production, increased susceptibility to different diseases and high mortality in the pigeons. Therefore, this study was designed to diagnose the parasitic infections in pigeons through fecal examination. The results obtained in this study indicated the incidence of Eimeria and Capillaria spp. in pigeons. The proportion of the infections in the pigeons were 51% for Eimeria spp. and 46% for Capillaria spp.

Different researchers have reported different prevalence rates of coccidia and capillaria spp. in pigeons. Akram et al. (2019) reported 100% prevalence of Eimeria spp. in pigeons (Latif et al., 2016) also reported high prevalence of Eimeria spp. in pigeons that correlates with the present study. Herein, EPG was recorded at a moderate level of infection (700 for Eimeria spp. and 600 for Capillaria spp.) because of moderate temperature and humidity in November, those are not very favorable for parasitic infections. Similar findings were reported by (Qamar et al., 2017). In this present study, the findings of temperature and humidity with relation to level of infection are similar to the findings of (Parsani et al., 2014), who reported that nematodal infection was found at moderate level when the temperature was low. Whereas, high level of infection was attributed to monsoon weather (June to September) and the lower infection rates were recorded during summer season (February to May). Moreover, the prevalence and level of parasitic infection is influenced by the epidemiological factors such as sex, age, and breed (Djelmoudi et al., 2014).

Coccidia are the common pathogenic parasites in pigeons (Reddy et al., 2015). Dovč et al. (2004) examined 139 pigeons for the most common parasitic diseases. Eimeria and Capillaria spp. were documented in 71.9% and 26.6% of the examined dropping samples. Hence, the prevalence of both coccidia and capillaria spp. is comparable to the present study. In contrast, (Mushi et al., 2001) found coccidia oocysts in 40.0% and Ascaridia columbae in 30.0% of the examined fecal samples that is very high prevalence in comparison with the current study.

Table 1: Values of fecal parasites in sampled pigeons (Columba livia).

*Calculations of Percentage Prevalence of infected bird. No. of birds (infected)/total no. of birds examined (infected and non-infected) × 100. **calculation of mean intensity. Total no. of parasites within infected host/total no. of infected birds with that parasite. ***calculation of mean abundance. Total no. of individual parasites in infected host/total no. of hosts examined (infected and non-infected).

Moreover, protozoa (mostly Eimeria sp.) were noticed in 86.05% of the free-living pigeons while 20.93% of the birds were infected by mixed parasites that were almost similar as detected herein (Tietz Marques et al., 2007).

In another prior study of 132 fecal samples of pigeons, overall prevalence of gastrointestinal parasites was 72.7% including Ascaridia colombae (33.3%), Eimeria spp. (31.0%), Capillaria colombae (17.4%), Raillietina (9.0%) and mixed infections (31.8%) (Sivajothi and Reddy, 2015). This study coincides with the findings of capillaria spp. and mixed infection reports of the current investigation. While, the prevalence of coccidia spp. was low as compared to the present findings. However, the low prevalence of Capillaria spp. was recorded by (Sari et al., 2008) that is analogous to the present study. Furthermore, the previously reported prevalence of 26% for Capillaria spp. (Ghosh et al., 2014) is also consistent with our studies.

The present study revealed that pigeons were infected with various kinds of endo-parasites along with mixed infections. This was a preliminary study for identification and prevalence of parasites in the pigeons. Our findings have showed that the parasitic infestations might vary from area to area and species to species as the temperature and environment have the significant role for the parasitic infections. The prevalence of these infections in pigeons would be better identified by sophisticated molecular techniques. Necessary prevention and control programs are necessary to alleviate the risk of infection in pigeons. Furthermore, proper management practices and public awareness are the other strategies to stop the spread of pathogens from pigeons to the other livestock.

The authors greatly acknowledge the assistance of the Parasitology Lab staff for the accomplishment of these experiment.

This initial investigation was carried out in a specific location to determine the gut parasite frequency in pigeons in the district of Jhang. The findings will help to improve management of certain parasitic disorders, public education, and the application of practical control measures.

MFQ supervised the entire work and wrote manuscript. ARA, FY, TB and TH helped in planning of the experiment. IL, ARA helped in the analysis and refining the manuscript. IL, FY, and TB helped in statistical analysis of data. TH helped in collection of data.

The authors have declared no conflict of interest.