GASTROINTESTINAL PARASITES IN CAPTIVE AND FREE-RANGING BIRDS AND POTENTIAL CROSS-TRANSMISSION IN A ZOO ENVIRONMENT

Wild Animals in Captivity: An Analysis of Parasite Biodiversity and Transmission among Animals at Two Zoological Institutions with Different Typologies

We have conducted a 10-year-long coprological study of the animals housed in two zoological institutions (ZooAquarium and Faunia, Madrid, Spain) to assess the parasite biodiversity, prevalence, and their relation with host class, diet, and enclosure type (soil type and level of isolation from wild fauna). A total of 4476 faecal samples from 132 mammal species and 951 samples from 86 avian species were examined. The results indicated that only 12.8% of avian species had parasites at least once during the study period, whereas 62.1% of mammal species tested positive. Predominantly, protists (Entamoeba, flagellates, and ciliates) and nematodes (mainly Trichuris) were identified in the findings. Carnivorous species were primarily infected by nematodes, while herbivorous and omnivorous species were mainly infected by protists. The number of infected herbivorous and omnivorous species was significantly greater than carnivorous species. Differences were observed based on soil type (artificial, natural, mixed) and isolation level (isolated/accessible), but these differences were not statistically significant. Several parasites (Entamoeba spp., Giardia spp., Balantidoides coli, Trichuris spp.) could potentially be transmitted between humans and some mammals and birds. Regular animal analyses and a personnel health program in the institutions would minimise transmission risks between zoo animals, wildlife, and humans.

A Cross-Sectional Survey of Gastrointestinal Parasites in an Ornithological Garden

Captive birds in collections may be infested with a wide range of parasites. Globally, information on parasitic infections and their health implications in ornithological collections are scarce. In the present study, the prevalence of parasitic infections in an ornithological garden in Tehran was investigated. Samples (n = 109) from various bird species were collected. Direct wet smear, sedimentation, flotation with Sheather's sugar, and modified Ziehl-Neelsen and Giemsa staining were used for parasite screening. Parasites were identified in 57 (52.3%, 95% confidence interval [CI] 42.9-61.7) samples, with protozoans being the most frequently observed organisms, including Cryptosporidium species, Eimeria species, Isospora species, Trichomonas species, and Histomonas species. Helminths were observed in 29 (26.6%, 95% CI 18.3-34.9) of the samples and included strongyles, Capillaria species, and Raillietina species. Ectoparasites were rarely recovered, but 2 species were identified: the poultry shaft louse (Menopon gallinae) and the fowl tick (Argas persicus). Free-ranging birds were significantly (P < 0.001) more likely to have parasites in their feces than caged birds. Fecal parasitic infections were order dependent and more prevalent in the Anseriformes and Galliformes (P < 0.05). The frequency of gastrointestinal parasites was notable in the investigated collection. In open natural bird gardens, such as in the present study, the probable transmission routes and sources of the parasitic infections are most likely via the free-ranging avian species. It is wise to recommend regular screening of the birds in these gardens to improve preventive control measures. Additionally, parasite genotyping should be considered to clarify our understanding of the epidemiology of zoonotic and nonzoonotic parasites.

Prevalence of gastrointestinal parasitic infections in wild mammals of a safari park and a zoo in Bangladesh

In safari parks and zoos, wild animals are kept mainly for recreational purposes. Animals in these enclosures are also crucial for the education, research, and conservation aspect. To ensure better management and good health of wild animals in captivity, it is essential to monitor the occurrence of gastrointestinal (GI) parasitic (helminths and protozoa) infections. The current investigation was undertaken to investigate the prevalence of GI parasitic infections in wild mammals at Bangabandhu Sheikh Mujib (BSM) safari park and Chattogram (CTG) zoo of Bangladesh. A total of 72 individual faecal samples were collected from 25 species of wild mammals. Routine qualitative (e.g. direct smear, sedimentation, and flotation) and quantitative (e.g. McMaster technique) tests were performed to identify the eggs or oocysts of helminths and protozoa. Results demonstrated that wild mammals of both BSM safari park and CTG zoo were infected with a total of 17 genera/species of helminths and protozoa. The overall prevalence of GI parasitic infections in wild mammals of both zoological parks was 65.3% (95% confidence interval [CI]: 53.14-76.12), whereas it was 72.4% (95% CI: 52.76-87.27) in the BSM safari park and 60.5% (95% CI: 44.41-75.02) in the CTG zoo. In both zoological parks, infection with nematodes was more frequent compared to other helminth into the wild mammals. The herbivores were more infected with GI parasites than carnivores and omnivores of both BSM safari park and CTG zoo. The mean eggs/oocysts per gram of faeces was the highest in the carnivores compared to herbivores and omnivores of both enclosures. The findings of the current study demonstrated that wild mammals of both BSM safari park and CTG zoo suffered from various GI parasitic infections. Regular monitoring along with proper therapeutic measures may reduce the severe consequences of GI parasitic infections in captive wild animals.

WormWatch: Park soil surveillance reveals extensive Toxocara contamination across the UK and Ireland

BACKGROUND

Toxocarosis is a globally distributed zoonotic disease, but sources of infection are not well documented over large geographical scales. To determine levels of environmental contamination, soil from 142 parks and recreational areas across the UK and Ireland was assessed for the presence of Toxocara.

METHODS

Toxocara ova (eggs) were isolated from soil samples by sieving and flotation and then enumerated. Individual eggs were isolated and imaged, and a subset was characterised by species-specific PCR and Sanger sequencing.

RESULTS

Characteristic Toxocara-type eggs were found in 86.6% of parks, with an average of 2.1 eggs per 50 g of topsoil. Representative eggs were confirmed as Toxocara canis by Sanger sequencing, with many eggs containing developed larvae, hence being viable and potentially infective. Positive samples were more common, and egg density was higher, in parks with greater perceived levels of dog fouling.

LIMITATIONS

Samples were collected at a single timepoint and with limited spatial mapping within parks. Further study is needed to discern spatiotemporal differences within parks and recreational areas.

CONCLUSION

Toxocara is widespread in soil in public parks, indicating a need for further efforts to reduce egg shedding from pet dogs. Standardised methods and large-scale surveys are required to evaluate risk factors for egg presence and the impact of interventions.

A Comparative Study of Mini-FLOTAC With Traditional Coprological Techniques in the Analysis of Cetacean Fecal Samples

Free-ranging cetaceans are considered sentinels for the marine ecosystem's health. New and non-invasive methods have been set up for the collection of fecal samples from free-ranging big whales at sea, permitting to gain an excellent epidemiological picture of parasitic infections in wild populations. To select the best protocol to be used for copromicroscopic examination in cetaceans stool samples, we evaluated the sensitivity of two commonly used techniques, i.e., a sedimentation-floatation method and the Mini-FLOTAC through validation by helminth isolation from the digestive tract. For this aim, gastrointestinal content and fecal samples were collected during necropsy from 44 cetaceans, including bottlenose dolphins (Tursiops truncatus), striped dolphins (Stenella coeruleoalba), sperm whales (Physeter macrocephalus), Risso's dolphins (Grampus griseus), Cuvier's beaked whales (Ziphius cavirostris), pilot whale (Globicephala melas), and fin whales (Balaenoptera physalus). Helminths were recovered through washing and filtering of the gastrointestinal contents and morphologically identified. Copromicroscopic examinations were performed on formalin-preserved fecal samples, using a sodium nitrate, sodium thiosulphate, and sucrose solution (s.g. = 1.450) for both methods. Helminths belonging to 9 taxa (i.e., the trematodes Synthesium tursionis, Synthesium delamurei, Campula palliata, Braunina cordiformis, Pholeter gastrophilus, the nematode Anisakis sp., cestodes of the family Tetrabothriidae and the acanthocephalan Bolbosoma sp.) were isolated. Eggs referable to the same taxa, with the exception of cestodes, were found in copromicroscopic analyses. Sensitivity of the Mini-FLOTAC method appeared higher or equal for all taxa, proving superior to the sedimentation-flotation method for the detection of all except Anisakis sp. The concordance of the two tests indeed revealed a moderate to perfect agreement (kappa values 0.42–1). Not excluding the limitations inherent to the techniques themselves, explanations for false-negative results at copromicroscopy could be linked to parasite-related factors, including prepatent infections, low parasitic burdens, or intermittent egg shedding. Notwithstanding these limitations, this study evidenced that the Mini-FLOTAC protocol approximates more accurately the composition of the gastrointestinal helminthic community of cetaceans from copromicroscopic examination, providing at the same time a quantitative estimation.

Prevalence of major nematodes and human factors that affect infection in the zebra dove in a closed cage system

Background and Aim:

Roundworms cause infections in the avian population that lead to illness and poor production. The singing zebra dove is an economically important animal in the Indo-Malay region. The prevalence of these parasitic groups in zebra doves is unknown. This study estimated the prevalence and associated human risk factors of gastrointestinal nematode infections in zebra dove farming.

Materials and Methods:

A cross-sectional survey was conducted from January to April 2021. The study was conducted on 184 doves in three zebra dove farms. Fecal samples were collected from pooled zebra dove droppings. Major proportions and infection intensity of gastrointestinal nematodes were morphologically identified and morphometrically investigated. Associated human factors were assessed through the interview surveys among farmers.

Results:

Results showed that 36.96% of the zebra doves were infected. The primary nematodes were Ascaridia galli (34.78%), Heterakis gallinarum (6.52%), Trichostrongylus tenuis (2.17%), Syngamus spp. (4.35%), and Amidostomum spp. (2.17%). The primary human factors that contribute to parasitic infection were poor hygiene, food contamination with parasites, and inappropriate deworming.

Conclusion:

There was a high prevalence of gastrointestinal nematodes in the zebra dove in the close cage system. Human factors played key roles as risk factors, and improves farming management will help reduce parasitic infections. However, these nematodes may contribute to poor health status and poor productivity of zebra doves. Further extensive studies on clinical signs and pathological changes should be conducted.

A Proposed Safari Park in a Subtropical Forest in Northeastern Bangladesh Will Be Detrimental to Native Biodiversity

Biodiversity in tropical and subtropical forests are at high risk of decline due to rapid anthropogenic development. Planned activities that potentially benefit communities near forests are often undertaken at the expense of forest biodiversity. Recently, the Government of Bangladesh released plans to develop a safari park in Lathitila forest in northeastern Bangladesh. This mixed evergreen, stream-fed, trans-border forest harbors 26 globally threatened species. The proposed plan aims to bring several exotic game animals such as the lion (Panthera leo), spotted hyaena (Crocuta crocuta) and cheetah (Acionyx jubatus) to be maintained in captivity. Additionally, exotic bird aviaries, gardens, a dolphinarium, a marine aquarium exhibit, and a carp pond have been proposed for construction. Here, we (i) summarize some of the key attributes of safari parks and the misconceptions associated with them; (ii) highlight some of the planned development activities of the proposed safari park; (ii) list the threatened species found in the area, and (iii) explain why establishing a park in the area would be detrimental the region’s biodiversity. We urge the government to abandon the plans to develop a safari park and suggest that the area be brought under formal protection for the benefit of biodiversity conservation.

Improving the sensitivity of gastrointestinal helminth detection using the Mini-FLOTAC technique in wild birds

High-performance-validated tests are essential for successful epidemiological monitoring, surveillance of parasitic infections, and comparative studies in wildlife populations. The Mini-FLOTAC is a novel flotation-based technique for the sensitive detection and quantification of gastrointestinal parasites that is recently being explored for use in wildlife. A limitation of any flotation-based copromicroscopic method is the selection of the flotation solution (FS), which might influence the performance of the test. However, no study has compared the influence of using different FS in the Mini-FLOTAC technique for parasite detection in wild birds. Here, we evaluated the diagnostic performance of the Mini-FLOTAC in three waterbird host species using two widely used FS: saturated salt (NaCl; specific gravity 1.20) and saturated zinc sulfate (ZnSO₄; specific gravity 1.35). One hundred fresh fecal samples were analyzed for parasite fecal egg counts (FEC). Regardless of the host species, fecal samples evaluated with the Mini-FLOTAC method using ZnSO₄ resulted in a significantly higher detection rate and higher FEC of strongylid, capillarid, cestode, and trematode parasites, than samples analyzed with the NaCl solution. Our concise study demonstrated the importance of using an appropriate FS for the identification of parasite eggs in wildlife species, especially in hosts with an expected aggregated distribution and low parasite load such as waterbird hosts. The higher analytical sensitivity of the Mini-FLOTAC technique achieved with ZnSO₄, and its applicability to fieldwork, highlights this method as a promising tool for the quantitative surveillance of parasite infections in wild bird populations.

Parasites of domestic and wild pigeons in the south of Ukraine

Pigeons are closely related to human life and are both a source of food and object for hobbies and sports. Parasitic diseases of birds are the main reason for their growth retardation, reduced productivity and viability. The article presents the results of studying the prevalence of trichomonosis, cestodes and nematodes among the population of wild and domestic pigeons in the south of Ukraine. According to the results of the conducted researches it is established that in the south of Ukraine endoparasitoses of domestic and wild pigeons are quite widespread, and all species of this bird are carriers of Trichomonas gallinae. At the same time, the highest rate of Trichomonas infection was recorded in Columba palambus and C. livia domestica, and the overall infestation of males is higher by 4.4% compared to females. It was determined that domestic pigeons C. livia domestica were infested with trichomonosis (27.5%) and nematodes (Ascaridia columbae, 57.1%), C. palambus – trichomonosis (32.1%) and cestodes (Raillietina spp., 82.4%), Streptopelia turtur – cestodes (Raillietina spp., 12.5%) and S. decaocto – cestodes (Raillietina spp., 71.4%) and nematodes (Heterakis gallinarum, A. columbae – 33.3% and 44.4% respectively). The overall rate of infestation of pigeons with cestodes was 28.4% and the incidence in males was higher by 3.9% compared to females. It was found that the most common species among pigeon cestodes is Raillietina spp. In addition, 22.9% of pigeons are carriers of nematodes (H. gallinarum, A. columbae and Capillaria spp.). Continuous monitoring of pigeon parasites is necessary because they, in most cases, come into contact with other species of poultry and are a source of general invasion. In terms of further research, it would be promising to study the prevalence of helminthic infestation among wild migratory birds.

HEALTH SCREENING OF THE EUROPEAN ENDANGERED SPECIES PROGRAM CAPTIVE POPULATION OF THE PINK PIGEON (NESOENAS MAYERI)

The population of the Mauritian pink pigeon (Nesoenas mayeri) fell to fewer than 20 individuals in the 1970s. Following intensive conservation efforts, the free-living population is now estimated to be 470 individuals. However, because of the population bottleneck the species remains at risk of extinction because of genetic loss and inbreeding depression. A European captive population was established in 1977 and a European Endangered Species Program (EEP) was formalized in 1992. As birds in the EEP captive population possess unique alleles not observed in the surviving free-living birds, the EEP management plan recommends transferring EEP birds to Mauritius to improve genetic diversity. Health screening of the current EEP population to identify circulating pathogens was performed. Forty-two birds from three collections in the United Kingdom and one in Jersey were screened for a wide range of pathogens, present clinically or subclinically, including important viruses, bacteria, protozoa, and helminths. Eleven birds tested positive for at least one pathogen: Trichomonas spp. (5), Yersinia kristensenii (2), Yersinia aleksiciae (1), coccidial oocysts (3), and strongyle ova (3). None of the positive birds showed overt signs of clinical disease, although two birds with Trichomonas spp. had suboptimal body condition. Genotyping of one Trichomonas gallinae sample revealed a type-C strain (low pathogenicity). The results from this screening will contribute towards a disease risk assessment, to create a pre-export protocol for translocation of captive EEP birds to Mauritius.

Free-ranging avifauna as a source of generalist parasites for captive birds in zoological settings: An overview of parasite records and potential for cross-transmission

Captive birds in zoological settings often harbor parasites, but little information is available about the potential for free-ranging avifauna to act as a source of infection. This review summarizes the gastrointestinal parasites found in zoo birds globally and in seven common free-ranging avian species [mallard (Anas platyrhynchos), Eurasian blackbird (Turdus merula), common starling (Sturnus vulgaris), Eurasian jackdaw (Corvus monedula), house sparrow (Passer domesticus), European robin (Erithacus rubecula), and rock dove (Columba livia)] to identify the overlap and discuss the potential for cross-species transmission. Over 70 references were assessed, and papers spanned over 90 years from 1925 to 2019. A total of 60 studies from 1987 to 2019 met the eligibility criteria. All examined free-ranging avifauna harbored parasite species that were also reported in zoo birds, except for the European jackdaw. Parasites reported in captive and free-ranging birds include nematodes (Capillaria caudinflata, Dispharynx nasuta, Ornithostrongylus quadriradiatus, Strongyloides avium, Syngamus trachea, and Tetrameres fissispina), cestodes (Dicranotaenia coronula, Diorchis stefanskii, Fimbriaria fasciolaris, and Raillietina cesticillus, Sobolevicanthus gracilis), trematode (Echinostoma revolutum), and protozoa (Cryptosporidium baileyi). Although no study effectively proved cross-transmission either experimentally or by genetic analysis, these parasites demonstrate low host specificity and a high potential for parasite sharing. There is potential for parasite sharing whenever determinants such as host specificity, life cycle, and husbandry are favorable. More research should be carried out to describe parasites in both captive and free-ranging birds in zoological settings and the likelihood of cross-infection. Such information would contribute to evidence-based control measures, enhancing effective husbandry and preventive medicine protocols.

Accuracy and precision of McMaster and Mini-FLOTAC egg counting techniques using egg-spiked faeces of chickens and two different flotation fluids

Faecal egg counting techniques (ECTs) are useful tools for assessing anthelmintic efficacy and selecting hosts resistant to parasite infection. McMaster (MM) is one of the most commonly used ECTs, but it suffers from low sensitivity and precision. Mini-FLOTAC (MF) has been proposed to replace MM, but so far has not been evaluated for gastro-intestinal nematode infections in chickens. This study compared sensitivity, precision, and accuracy of MM and MF with two trials using egg-spiked faecal samples ranging from 50-1250 eggs per gram of faeces (EPG). In addition, effects of two flotation fluids with different specific gravities (SG), namely salt (SG = 1.20) and sucrose solutions (SG = 1.32), on accuracy and time-spent for both ECTs were evaluated. Overall sensitivity based on the composite reads across all EPG-levels was 97.1 % for MM and 100 % for MF. MF was, however, more sensitive (P = 0.003) or tended to (P = 0.087) be more sensitive than MM at only the lowest EPG-level (i.e. 50 EPG) using one of the duplicate reads, whereas there was no significant difference at any EPG-level using composite reads. Overall average precision of MF (79.5 %) was higher (P < 0.001) than that of MM (63.4 %) across all EPG-levels. Precision of MM increased from 22 to 87 % with increasing EPG-levels from 50-1250 EPG. Corresponding precision estimates for MF ranged from 76 to 91 %. Overall recovery rate of MM (74.6 %) was significantly higher (P < 0.001) than that of MF (60.1 %). There was no significant difference in recovery rate of spiked-eggs among different EPG-levels (P = 0.833). Recovery rate of MM ranged from 64 % to 79 % across different EPG-levels, while it ranged from 54 % to 64 % with MF without an interaction between ECT and EPG-level (P = 0.701). It took more time (P < 0.001) to process (prepare and read) samples with MF than with MM using the same flotation fluid. The sugar solution tended to (P = 0.100) increase egg-recovery with both ECTs, while increasing (P < 0.001) time-spent for processing the samples. Our data collectively suggest that MM is less sensitive than MF only at around minimum detection level of MM when using unrepeated reads. We conclude that McMaster is faster, relatively more accurate but less precise than Mini-FLOTAC. The sugar solution with higher SG increases accuracy of both techniques at the expense of increased labour time.

The resistance of Eimeria spp. to toltrazuril in black grouse (Lyrurus tetrix) kept in an aviary

The black grouse is a critically endangered species in Europe. Aviary breeding and re-introduction programs have contributed to the reinstatement of black grouse populations. Parasitic diseases can influence the species' behavior, choice of habitats, and survival rates. Protozoa of the genus Eimeria are the most prevalent parasites in black grouse. The aim of this study was to evaluate the effectiveness of toltrazuril (TOL) against Eimeria spp. in black grouse kept in an aviary. Eimeria spp. oocysts (mean OPG for all birds = 7,047.84; SD = 5,625.05) were detected in feces samples in a routine parasitological examination. Parasitic infections were treated with toltrazuril Baycox 2.5% (Bayer, Leverkusen, Germany) at 1 ml/1 l H2O administered per os with drinking water twice a day for 2 d, 12 h/24 h. High oocysts counts persisted upon the second parasitic examination. Therefore, the birds were divided into 3 groups in 3 existing aviaries. Toltrazuril was administered according to the same protocol, and its uptake with drinking water was monitored. A parasitological examination conducted 5 d later revealed the presence of parasites, and the TOL dose was increased to 3 ml/1 l H2O. When oocysts were detected in a successive exam, the TOL dose was further increased to 5 ml/1 l H2O. The increase in TOL dose did not eliminate parasites, therefore, the treatment was discontinued. The fecal egg count reduction test (FECRT) revealed that 1 ml of TOL reduced fecal oocysts counts (OPG) by 0.02%, the second application of the same TOL dose reduced OPG by 0%, 3 ml of TOL reduced OPG by 0%, and 5 ml of TOL reduced OPG by 65.7%. The applied doses of TOL did not induce significant differences in the fecal oocysts counts of any of the identified species of coccidia. The results indicate that the coccidia species infecting black grouse have natural resistance to TOL.