Occurrence of Eimeria spp. and Intestinal Helminths in Free-Range Chickens from Northwest and Central Romania

Chickens raised in backyard free-range systems are confronted with a significant threat of parasitic infections. Among the parasitic agents, protozoa belonging to the genus Eimeria and helminths, including Ascaridia galli, Capillaria spp., Heterakis gallinarum, and Strongyloides avium, stand out as the most prevalent. The sampling protocol included sixteen localities in four counties within the Transylvania region of Romania. Fecal samples were collected from chickens reared in a backyard system. Fecal samples were screened for oocysts (O) and eggs (E) by flotation method, and their number per gram of feces (OPG/EPG) was calculated after counting them by McMaster method. Positive samples for Eimeria spp. were further analyzed by PCR (polymerase chain reaction) method to identify the Eimeria species. A total of 145 flocks were tested and the overall prevalence of infection was 53.1%. The most prevalent infections were with A. galli/H. gallinarum (25.5%), and Eimeria spp. (24.8%), followed by Capillaria spp. and strongyles. The mean OPG/EPG values were as follows: 63,577 for Eimeria spp., 157 for Ascaridia/Heterakis, 362 for Capillaria spp., and 1671 for Strongyle eggs. Identified Eimeria species were E. acervulina (41.7%), E. tenella (27.8%), E. praecox (16.7%), E. brunetti (16.7%), OTUy (operational taxonomic unit y) (8.3%), OTUz (operational taxonomic unit z) (8.3%) and E. mitis (5.6%). Intestinal parasites exhibit a high prevalence among chickens in backyard poultry flocks, and the presence of significant parasite burdens can adversely affect both productive and economic aspects. To the best of our knowledge, this is the first comprehensive study that aimed to analyze the prevalence of gastrointestinal parasites in chickens raised in a backyard free-range system in Romania, and the first report of OTUy species in Europe.

Two New Species of the Genus Heterakis (Heterakidae) from the Genera Echymipera, Isoodon and Perameles (Peramelidae), Bandicoots from Papua New Guinea and Australia

PURPOSE

To identify and describe any new nematode species of the genus Heterakis Dujardin, 1845 (Heterakidae Railliet & Henry, 1914) found in bandicoots (Peramelidae Gray, 1825) collected from Australia and Papua New Guinea and held in the South Australian Museum, Adelaide.

METHODS

All the relevant specimens registered in the South Australian Museum were examined as temporary wet mounts, after clearing in lactophenol, using an Olympus BH-2 microscope with differential interference optics. Measurements were made with an eyepiece micrometer and figures drawn using a drawing tube.

RESULTS

Heterakis balamukensis n. sp. was described from Echymipera kabulu (Lesson, 1828) collected from Balamuk station, Bensbach River, Papua New Guinea and Heterakis oweni n. sp. was described from Isoodon macrourus (Gould, 1842) collected from Papua New Guinea, and Queensland, Australia. Heterakis sp. females were identified from I. macrourus from the Northern Territory and Perameles pallescens Thomas, 1923 from Queensland, Australia. A key to the valid species of Heterakis from mammals is given.

CONCLUSIONS

The heterakid fauna of mammals now comprises eight species: the cosmopolitan species Heterakis spumosa Schneider, 1886 as well as H. balamukensis n. sp., H. fieldingi Smales, 1996, H. oweni n. sp. and H. sirawii Smales, 2016 from Australasia, H. dahomensis (Gendre, 1911) from Africa, and H. inglisi Gupta & Trevadi, 1982 and H. yamagutii Gupta & Trevadi, 1982 from India. Two species have been declared species inquirenda; H. equispicularis Uphadyyay, 2017 and H. verrucosa Molin, 1860, while H. rattui Ghambir, Gyaneswori, Tarnita, Indrani & Zenith, 2008 falls as a junior synonym of H. spumosa. No infections of the cosmopolitan species infecting rodent hosts, Heterakis spumosa Schneider, 1866, were found in bandicoots.

Cancerogenic parasites in veterinary medicine: a narrative literature review

Parasite infection is one of the many environmental factors that can significantly contribute to carcinogenesis and is already known to be associated with a variety of malignancies in both human and veterinary medicine. However, the actual number of cancerogenic parasites and their relationship to tumor development is far from being fully understood, especially in veterinary medicine. Thus, the aim of this review is to investigate parasite-related cancers in domestic and wild animals and their burden in veterinary oncology. Spontaneous neoplasia with ascertained or putative parasite etiology in domestic and wild animals will be reviewed, and the multifarious mechanisms of protozoan and metazoan cancer induction will be discussed.

Fenbendazole resistance in Heterakis gallinarum, the vector of Histomonas meleagridis, on a broiler breeder farm in South Carolina

Parasites are highly prevalent in poultry; thus, the management of parasites is a key component in the profitable production of poultry. The most common nematode parasite of poultry, Heterakis gallinarum, typically causes no direct pathology but is the vector of Histomonas meleagridis, a highly pathogenic protozoan parasite that causes blackhead disease. There are no approved treatments for H. meleagridis, making control reliant on controlling the helminth vector. In the United States, the benzimidazole anthelmintic fenbendazole (FBZ) is the only approved treatment for H. gallinarum. We were contacted by an industry veterinarian regarding clinical problems with histomoniasis despite frequent anthelmintic treatments. Given that we had recently diagnosed FBZ resistance in the closely related parasite Ascaridia dissimilis, we were interested to determine if H. gallinarum had also evolved resistance. An initial on-farm pilot study using 20 birds suggested that FBZ was poorly effective, therefore a larger controlled study was initiated. Heterakis gallinarum eggs were isolated from litter at the farm and used to infect 118 chicks. Treatment groups included a non-treated control, a label-, and a 2×-label dose of FBZ, with 36 birds per group divided into two replicates of 18 birds. Three weeks post-hatch, birds were infected with 150 embryonated eggs. Two weeks post-infection treated birds were administered either a label- or 2× label-dose of FBZ in water for five days (SafeGuard® Aquasol, 1 mg/kg BW). To increase the likelihood that all birds consumed the full intended dose, the dosage was calculated using 1.25 times the average body weight. One-week post-treatment, birds were euthanized, and parasites enumerated. There were no significant differences in worm numbers recovered from any of the three groups (p-value = 0.3426), indicating that both dosages of FBZ failed to provide the expected levels of efficacy. These data provide strong evidence that H. gallinarum has developed resistance to FBZ on this farm. Consequently, on this farm, or any farm with FBZ-resistant H. gallinarum, H. meleagridis will continue to cycle in an unrestricted manner despite administration of anthelmintic treatments. Given recent evidence of increasing problems with histomoniasis, and the fact that resistance was documented on the first farm we investigated, further investigations are needed to determine the prevalence of resistance in H. gallinarum on poultry farms. These data, when viewed together with our recent findings of FBZ resistance in A. dissimilis on multiple farms, suggest that drug resistance in ascarid nematodes may be an emerging problem in the US poultry industry.

Prevalence of gastrointestinal parasites in three groups of domestic poultry managed under backyard system in the Savanna subregion, Department of Sucre, Colombia

Objective:

To identify the prevalence of gastrointestinal parasites that affect the backyard poultry system in the Savanna region, Department of Sucre, Colombia.

Materials and Methods:

Fecal samples were collected from 860 native birds, both hens (Gallus domesticus), ducks (Anas platyrhynchos domesticus), and turkeys (Meleagris gallopavo), regardless of age and sex. Samples were processed using direct techniques with ZnSO₄ and indirect methods such as modified Sloss. Data were presented as frequencies, and the nonparametric odds ratio test was used for two independent samples.

Results:

A total of 77.3% (665/860) of the birds were infected with one or more species of gastrointestinal parasites. Among the nematodes, Capillaria spp. (45.6%), Ascaridia galli (18.4%), Heterakis gallinarum (59.4%), Syngamus trachea (38.9%), Tetrameres spp. (25.2%), and Strongylus spp. (12.2%) were recorded. The cestodes were Choanotaenia infundibulum (22.6%), Davainea proglottina (42.3%), Raillietina spp. (58.3%), and Hymenolepis spp. (54.7%), while only Eimeria spp. (90%) was recorded as protozoa.

Conclusions:

The study showed a high incidence of gastrointestinal parasite infestations, the most common species being Hymenolepis spp., Eimeria spp., Raillietina spp., and Heterakis gallinarum.

In addition to birds' age and outdoor access, the detection method is of high importance to determine the prevalence of gastrointestinal helminths in laying hens kept in alternative husbandry systems

The prevalence of gastrointestinal helminths was investigated in sixty-six commercial non-caged layer flocks. Twenty-nine flocks were housed indoors in aviaries or floor systems, nineteen flocks were kept in conventional free-range systems with outdoor access, and eighteen flocks in organic free-range systems. Flocks were investigated at end of rearing (mean age 17 weeks), peak of egg production (mean age 38 weeks) and before slaughter (mean age 74 weeks). Four different methods were applied to determine worm infestation. During necropsies, worm infestations were recorded and mucosal scrapings were evaluated for the presence of worm eggs. Faecal samples from each flock were investigated by simple flotation method and McMaster counting technique. No gastrointestinal helminths were found in pullets. During production, 87.9 % of the layer flocks were infected with at least one nematode species at the peak of production. The prevalence further increased significantly up to 98.5 % at the end of production (p=0.05). This increase could be ascribed mainly to infections with Ascaridia (A.) galli and/or Heterakis (H.) gallinarum which were most prevalent in all husbandry systems. Furthermore, their prevalence increased significantly with the age of birds (p=0.023; p < 0.001). With regard to the husbandry system, the prevalence of Capillaria spp. was significantly higher in flocks from outdoor systems compared to flocks that were kept indoors. Cestodes were only detected at the end of production with a prevalence of 15.2 % and significantly more flocks with access to outdoor run were found positive. Interestingly, H. gallinarum was found with a high prevalence indoor and in outdoor systems. Anthelminthic treatment did not impact the prevalence of nematode infections. Comparing four different methods for the detection of helminths it was revealed that their efficiencies varied depending on the worm species. Overall, the simple flotation method was superior to detect A. galli and Capillaria spp. This method proved also very efficient for the detection of H. gallinarum but the additional evaluation of the worm infestation during necropsy increased the level of prevalence. Cestodes were mainly found during necropsies when the worm infestation was evaluated. The detection of parasite eggs in mucosal scrapings from the intestines was the least effective method for all helminths. These findings lead to the recommendation to combine faecal investigations with an evaluation of the worm infestation during necropsy of at least five birds.

Protozoan and Helminth Infections of Aviary-Reared Alectoris rufa (Galliformes: Phasianidae) before Releasing for Hunting in the Czech Republic: Infection Dynamics and Potential Risks

Age-related dynamics of protozoan and helminth infections in the red-legged partridge, Alectoris rufa, were studied in an intensive breeding aviary in the Czech Republic before releasing birds for hunting purposes. Pooled fecal samples (n = 900) were examined over 3 rearing seasons (2012-2014). A total of 4 protozoan species, Cryptosporidium baileyi, Cryptosporidium meleagridis, Eimeria kofoidi, and Eimeria legionensis, and 4 helminths, Capillaria phasianina, Eucoleus perforans, Heterakis gallinarum, and Syngamus trachea, was found. The most common parasite was S. trachea (prevalence 20-26%) in dead birds (n = 99), which represents a high risk for breeders. Co-occurrence of protozoans and helminths indicated similarities in infection dynamics throughout the 3 breeding seasons. Mixed infections of Cryptosporidium baileyi and C. meleagridis with other parasitic species are reported for the first time. Our findings provide new insights into breeding of A. rufa and may help to improve the efficacy of disease control strategies and prevention, especially with the potential for spreading of parasitic infections to wildlife through released birds into open areas.

in Game Birds and Cage-Free, Floor-Raised Poultry in Pennsylvania

Histomoniasis is a significant disease of gallinaceous birds caused by Histomonas meleagridis. Transmission of this parasite is dependent on use of the cecal nematode Heterakis gallinarum. To define the host range of this nematode, cecal contents from 399 game birds and poultry, representing eight species, were examined for Heterakis spp. The majority of these species (five of eight) were infected with Heterakis nematodes. Heterakis gallinarum was detected in free-ranging wild turkeys (Meleagridis gallopovo), captive-raised ring-necked pheasants (Phasianus colchicus), chukars (Alectoris chukar), and domestic chickens (Gallus gallus domesticus), whereas H. isolonche was found in ruffed grouse (Bonasa umbellus). No Heterakis species were identified in the domestic turkey (Meleagridis gallopovo), American woodcock (Scolopax minor), and dabbling duck (Anas spp.) samples. Genetic characterization indicated that nematodes identified as H. gallinarum were present in two distinct clades. One clade of H. gallinarum sequenced from this study grouped with chicken-derived sequences from other countries. The other group of sequences consisted of a sister clade to a group of parasites morphologically identified as H. isolonche. Currently it is unknown if this group represents a genetic variant of H. gallinarum, a variant of H. isolonche, or a novel species. These results indicate Heterakis infection varies among poultry and game bird species but is common among select gallinaceous species in Pennsylvania.

Morphological characterization of nematodes of the genera Capillaria, Acuaria, Amidostomum, Streptocara, Heterakis, and Ascaridia isolated from intestine and gizzard of domestic birds from different regions of the temperate Kashmir valley

During a random survey of parasitisation of poultry birds of Kashmir, conducted for 3 years more than 300 poultry birds were randomly collected from different parts of the Kashmir valley and were examined for the helminth parasites. The most dominant group of parasites which was parasitizing the poultry birds was found to be the Cestode, whose prevalence in the infected birds was 76.9 %. Nematodes were found to be the second dominant group of parasites after cestodes with the prevalence of 70 %. Among the different species of nematodes Heterakis gallinae were found infecting almost all the birds autopsied. The highest intensity of H. gallinae might be because of the fact that it requires cockroaches, beetles and grasshoppers as intermediate hosts in addition of having a direct life cycle. Nematodes which were recovered from the intestine and gizzard of the birds belong to the genera Capillaria, Acuaria, Amidostomum, Streptocara, Heterakis, and Ascaridia.