Search Results (52)

Highly pathogenic avian influenza (HPAI) H5N1 continues to pose a major threat to animal and public health. Since its emergence, clade 2.3.4.4b has become the dominant global lineage, associated with widespread outbreaks in Europe. This study aimed to characterise the H5N1 strains detected in backyard chickens in Serbia and investigate their phylogenetic and phylogeographic relationships with historical and currently circulating strains in Serbia and the broader region. Samples collected in 2024 were tested by qRT-PCR, and positive samples were propagated in MDCK cells. Whole genome sequencing of isolated virus was performed using the MinION Mk1C platform (ONT, Oxford, UK). Bayesian phylogenetic and phylogeographic analyses were conducted using BEAST X and SPREAD3 v.9.6. The results revealed three independent introductions of H5N1 into Serbia between 2020 and 2024. The spatiotemporal diffusion patterns confirmed both north–south and west–east viral spread from Northern and Central Europe into the Balkans. Additionally, Serbia was identified as a critical transit and divergence point in the regional transmission network, highlighting its role in the spread of H5N1 between Western and Eastern Europe. These findings underscore the importance of continued genomic surveillance in both domestic and wild bird populations to better understand and reduce HPAI spread. Full article

This retrospective study investigated the clinical presentation, diagnostic findings, and treatment outcomes in 419 backyard (pet) chickens admitted to the Service for Avian and Reptiles at the University of Veterinary Medicine Vienna from 1 May 2009 to 30 April 2019. The median age of the chickens was 1.5 years, with 83.8% being female. The majority (80.0%) presented with individual clinical issues, while 20.0% were diagnosed with flock diseases. The most common admission causes included unspecific clinical signs (57.3%), respiratory tract issues (18.4%), and locomotor problems (16.2%). Diagnostic imaging modalities such as ultrasonography, radiography, and CT scans revealed pathologies, including ascites, salpingitis, and skeletal system abnormalities. Parasitological examinations found a high rate of coccidia, Capillaria, and Ascaridia, while microbiological analysis identified Escherichia coli and Pasteurella multocida as common bacterial pathogens. The most prevalent diseases were upper respiratory tract infections (13.8%), egg peritonitis (9.9%), and soft tissue trauma (9.4%). Treatment outcomes showed that 67.5% survived to discharge, while 32.2% died or were euthanized. Surgical interventions were performed in 25.3% of cases, with the most common surgeries being salpingohysterectomy and wound debridement. This study highlights the wide range of health issues faced by pet chickens and emphasizes the importance of accurate diagnosis and targeted treatment in avian veterinary care. It also underscores the role of various diagnostic tools, such as imaging, pathogen detection, and histopathology, in addressing the health challenges of backyard chickens. Full article

With the aim to characterise the situation of the subsector, 25 poultry farms of the endangered native Utrerana chicken egg-laying-oriented breed (Gallus gallus Linnaeus, 1758) were surveyed in Andalusia (southern Spain) from 2021 to 2023 to investigate the structure of the farms, number of birds, health status, feeding management, and marketing of their products. It was found that the pace of foundation of Utrerana chicken farms accelerated from 2009, and most of the farms were concentrated in the province of Seville. Only 40% of the farms were legally registered. This breed is raised on small farms mainly dedicated to self-supply and raising birds for conformation and their aesthetic values, with limited marketing of eggs and meat, with facilities consisting often of one poultry house and one outdoor enclosure, and with a low number of laying hens per farm (53.5 on average). Current productivity is low, with an average of 139 eggs per hen per year, but hens have a long reproductive lifespan, averaging 4 years. The Partridge variety of the breed was the most common, followed by the Black-barred and Black varieties, while the White variety was very scarce, with only 31 specimens in total. Two-thirds of the farmers also raised other breeds of chickens, in addition to the Utrerana. The management and production system was free-range or backyard, with a certain proximity to the requirements of European Union-certified organic production with regard to stocking densities and generally with a good sanitary status, respect for welfare, and implementation of biosecurity measures on the farms. The feeding of the chickens was based on grazing in outdoor enclosures and on the provision of grains and compound feed, with 40.0% of farmers using commercial compound feed and half preparing feed themselves. Two-thirds of the farmers were affiliated with the National Association of Utrerana Chicken Breeders (“Asociación Nacional de Criadores de Gallinas Utreranas”, ANCGU, in Spanish); almost half of them took part with their birds in fairs and conformation shows, such as the Utrerana Chicken Fair held in Utrera (province of Seville) and more than a quarter of them have sold live birds of the breed at these fairs. The farmers carry out few promotional and advertising activities for their farms and products, predominantly by using social networks, and the market area reached is mainly local. In conclusion, this research has shown that the current alternative production system for Utrerana chicken is similar to that of the hens that originated the breed and consists of a few amateur farms, with a small number of birds, distributed mainly throughout the Andalusian countryside. It has been highlighted that there is a need for the livestock authorities to implement programmes for supporting farmers and promoting the breeding of this endangered avian breed, native to the Spanish zoogenetic heritage. Full article

Infectious laryngotracheitis virus (ILTV) is responsible for avian infectious laryngotracheitis (ILT), a highly contagious acute respiratory disease affecting chickens. However, there is limited information on ILTV and its distribution in Ethiopia, particularly in the southeastern region. The aim of this study was to establish the serological prevalence and molecular evidence in commercial and backyard chickens from Robe town, Southeastern Ethiopia. A cross-sectional study was conducted between December 2021 and June 2022, collecting 240 serum samples from randomly selected chickens belonging to eight kebeles (farms) using systematic random sampling. ILTV-specific antibodies were detected using a commercial indirect enzyme-linked immunosorbent assay (ELISA). From 240 serum samples, 26.7% were positive for ILTV antibodies. Logistic regression analysis identified the type of poultry farm (backyard) and the introduction of chickens from other farms as potential risk factors associated with ILTV exposure. Tracheal tissue and oropharyngeal and tracheal swabs were collected from suspected chickens for isolation and molecular detection. A total of six samples were successfully isolated in embryonated eggs (40%), with four of them verified with a specific PCR. These findings documented the presence of ILTV in the study area, which needs further insight to fully understand the actual spread of ILTV and quantify the damage caused to the poultry sector. Full article

Marek’s disease is caused by Mardivirus gallidalpha2, commonly known as Marek’s disease virus (MDV). This pathogen infects various bird species resulting in a range of clinical manifestations. The meq gene, which is crucial for oncogenesis, has been extensively studied, but molecular investigations of MDV in noncommercial South American birds are limited. This study detected MDV in backyard and ornamental birds from Brazil and Peru and characterized the meq gene. MDV was confirmed in all seven outbreaks examined. Three isoforms of meq (S-meq, meq, and L-meq) and two to seven proline repeat regions (PRRs) were detected among the sequenced strains. At the amino acid level, genetic profiles with low and high virulence potential were identified. Phylogenetic analysis grouped the sequences into three distinct clusters. Selection pressure analysis revealed 18 and 15 codons under positive and negative selection, respectively. The results demonstrate significant MDV diversity in the studied birds, with both high and low virulence potentials. This study highlights the importance of monitoring and characterizing circulating MDV in backyard and ornamental birds, as they can act as reservoirs for future epidemiological outbreaks. Full article

Backyard chickens often suffer from foot pad dermatitis (FPD), a condition exacerbated by poor husbandry, nutritional deficiencies, and obesity. Pressure-relieving bandages, commonly used in the treatment of FPD, are impractical for outdoor chickens as they quickly become wet and dirty, necessitating daily changes that are often unfeasible. This retrospective study explores the use of custom-fit silicone shoes created via 3D-printed molds as an alternative to traditional bandages. CT scans were used to design shoes adapted from a design used for birds of prey. Over three years, 16 chickens with varying degrees of FPD were treated. The results demonstrated that silicone shoes were an effective treatment for FPD, allowing outdoor activity and facilitating daily lesion care without frequent bandage changes. The median shoe-wearing period was 14 days, and most owners provided positive feedback. Despite some attachment issues, the occurrence of secondary pressure marks, and feather regrowth challenges, the silicone shoes offered better ventilation, reusability, and consistent pressure relief compared to traditional bandages. This study concludes that silicone shoes are a viable solution for managing FPD in backyard chickens, promoting faster healing and improving owner compliance. Full article

Isolation due to the COVID-19 pandemic has heightened daily tension, leading to stress and other illnesses. This research examined the impact of backyard activities on social and personal well-being, focusing on agricultural (gardens, vegetables, medicinal plants) and livestock activities (chickens, goats, sheep, cows). An exploratory study was conducted using a Likert-scale survey of 387 people, with 22 items covering economic growth, social well-being, and human development. The results showed that 50% of the respondents experienced pleasant emotions through sensory engagement with home gardens, leading to well-being, reduced anxiety and stress, better concentration, and improved family harmony. McDonald’s Omega (ω) value for item consistency was 0.964. Strong correlations were found between economic growth, social well-being, and human development with social and personal well-being, at 0.719, 0.819, and 0.812, respectively. These results are validated by an exploratory principal component factor analysis, which shows the correlation of the classes that integrate backyard activities on a principal axis. Backyard livestock activities had a lesser impact on personal and social well-being compared to agricultural activities, which were valued more for their economic and nutritional contributions. Thus, backyard activities, especially those involving home gardens, significantly enhance social and personal well-being alongside their economic and food benefits. Full article

The production of backyard chickens is an activity of great importance in the economy of rural families in Paraguay. The Rustipollos population was created through directed crosses between a commercial meat line and a local population belonging to non-specific breeds but phenotypically assimilated to Creole breeds. The aim of this study was to evaluate the genetic diversity, relationship, and structure of Rustipollos using 29 microsatellite markers. Analysis was performed on 50 Rustipollos animals and 926 other individuals as reference breeds/populations from Europe, Africa, South, and North America. A total of 318 alleles were detected, with a mean of 10.97 per locus. The polymorphic information content indicated that 80% of all loci were highly to moderately informative. Only two breeds/populations showed loci that did not deviate from the Hardy–Weinberg equilibrium. The results of genetic diversity indexes suggested moderate levels of genetic variability in Rustipollos population and low inbreeding level. The genetic differentiation index indicates a high genetic differentiation between populations. The results of the Neighbor-Net tree and STRUCTURE analyses indicate the existence of distinct gene pools, with some genetic relationships between Rustipollos, the commercial chicken strain, and south Spanish breeds. The Discriminant Analysis of Principal Components confirmed the observed genetic distances between breeds/populations. The results will be useful for sustainable use and official recognition of this population. Full article

Rural households all over the world rear backyard chicken mainly for their own consumption and, to a lesser extent, for barter trade. These chickens represent a staple dish with numerous culinary variations and a cheap source of protein. Although some Campylobacter species, and particularly Campylobacter jejuni and Campylobacter coli, have been associated with industrial poultry carcasses, studies concerning the ecology of this genus in rural households do not exist. To assess the prevalence of Campylobacter species in the tissues of backyard chickens, samples were collected from birds Gallus domesticus bred in households in the rural area of Epirus (Greece), and Campylobacter strains were isolated by quantitative methods at 37 °C and 42 °C. In total, 256 strains were identified, belonging to 17 Campylobacter species, with C. jejuni and C. coli being the most prevalent. From the four ecological parameters studied (size of the flock, presence of small ruminants in the same household, presence of other poultry species in the same household, and feeding leftovers of the household), the size of the flock and the presence of small ruminants and/or pigs in the same household mostly affected the distribution of these strains. To study the phenotypical resistance against 14 antibiotics, 215 strains were selected. The results showed a high prevalence of multidrug-resistance (MDR) strains extending to all classes of antibiotics. Further genome analysis revealed the presence of genes coding resistance (bla_OxA-61, tet(O), tet(A) cmeA, cmeB, cmeC, and gyrA (Thr-86-Ile mutation)), with the efflux pump CmeABC being the most prevalent. All antimicrobial resistance-encoded genes co-circulated, except for bla_OXA-61, which moved independently. The minimum inhibitory concentration (MIC) values of two out of three antibiotics (representing different classes) were reduced when the strains tested were exposed to carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a known efflux pump inhibitor. The same result was obtained with the addition of CCCP to the MIC values of bile salts. These results lead to the conclusion that Campylobacter species are present in an impressive diversity in backyard chicken tissues and that they exert a significant resistance to antibiotics, raising a potential danger for public health. Full article

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. Full article

Chlamydia psittaci, Chlamydia gallinacea, and Chlamydia abortus are the most common Chlamydia spp. in chickens and have a confirmed or suggested zoonotic potential. No recent data are available on their prevalence and impact in the Belgian chicken industry or in the recreational chicken branch. Therefore, a cross-sectional epidemiological study was executed where samples were collected from both factory-farmed and backyard chickens. More specifically, pharyngeal chicken swabs were obtained from 20 chicken farms, 5 chicken abattoirs, and 38 different backyard locations and were analyzed using species-specific Polymerase Chain Reactions (PCRs) for the presence of the three avian Chlamydia spp. To investigate their zoonotic potential, samples were simultaneously collected from 54 backyard chicken caretakes and 37 professional chicken caretakers or abattoir employees and analyzed using species-specific PCRs as well. This study confirmed the presence of DNA of all three Chlamydia species in both the chicken industry and backyard settings. Chlamydia psittaci was the most prevalent in the industry chickens (11.0%), whereas Chlamydia gallinacea was the dominant species in the backyard chickens (14.5%). Chlamydia abortus infections were more common in the commercial chickens (9.0%) compared to the backyard chickens (2.6%). The DNA of all three species was also detected in humans (3.9% Chlamydia psittaci, 2.9% Chlamydia gallinacea, and 1.0% Chlamydia abortus). Full article

Non-commercial chickens may be the third most numerous pets in Western countries. Yet, to date, there is limited research into their welfare or the care-taking practices and attitudes of their guardians. Using a quantitative questionnaire, this study investigated non-commercial chicken owners’ care-taking practices, attitudes, and relationship types with their chickens. Additionally, the study investigated barriers to optimizing non-commercial chicken welfare. Specific questions were asked regarding niche care-taking practices, including the use of Suprelorin^® implants. With 2000+ responses, this study found variable care-taking practices, yet largely positive attitudes towards chickens, and a “personal” (though not “close personal”) owner–chicken relationship, as defined by the Owner–Bird Relationship Scale. The Chicken Attitude Scale, Owner–Bird Relationship Scale, and Care Series scores were found to be correlated with each other, with coefficients ranging from 0.176 to 0.543 (p < 0.001). “Preventing commercial chickens from going to slaughter” was a key motive for chicken care by 56.1% of respondents, with 69.6% of respondents stating they cared for ex-commercial chickens. This study found a higher prevalence of reported poor health conditions and number of deaths relative to prior studies, and egg yolk peritonitis emerged as a leading health condition and cause of death. Moreover, 68.0% had not heard of Suprelorin^® implants, and only 6.3% used implants. Most (76.4%) chicken carers followed an omnivorous diet that includes chicken meat/eggs. The results reinforced previous findings concerning a need for more avian-specialist, locally available, and affordable veterinary care for chickens. Research into Suprelorin^® implants, rooster-specific care, and tailored requirements of caring for ex-commercial chickens is recommended. Full article

A complete genome sequence of an avian coronavirus (AvCoV; 27,663 bp excluding 3′ poly(A) tail) was determined using nontargeted next-generation sequencing (NGS) of an oropharyngeal swab from a backyard chicken in a live bird market in Arusha, Tanzania. The open reading frames (ORFs) of the Tanzanian strain TZ/CA127/19 are organized as typical of gammaCoVs (Coronaviridae family): 5′UTR-[ORFs 1a/1b encoding replicase complex (Rep1ab) non-structural peptides nsp2-16]-[spike (S) protein]-[ORFs 3a/3b]-[small envelop (E) protein]-[membrane (M) protein]-[ORFs 4a/4c]-[ORFs 5a/5b]-[nucleocapsid (N) protein]-[ORF6b]-3′UTR. The structural (S, E, M and N) and Rep1ab proteins of TZ/CA127/19 contain features typically conserved in AvCoVs, including the cleavage sites and functional motifs in Rep1ab and S. Its genome backbone (non-spike region) is closest to Asian GI-7 and GI-19 infectious bronchitis viruses (IBVs) with 87.2–89.7% nucleotide (nt) identities, but it has a S gene closest (98.9% nt identity) to the recombinant strain ck/CN/ahysx-1/16. Its 3a, 3b E and 4c sequences are closest to the duck CoV strain DK/GD/27/14 at 99.43%, 100%, 99.65% and 99.38% nt identities, respectively. Whereas its S gene phylogenetically cluster with North American TCoVs and French guineafowl COVs, all other viral genes group monophyletically with Eurasian GI-7/GI-19 IBVs and Chinese recombinant AvCoVs. Detection of a 4445 nt-long recombinant fragment with breakpoints at positions 19,961 and 24,405 (C- and N-terminus of nsp16 and E, respectively) strongly suggested that TZ/CA127/19 acquired its genome backbone from an LX4-type (GI-19) field strain via recombination with an unknown AvCoV. This is the first report of AvCoV in Tanzania and leaves unanswered the questions of its emergence and the biological significance. Full article

The conservation of threatened local livestock genetic resources involves characterising them to implement conservation strategies. The Utrerana is a Mediterranean-type chicken breed, included in the Official Catalogue of Livestock Breeds of Spain and in the Domestic Animal Diversity Information System (DAD-IS) of the Food and Agriculture Organization (FAO), native to south Spain created in 1926 by a farmer from Utrera (Seville province). It was selected for laying performance and with four plumage varieties (White, Black, Black-barred and Partridge), reaching average yields of 180 eggs per hen per year. It was widely used in commercial farming in the second quarter of the 20th century, being subsequently displaced in the second half of the 20th century by the spreading of the improved foreign breeds and lines. The Utrerana breed was reared from then on for its aesthetic values and in backyard systems, being endangered with a vulnerable local risk status (1822 birds in 2022 with an increasing trend) and having worsened its laying performance as selection for productivity ceased. The breed has received little attention from the research community. Therefore, this work aims to review the literature on the origin, selection, genetic and productive characterisation and status of the populations of the breed, as well as the conservation strategies. The Utrerana chicken is a polymorphic breed showing high genetic diversity, sexual dimorphism and morpho-functional differences among varieties. Currently, Utrerana hens start laying at 6 months of age, and a hen lays 94–121 high quality eggs (59–64 g) per year, showing seasonality. It is a slow-growing breed with mature weights of 2.4–2.6 kg for roosters and 1.9–2.0 g for hens. The Utrerana chicken breed is rustic and adapted to alternative farming systems. This review has identified research gaps to be filled, such as characterising the carcass and meat quality of the Utrerana chicken, and evidences the need to make efforts to promote the breed and expand its populations. Full article

Avian malaria and leucocytozoonosis can cause fatal diseases, whereas avian trypanosomiasis is reported to be harmless in chickens. Backyard chickens can be infected by several pathogens, including blood parasites, that may shed to industrial poultry production, with a consequently higher economic impact. This study aimed to investigate the presence of several blood parasites (Plasmodium, Leucocytozoon and Trypanosoma) in backyard chickens raised in Southern Thailand, using PCR-based detection and microscopic methods. From June 2021 to June 2022, 57 backyard chickens were sampled. Fresh thin blood smears were prepared from 11 individuals, and buffy coat smears were prepared from 55 of them. Both thin blood smears and buffy coat smears were used for microscopic analysis. Two nested PCR protocols that amplify a fragment of cytochrome b (cytb) and small subunit rRNA (SSU rRNA) genes were used to identify Haemosporida and Trypanosoma parasites, respectively. The number of positive samples was higher with the application of nested PCR than when buffy coat smears were used. Three new Plasmodium lineages (GALLUS47-49) and thirteen Leucocytozoon lineages (GALLUS50-62) were found. Trophozoites, meronts and gametocytes of Plasmodium gallinaceum (GALLUS01) were present in one thin blood smear. All thin blood smears revealed Leucocytozoon infections, but only three samples were a single infection. These three samples revealed the presence of fusiform host cell–parasite complexes, of which the morphological features resembled those of Leucocytozoon macleani (possible synonym is Leucocytozoon sabrazesi), while the cytb showed that this parasite is closely related to the lineage GALLUS06-07, described as Leucocytozoon schouteni. The Trypanosoma prevalence was 33.33%; it was present in only one of the thin blood smears, and it resembles Trypanosoma calmettei. This study showed the prevalence of a high diversity of Plasmodium (64.91%) and Leucocytozoon (89.47%) in Thai chickens. Both nested-PCR and buffy coat smear can be used as the diagnostic tool for the testing of Plasmodium, Leucocytozoon and Trypanosoma for parasitic control in backyard chickens and poultry farms. The information on the parasite species that can be found in chickens raised in Southern Thailand was also considered as the baseline information for further study. Full article