Free-ranging dogs match a human's preference in a foraging task.

Social learning is a mechanism used by many species to efficiently gain information about their environment. Although many animals live in an environment where members of other species are present, little is known about interspecific social learning. Domesticated and urbanized species provide the opportunity to investigate whether nonhuman animals can learn from heterospecifics such as humans, who are integral parts of their social landscape. Although domestic dogs Canis familiaris have been intensively researched for their ability to learn from humans, most studies have focused on dogs living as pets. However, free-ranging dogs represent the majority of the world's dog population, they live alongside humans, scavenge on human refuse, and are subject to natural and sexual selection. Thus, free-ranging dogs with extensive exposure to humans and their artifacts provide the opportunity to investigate interspecific social learning in a naturalistic setting, where learning from humans might be a benefit for them. Here we tested individual free-ranging dogs in a between-subject design: Dogs in the control group could spontaneously choose between two novel and differently patterned food-delivering boxes. In the experimental group, instead, dogs could first observe an unfamiliar human approaching and eating from 1 of the 2 boxes. We provide the first evidence that free-ranging dogs match the choice of an unfamiliar human. These results show that at least simple forms of interspecific social learning might be involved in dogs' success in living alongside humans in a complex urbanized environment.

Scavengers in the human-dominated landscape: an experimental study.

Rapid urbanization is a major cause of habitat and biodiversity loss and human-animal conflict. While urbanization is inevitable, we need to develop a good understanding of the urban ecosystem and the urban-adapted species, in order to ensure sustainable cities for our future. Scavengers play a major role in urban ecosystems, and often, urban adaptation involves a shift towards scavenging behaviour in wild animals. We experimented at different sites in the state of West Bengal, India, to identify the scavenging guild within urban habitats, in response to human-provided food. Our study found a total of 17 different vertebrate species across 15 sites, over 498 sessions of observations. We carried out network analysis to understand the dynamics of the system and found that the free-ranging dog and common myna were key species within the scavenging networks. This study revealed the complexity of scavenging networks within human-dominated habitats. This article is part of the theme issue 'Connected interactions: enriching food web research by spatial and social interactions'.

Tick paralysis induced by Ixodes gibbosus: enigmatic cases in domestic mammals from Cyprus.

Tick paralysis is a potentially fatal condition caused by toxins produced and secreted by tick salivary glands. This survey presents clinical and epidemiological observations of tick paralysis cases in domestic animals in Cyprus. Local veterinarians report typical tick paralysis cases occurring in goats, sheep, dogs, and cats. The animals suffering from paralysis are free from other neurological diseases, have blood and biochemical parameters within normal ranges, and recover fast by simply removing the ticks found predominantly on the head and around the neck. Tick paralysis cases occur in a specific geographic area of Cyprus (Akamas peninsula), from September through March, but not every year. Instead, the phenomenon has 2 periodic cycles of occurrence, a 3- and a 7-year cycle. The 2 cycles are differentiated by severity based on the number of affected animals and the resulting losses. As described for other tick-borne diseases, these cyclic patterns may be attributed to external factors, self-oscillations of the disease system, or the combined action of these mechanisms. Ticks collected from a recent paralysis case in a goat were morphologically and molecularly identified as Ixodes gibbosus. Efforts should be made to characterize the specific toxins involved in tick paralysis and to develop a vaccine, which could prevent significant losses of small ruminants, especially in free-ranging farming systems, a prevalent management approach observed in Cyprus and various regions worldwide.

Gut microbiome is associated with personality traits of free-ranging Tibetan macaques (Macaca thibetana).

Recent studies have emphasized that there is a strong link between the gut microbiome and the brain that affects social behavior and personality in animals. However, the interface between personality and the gut microbiome in wild primates remains poorly understood. Here, we used high-throughput sequencing and ethological methods in primate behavioral ecology to investigate the relationship between gut microbiome and personality in Tibetan macaques (Macaca thibetana). The behavioral assessment results indicated three personality dimensions including socialization, shyness, and anxiety. There was significant variation in alpha diversity only for shyness, with a significantly lower alpha diversity indices (including Shannon, Chao1, and PD) for bold individuals than for shy individuals. Using regression models to control for possible confounding factors, we found that the relative abundance of three genera, Akkermansia, Dialister, and Asteroleplasma, was significantly and positively correlated with the sociability scores in the macaques. In addition, Oscillospiraceae exhibited a positive correlation with scores for Shy Dimension. Furthermore, we found that the predicted functional genes for propionate and pyruvate, porphyrin and chlorophyll metabolic pathways related to animal behavior, were significant enriched in shyness group. We propose that the gut microbiome may play an important role in the formation of personality of Tibetan macaques.

Health Effects of Patagial Wing Tags in Red Kites (Milvus milvus) in the UK.

Patagial wing tags are commonly used for identification of Red Kites (Milvus milvus) for postrelease monitoring, as they are easy to apply, affordable, permanent, and are apparently safe. The Red Kite was successfully reintroduced in the UK in the second half of the 20th century and postrelease health surveillance has been achieved through radio and satellite tracking, monitoring nest sites, and pathologic investigation of Red Kites found dead. This study reports on pathologic findings associated with the use of patagial wing tags in three of 142 (2.1%) wing-tagged Red Kites examined postmortem since the beginning of the reintroduction project in 1989. In these three Red Kites the presence of the patagial wing tags was associated with inflammatory lesions. Further surveys of the potential short- and longer-term negative effects of patagial wing tags on Red Kites and other birds are advocated; the future use of patagial wing tags in raptors should be carefully monitored.

Home range size and habitat selection of owned outdoor domestic cats (Felis catus) in urban southwestern Ontario.

Domestic cats (Felis catus) play a dual role in society as both companion animals and predators. When provided with unsupervised outdoor access, cats can negatively impact native wildlife and create public health and animal welfare challenges. The effective implementation of management strategies, such as buffer zones or curfews, requires an understanding of home range size, the factors that influence their movement, and the types of habitats they use. Here, we used a community/citizen scientist approach to collect movement and habitat use data using GPS collars on owned outdoor cats in the Kitchener-Waterloo-Cambridge-Guelph region, southwestern Ontario, Canada. Mean (± SD) 100% minimum convex polygon home range size was 8 ± 8 ha (range: 0.34-38 ha) and was positively associated with road density but not with intrinsic factors such as boldness, sex, or age. With regards to habitat selection, cats used greenspaces, roads, and agricultural land less often than predicted but strongly selected for impervious surfaces (urban areas other than greenspaces or roads). Our results suggest that wildlife near buildings and residential areas are likely at the greatest risk of cat predation and that a buffer size of 840 m would be needed to restrict cats from entering areas of conservation concern.

Heart rate reduction during voluntary deep diving in free-ranging loggerhead sea turtles.

Air-breathing vertebrates exhibit cardiovascular responses to diving including heart rate reduction (diving bradycardia). Field studies on aquatic mammals and birds have shown that the intensity of bradycardia can vary depending on diving behaviour, such as the depth of dives and dive duration. However, in aquatic reptiles, the variation in heart rate during deep dives under natural conditions has not been fully investigated. In this study, we released five loggerhead sea turtles (Caretta caretta) outfitted with recorders into the sea and recorded their electrocardiogram, depth, water temperature and longitudinal acceleration. After 3 days, the recorders automatically detached from the turtles. The heart rate signals were detected from the electrodes placed on the surface of the plastron. The mean (±s.d.) heart rate of 12.8±4.1 beats min-1 during dives was significantly lower than that of 20.9±4.1 beats min-1 during surface periods. Heart rate during dives varied with dive depth, although it remained lower than that at the surface. When the turtle dived deeper than 140 m, despite the relatively high flipper stroke rate (approximately 19 strokes min-1), the heart rate dropped rapidly to approximately 2 beats min-1 temporarily. The minimum instantaneous heart rate during dives was lower at deeper dive depths. Our results indicate that loggerhead sea turtles show variations in the intensity of diving bradycardia depending on their diving behaviour, similar to that shown by marine mammals and birds.

An In-Depth Look at Fonni's Dog Behavior under Different Outdoor Conditions.

This study aimed to investigate the common social and communicative behaviors of the Fonni's Dog under different outdoor conditions. For this study, 70 adult dogs (3-7 years; 32 intact males, 38 intact females) belonging to the Fonni's breed were used. A total of 35 dogs were kept in kennels and 35 were free-ranging dogs in their sheep/goat livestock units. A behavioral repertoire was adapted from the literature and an ethogram was filled in for each dog. All dogs were evaluated in the presence of the owner. Fisher's exact test, following Bonferroni's correction, was used to test possible differences in the categorical variables (presence or absence of the behavior) between free-ranging dogs and dogs kept in kennels. The study revealed that several categories of the dogs' body language were associated with the management condition. However, the breed motivations (guarding and defense of the territory) were satisfied both in kennel and in the animals who were free in the property. The current study suggests a good behavioral balance of the Fonni's Dogs which could be attributed to correct communication between dogs and owners.

Reduce, Replace, Refine: Determining A Posteriori Reference Intervals for Biochemistry in Hermann's Tortoise (Testudo hermanni).

Biochemical and hematological analyses are important for the assessment of animal health. However, for most wild species their use is hindered by the scarcity of reliable reference intervals. Indeed, collecting body fluids (e.g., blood, urine) in free-ranging animals is often technically challenging. Further, sampling many individuals would be essential to consider major sources of variations, such as species, populations, sex, age, and seasons. One alternative, according to the reduction, refinement, and replacement framework, is to establish reference intervals a posteriori using literature survey and unpublished data. We produced reference intervals for free-ranging Hermann's tortoises (Testudo hermanni), using analyses performed on blood samples collected in previous studies and conservation programs conducted in the field between 2010 and 2016 in southern France (n=195 individuals). Thirteen parameters were analyzed: packed-cell volume, blood concentrations of corticosterone, testosterone, glycemia, cholesterol, triglyceride, urea, uric acid, calcium, sodium, potassium, asparagine aminotransferase (AST), and alanine aminotransferases (ALT). Reference intervals for subgroups defined by sex and season were relevant for corticosterone, triglyceride, and calcium (sex) and cholesterol (season). Comparing our results with those obtained in captive individuals in Germany, except for urea and AST levels the intervals from both free-ranging versus captive tortoises were similar, suggesting that reference intervals established from captive individuals may be suitable for free-ranging populations in this species.

Detection of circovirus in free-ranging brown rats (Rattus norvegicus).

Accidentally found, two poisoned brown rats from Hungary were surveyed for presence of circoviral DNA, using specific nested primers, designed against the rep gene of the virus. Both specimens were positive. The whole genomes were amplified using inverse PCR based on the Rep sequence parts and sequenced by the primer walking method. Genomic analyses revealed that these novel rat viruses, together with tawny owl-associated circovirus reported by Italian researchers in 2022, are sequence variations of the same virus from genus Circovirus. In phylogenetic reconstructions, these circovirus strains detected from brown rats clustered closest to circoviruses derived from faeces samples of various predatory mammals. Molecular data as well as the phylogenetic analyses of the complete derived replication-associated protein and the capsid protein, as well as the prey preference of the host species of the recently described tawny owl-associated virus suggest that brown rat could be the evolutionary adapted host of the viruses described in this paper (brown rat circovirus types 1 and 2) and the previously reported tawny owl-associated virus. Possible pathogenic and zoonotic role of these viruses need further studies.

Evidence-based legislation, strong institutions and consensus needed to mitigate the negative impacts of free-ranging dogs.

Dogs bring many benefits to our society but, if not properly managed, they can be detrimental for humans, livestock and wildlife. We highlight the increasing problems associated with free-ranging dogs using examples from two regions of the world where this issue is pervasive, India and South America. In these regions, free-ranging dogs spread diseases, injure people, harm biodiversity, and negatively impact human livelihoods. We discuss why mitigating these deleterious effects can be extremely complicated because there are diverse challenges such as: (a) a lack of or inappropriate legislations concerning free-ranging dog management and human-dog interactions, (b) unregulated intentional and unintentional feeding of free-ranging dogs, (c) limitations of animal shelters, (d) non-responsible ownership, and (e) uncontrolled dog populations. As the management of animal species is usually shaped by differing interests, existing policies and regulations, views and social influence of stakeholders, power asymmetries between interested parties is yet another challenge in this regard. We need evidence-based legislations and strong institutions (e.g., public health and conservation institutions) that are capable of implementing governance principles and managing the complexities of this socio-ecological system by taking science-based decisions, and balancing power asymmetries to promote consensus.

Factors Predicting Apparent Ophidiomycosis in Wild Brown Watersnakes (Nerodia taxispilota).

Ophidiomycosis, also known as snake fungal disease, is caused by Ophidiomyces ophidiicola and is a threat to snake conservation worldwide. Ophidiomycosis has been reported throughout much of the eastern US, and outbreaks have been associated with local population declines of already strained populations. Previous studies report significant variability in ophidiomycosis among species sampled, with higher prevalence typically observed in Nerodia spp. Although ophidiomycosis can lead to morbidity and mortality in affected individuals, little is known about disease dynamics in free-ranging populations. Herein, we examine how individual-specific factors (e.g., life stage [immature, mature], contaminant status, sex, hemograms) may be associated with ophidiomycosis status in the brown watersnake (Nerodia taxispilota). During 2018-19, we sampled 97 N. taxispilota from five locations along the Savannah River in South Carolina and Georgia, US. Ophidiomyces ophidiicola DNA was detected in 66 snakes for a prevalence of 68% (95% confidence interval, 59-77). Mature snakes had a significantly higher risk of apparent ophidiomycosis (skin lesions present and quantitative PCR [qPCR], positive) relative to immature snakes. Snakes classified as having possible (skin lesions present, but qPCR negative) or apparent ophidiomycosis exhibited a relative azurophilia and heterophilia compared with individuals classified as negative (P≤0.037). Nerodia taxispilota in this region appear to have a high prevalence of apparent ophidiomycosis (22%; 95% CI, 14-31), similar to previous reports from the southeastern US. Additional epidemiologic investigations are warranted to further elucidate other individual-specific and environmental factors that may dictate disease risk and outcomes in affected populations.

Current practice for the chemical immobilisation of non-domestic feline species: An online survey study.

BACKGROUND: Safe chemical immobilisation of wild felids is essential for both conservational management and clinical purposes. However, little is known about drug protocols and current practice. METHODS: This study was designed as an online survey based on a questionnaire. Descriptive/correlation statistics and analysis of proportions were used for data analysis. RESULTS: The preferred immobilisation technique was the use of darts (37% of the respondents), while the most popular drug combination was a mixture of benzodiazepines, alpha-2 adrenoreceptor agonists and dissociative anaesthetics (27%). The inclusion of ketamine in the drug mixture was associated with a quicker anaesthetic onset, as estimated by the participants (p < 0.001). Common complications were prolonged recovery (46%), bradycardia (35%), hypoventilation (32%), hypothermia (26%) and arousal (26%). Commonly encountered problems were inappropriate equipment (39%), lack of suitable drugs (27%) and inadequate knowledge of species-specific pharmacology (29%) and physiology (24%). LIMITATIONS: Incomplete adherence to the Checklist for Reporting Results of Internet E-Surveys is acknowledged. CONCLUSIONS: Drug protocols including both alpha-2 adrenoreceptor agonists and dissociative anaesthetics are preferred in wild felids, and the inclusion of ketamine may be useful to achieve a quick onset. Equipment/drug availability and species-specific knowledge are potential areas of improvement to improve wild felid anaesthesia.

Salivary corticosterone reflects plasmatic levels in a wild seabird.

Wild animals have been increasingly exposed to a wide range of stressors, mainly due to the intensification of human activities and habitat modifications. Consequently, new tools in order to assess the physiological and health status of wild animals have been developed. In particular, glucocorticoids have received a special attention. Primarily metabolic hormones, they are also used to evaluate the stress level of organisms. While historically measured in blood samples, new less-invasive methods have been recently developed to measure glucocorticoids in matrices such as faeces, hairs/feathers, or saliva. To date, measurements in saliva are still in their infancy despite the numerous advantages of the matrix: non-invasive, reflects the biologically active portion of glucocorticoids, allows to measure both baseline and stress-induced levels. In addition, most studies using saliva have been performed on domestic and captive animals, and recent development in wild animals have focused on mammals. Here, we show, for the first time, that saliva could also be reliably used in free-ranging birds, as glucocorticoid levels in saliva strongly correlated with plasma levels. This promising result opens new avenues for a non-invasive sampling method to assess health status of wild birds in conservation biology and ecology.

Metagenomic and Molecular Detection of Novel Fecal Viruses in Free-Ranging Agile Wallabies.

The agile wallaby (Notamacropus agilis) is one of the most abundant marsupial species in northern Queensland and a competent host for the zoonotic Ross River virus. Despite their increased proximity and interactions with humans, little is known about the viruses carried by these animals, and whether any are of conservation or zoonotic importance. Metagenomics and molecular techniques were used in a complementary manner to identify and characterize novel viruses in the fecal samples of free-ranging agile wallabies. We detected a variety of novel marsupial-related viral species including agile wallaby atadenovirus 1, agile wallaby chaphamaparvovirus 1-2, agile wallaby polyomavirus 1-2, agile wallaby associated picobirnavirus 1-9, and a known macropod gammaherpesvirus 3. Phylogenetic analyses indicate that most of these novel viruses would have co-evolved with their hosts (agile wallabies). Additionally, non-marsupial viruses that infect bacteria (phages), plants, insects, and other eukaryotes were identified. This study highlighted the utility of non-invasive sampling as well as the integration of broad-based molecular assays (consensus PCR and next generation sequencing) for monitoring the emergence of potential pathogenic viruses in wildlife species. Furthermore, the novel marsupial viruses identified in this study will enrich the diversity of knowledge about marsupial viruses, and may be useful for developing diagnostics and vaccines.

First Detection of Cryptosporidium parvum in the Endemic Cyprus Mouflon (Ovis gmelini ophion).

PURPOSE: Cryptosporidium is an intestinal zoonotic protozoan parasite that infects domesticated and wild animals. There are no reports on the prevalence and molecular characterisation of Cryptosporidium in the endemic Cyprus mouflon. The mouflon is strictly protected by national and international legislation. Its main distribution is Paphos State Forest and surrounding areas, where it may share the same water sources as free-ranging domestic goats. Therefore, the present study aimed to determine the prevalence of Cryptosporidium spp. and genotypes in mouflon and free-ranging goats within the mouflon range. METHODS: Faecal samples of 70 mouflons and 34 free-ranging goats were screened for Cryptosporidium by PCR amplification and sequencing. RESULTS: Only one sample (1/70) belonging to a mouflon was PCR positive for Cryptosporidium. Based on sequencing of the 18S rRNA locus, this species was identified as Cryptosporidium parvum (C. parvum). No positive sample was detected in the free-ranging goats (0/34). CONCLUSION: This is the first report on the molecular identification of this Cryptosporidium species in a Cyprus mouflon. The results indicate that the prevalence of Cryptosporidium in Cyprus mouflon is low.

Serological and molecular detection of Toxoplasma gondii and Neospora caninum in free-ranging rats from Nagpur, India.

Toxoplasma gondii and Neospora caninum are cyst-forming coccidian parasites that infect both wild and domestic non-felids as intermediate hosts, with rodents serving as important reservoir hosts during their life cycles. This study was aimed at investigating T. gondii and N. caninum infections and identifying factors favouring T. gondii infection in free-ranging rats from India. A total of 181 rodents were trap-captured, and blood and brain samples were subsequently collected for serological and molecular examination of T. gondii and N. caninum. Antibodies against T. gondii and N. caninum were detected by MAT/NAT and IFAT in 13.8% (25/181) and 1.65% (3/181) of rodents, respectively. All three N. caninum samples positive by NAT/IFAT were also positive for ELISA, while for T. gondii, 19 of 25 MAT/IFAT positive samples were also positive for ELISA. The antibody titers (MAT/NAT/IFAT) of rodents seropositive for T. gondii ranged from 25 to 400, while those of rats seropositive for N. caninum ranged from 25 to 100. Also, using PCR, DNA from T. gondii (B1 gene) and N. caninum (NC5 gene) was found in 2.76% (5/181) of brain samples and 0.55% (1/181) of brain samples. All PCR positive samples were also seropositive. No mixed infections were observed in the serological and molecular detections. A Chi-square analysis revealed that older rats and rats living in urban areas are significantly associated with T. gondii infection; however, rodent species, gender, location, habitat types, and seasonality were statistically nonsignificant. Overall, this study demonstrated that T. gondii was widely distributed while N. caninum was less prevalent among free-ranging rats in the studied area.

Serum biochemical reference interval determination in wild Siberian weasel (Mustela sibirica).

Determining reference intervals (RI) is a valuable asset for assessing the health of wildlife species. This is the first study to establish serum biochemical RIs in Siberian weasels. Forty-two healthy free-ranging Siberian weasels were captured live and brought to Seoul Wildlife Center between June 2021 and August 2022. Blood samples from 42 healthy Siberian weasels of both sexes were used to calculate RIs. An automated analyser was used to perform serum biochemistry profiles. The American Society for Veterinary Clinical Pathology recommendations were used to calculate a nonparametric RI with 90% confidence intervals. The RIs of albumin, total protein, globulin, calcium, glucose, blood urea nitrogen, phosphorus, amylase, cholesterol, alanine aminotransferase, total bilirubin, alkaline phosphatase, creatinine, and creatine kinase were determined. The RIs established in this study will serve as a good starting point for analysing serum biochemical data in Siberian weasels.

The Role of Some Free-Ranging Animals in the Transmission of Multi-Host Species of Cryptosporidium Spp.

Background: We aimed to characterize Cryptosporidium spp. in rats, cats, pigeons, and crows. Methods: Fifty-five animal origin Cryptosporidium spp. genome were identified, genotyped and confirmed by nested PCR and of RFLP-PCR analysis as well as sequenced based on 18s rRNA and gp60 genes in Tehran (2012-2019). Finally, the phylogenetic analysis was performed by MEGA software (version 7). Results: By the molecular method, Cryptosporidium spp. were detected in 24 (15.2%), 15 (15%), 2 (2%) and 13 (13%) cases of wild rats, cat, pigeon, and crow, respectively. Among the identified species by the RFLP pattern, most isolates were identified as C. parvum (24/157) 17.8% in rats, (15/100) 15% in cats, (13/100) 13%in crew and (2/100) 2% in pigeons; and the rest of the cases were C. muris and C. felis. The results of sequencing did not prove the existence of C. parvum, C. felis, C. muris, and rat genotype. Subtyping of C. parvum was indicated that the dominant subtype family belongs to the IId family and the subtype A20G1 was the most common subtype detected in all hosts while A19G1 was detected in one isolate of cat and pigeon. Conclusion: Free-ranging animals are infected by species/subtype of Cryptosporidium, which can infect humans. This shows by itself the hygienic importance of the free-ranging animals in urban ecosystems. In the transmission of human cryptosporidiosis, the multi-host Cryptosporidium species such as C. parvum, C. felis, and C. muris can be transferred potentially from these animals to humans.

The illegal rearing and slaughtering of pigs in the wild on the Mediterranean island of Sardinia favor an increase in the biomass of Trichinella britovi in wild boars (Sus scrofa) but do not affect the serological prevalence of infection.

BACKGROUND: Worms of the nematode genus Trichinella are zoonotic pathogens with a worldwide distribution. The first report of Trichinella on the Mediterranean island of Sardinia was for Trichinella britovi, one of the four species of this genus circulating in Europe, which was identified in 2005 following an outbreak of trichinellosis in humans due to the consumption of pork from pigs reared in the wild. Since then, T. britovi larvae have been repeatedly isolated from free-ranging pigs, foxes (Vulpes vulpes) and wild boars (Sus scrofa) sampled in the central-eastern region of the island (Orgosolo municipality), but have never been isolated from samples from other areas of the island. The aim of this study was to investigate the parasitological and serological prevalence of T. britovi infection in wild boars in Sardinia over space [eight wild boar hunting management units (HMUs)] and time (seven wild boar hunting seasons). METHODS: Muscle and serum samples of boars killed in the 2014-2015 to 2020-2121 hunting seasons were collected from eight HMUs of central and south-western Sardinia. Trichinella sp. larvae were detected by artificial digestion of predilection muscles. A total of 4111 serum samples of wild boar were collected from the investigated HMUs and tested by enzyme-linked immunosorbent assay as a screening test and by western blot as a confirmatory test using excretory/secretory antigens. RESULTS: Trichinella britovi muscle larvae were detected in six (0.03%) of the 17,786 wild boars tested. All of the Trichinella sp.-positive wild boars had been hunted in Orgosolo municipality (central-eastern area of the island), except for one, hunted in a neighboring municipality. An overall serological prevalence of 3.8% (95% confidence interval, 3.3-4.5) was detected by western blot. No statistical differences were detected between the HMUs where T. britovi larvae were detected in wild boars, foxes, and free-ranging pigs and those where wild boars, foxes and free-ranging pigs tested negative. CONCLUSIONS: The serological prevalence did not vary between the wild boar populations in which the larval load was detectable by artificial digestion (Orgosolo municipality) and those in which the larval load was below the detection limit. Furthermore, the serological prevalence of anti-Trichinella immunoglobulin G in the wild boar populations remained constant during the study period, which covered seven wild boar hunting seasons. As the transmission events (i.e., the serological prevalence) are stable, the high biomass of the parasite in Orgosolo municipality can only have arisen as a consequence of factors independent of its natural cycle, i.e., the presence of a high number of free-ranging pigs, and the concomitant presence of African swine fever, due to illegal pig slaughtering in the field. This epidemiological situation suggests that the natural cycle of T. britovi may be influenced by inappropriate pig husbandry and slaughtering practices.