Mucormycosis is a well-recognized fungal disease affecting Tasmanian platypuses (Ornithorhynchus anatinus). The causative agent, Mucor amphibiorum, has been found to infect both native and introduced amphibians of the Au...Mucormycosis is a well-recognized fungal disease affecting Tasmanian platypuses (Ornithorhynchus anatinus). The causative agent, Mucor amphibiorum, has been found to infect both native and introduced amphibians of the Australian mainland; however, there are no previous reports of this infection in platypuses of the Australian mainland.
A retrospective case study evaluated the effectiveness of butorphanol (27.3 mg/mL), azaperone (9.1 mg/mL), and medetomidine (10.9 mg/mL; BAM) in captive pronghorn (Antilocapra americana) during 2021-24. Immobilizations w...A retrospective case study evaluated the effectiveness of butorphanol (27.3 mg/mL), azaperone (9.1 mg/mL), and medetomidine (10.9 mg/mL; BAM) in captive pronghorn (Antilocapra americana) during 2021-24. Immobilizations were inconsistent, with documented cases of spontaneous arousal (e.g., head movement, walking, running). Use of BAM in pronghorn should be considered with caution.
This study aimed to detect and characterize intracellular blood parasites of the phylum Apicomplexa in freshwater turtles. Microscopic analysis identified developmental stages of gamonts and premeronts belonging to the g...This study aimed to detect and characterize intracellular blood parasites of the phylum Apicomplexa in freshwater turtles. Microscopic analysis identified developmental stages of gamonts and premeronts belonging to the genus Haemogregarina, while molecular analyses confirmed the presence of Haemogregarina stepanowi, Haemogregarina spp., and Hepatozoon sp. The mean parasitemia was 29.7 parasites per 10,000 erythrocytes. Hematologic examinations showed elevated basophil and eosinophil counts in infected individuals, indicating an immune response to the infection. Phylogenetic analyses supported the close genetic relationship of isolates from this study with hemoparasites found in other freshwater turtle species. Overall, these results contribute to the understanding of the diversity and genetic relationships of hemogregarine species in freshwater turtles.
Alopecic syndrome in Guadalupe fur seals, Arctocephalus philippii townsendii (GFSs), was first observed a decade ago, coinciding with an anomalous warm sea surface temperature event and shifts in foraging behaviors of ot...Alopecic syndrome in Guadalupe fur seals, Arctocephalus philippii townsendii (GFSs), was first observed a decade ago, coinciding with an anomalous warm sea surface temperature event and shifts in foraging behaviors of otariid pinnipeds from Mexican North Pacific colonies. With no evidence of dermatophytes or ectoparasites commonly associated with alopecia, it has been proposed that nutritional or metabolic changes, secondary to altered foraging, may increase the risk of alopecia. We employed 16S rRNA gene deep sequencing to investigate changes in the fecal bacteriome of GFS with and without alopecia. We found no significant differences in species richness nor Simpson's diversity index, and alopecia accounted for less than 6% of the variation in bacteriome structure. However, five bacterial phyla (Bacteroidota, Firmicutes, Fusobacteriota, Proteobacteria, and Spirochaetota) were overrepresented, and two (Actinobacteriota and Campylobacterota) were underrepresented, in GFSs with alopecia. At the genus level, animals with alopecia had a higher abundance of various bacteria, including Parabacteroides, Bacteroides, Lachnospiraceae, Roseburia, and genera within Erysipelotrichaceae, which have been linked to alopecia in humans. The GFS fecal bacteriome revealed 322 distinct bacterial functional pathways, of which 163 varied significantly between cases and controls. The most prominent differences found in GFSs with alopecia were overrepresentation of critical precursors for bacterial cell wall components, aromatic amino acid biosynthesis and pantothenate and CoA biosynthesis, and underrepresentation of glucosyltransferases and bacterial surface antigens, nitrogen and sulfur metabolism, and bacterial secretion systems. Our study provides preliminary evidence that changes in enteric microbiota may contribute to the pathogenesis of alopecia in GFSs via three main mechanisms: dysregulation of immune modulation and sustained inflammation, altered metabolism, and reduced redox balance and detoxification in the gut. While future studies need to explore these possibilities, our findings offer insight into the role of the microbiome in emerging pathologies of wildlife.
Toxoplasma gondii is a globally distributed parasite that infects a wide range of warm-blooded animals and requires felids as definitive hosts. Although birds are recognized carriers of T. gondii, in New Zealand species...Toxoplasma gondii is a globally distributed parasite that infects a wide range of warm-blooded animals and requires felids as definitive hosts. Although birds are recognized carriers of T. gondii, in New Zealand species morbidity and mortality events have been sporadically reported, and systematic data are lacking. The objective of this study was to determine the prevalence and tissue distribution of T. gondii in three common aquatic birds in New Zealand: the native Red-billed Gull (Chroicocephalus scopulinus) and Black-backed Gull (Larus dominicanus), and the introduced Mallard (Anas platyrhynchos). Birds were collected between September 2022 and April 2025 and screened using nested PCR with two commonly used primer sets (B1, targeting the B1 gene, and FOOD, targeting the pppk-dhps region). Five organs (liver, lung, heart, brain, and spleen) were tested to compare detection rates across tissues. Overall, prevalence was low but consistent across primers and tissues in all three species. Black-backed Gulls and Mallards showed higher prevalence than Red-billed Gulls, probably reflecting differences in diet, habitat, and behavior. Brain and heart tissues yielded the highest detection rates, and the FOOD primers were approximately twice as sensitive as the B1 set. These findings provide practical guidance for primer and tissue selection in avian T. gondii studies and represent the first assessment of infection in these three bird species in New Zealand. They also highlight potential ecologic differences among species that may influence exposure to T. gondii.
The release of rehabilitated wildlife can introduce antimicrobial resistance (AMR) into wild ecosystems. We examined AMR in Escherichia coli isolated from 44 Bolivian red howler monkeys (Alouatta sara) at a rescue center...The release of rehabilitated wildlife can introduce antimicrobial resistance (AMR) into wild ecosystems. We examined AMR in Escherichia coli isolated from 44 Bolivian red howler monkeys (Alouatta sara) at a rescue center in Madre de Dios, Peru. Fecal samples were collected noninvasively and processed for E. coli isolation. Antimicrobial susceptibility testing against 12 antibiotics was performed and extended-spectrum beta-lactamase (ESBL) production was phenotypically confirmed. Multidrug resistance (MDR) and the multiple antibiotic resistance (MAR) index were calculated. We isolated E. coli from 43/44 sampled monkeys (98%). Only 1/85 (1%) E. coli isolates was an ESBL producer, and this isolate exhibited MDR to eight antibiotics across five classes. Non-ESBL isolates (n=84) showed the highest resistance to tetracycline (13%), sulfamethoxazole-trimethoprim (10%), and chloramphenicol (5%). Five isolates (6%) were MDR, and seven (8%) had a MAR index ≥0.2. Although ESBL prevalence was low, the presence of MDR and critical AMR profiles emphasizes the importance of surveillance, following the One Health approach, in primate rehabilitation programs to help prevent potential AMR spread during wildlife release.
Toxoplasma gondii-the causative agent of toxoplasmosis-is a zoonotic pathogen of warm-blooded hosts. Infection causes mild-to-severe symptoms, including lethargy, fever, muscle pain, abortion, ocular disease, and encepha...Toxoplasma gondii-the causative agent of toxoplasmosis-is a zoonotic pathogen of warm-blooded hosts. Infection causes mild-to-severe symptoms, including lethargy, fever, muscle pain, abortion, ocular disease, and encephalitis. Toxoplasma affects many vertebrate species, although felids are the only known definitive hosts. Seroprevalence in wildlife is often assessed using cross-sectional data, but few studies have tracked individual-level infections through time. We present a 4-yr dataset from white-tailed deer (Odocoileus virginianus) with repeated sampling of individuals that highlights challenges associated with assigning serostatus to individuals. Using a modified agglutination test, we observed seroconversion from seronegative to seropositive within individuals, as expected. Although toxoplasmosis is known to be a chronic disease, we also found reversion from seropositive to seronegative. Accurate assignment of serostatus is necessary for evaluating effects of infection on behavioral and physiologic outcomes. However, longitudinal data from individuals whose titers oscillate around the positive threshold present novel challenges. Therefore, we discuss the implications for assigning serostatus for chronic toxoplasmosis infection for three proposed approaches: 1) ever positive, always positive; 2) negative until positive and then always positive; and 3) status by sampling period. Clarifying which approach is used to assign serostatus when analyzing longitudinal T. gondii data may enable more meaningful comparisons across systems and studies.
Chronic wasting disease (CWD) is a fatal prion disease in cervids. Because prions persist in the environment, early detection is essential for containment. Trained detection dogs have shown promise as a noninvasive surve...Chronic wasting disease (CWD) is a fatal prion disease in cervids. Because prions persist in the environment, early detection is essential for containment. Trained detection dogs have shown promise as a noninvasive surveillance method through identification of volatile organic compounds associated with CWD in white-tailed deer (WTD; Odocoileus virginianus) fecal matter. To reduce the risk of environmental contamination, recent CWD detection work has used cotton training aids incubated (i.e., passively odor exposed without direct contact) with small quantities of WTD fecal matter. However, operational detection scenarios often involve exposure to much larger volumes of fecal matter, requiring detection dogs to generalize from their training aid odor to the real-world target odor. This study examined whether detection dogs trained on cotton aids incubated for 24 h with 1-2 g of fecal matter (small quantity) could generalize to aids incubated for 24 h with 22 g of fecal matter (large quantity). Four detection dogs completed two tests: the first test measured their initial responses to the large-quantity aids and the second test was conducted after three training sessions in which they were positively reinforced for alerting to the large-quantity aids. Dogs did not significantly differentiate between CWD-positive and CWD-negative samples in the first large-quantity test, but showed significant improvement after training; as such, generalization did not occur spontaneously from training only on small-quantity aids, but a brief training exposure to the larger-quantity aids enabled better performance. This study emphasizes the importance of considering odor variability between training scenarios and the operational scenario. Results provide information relevant to improving operational field performance. Future work should explore training paradigms that increase flexibility in odor recognition across different contexts.
The giant otter (Pteronura brasiliensis) is the largest river otter in the world and globally classified as endangered. Little information is available regarding pathogen exposure in this species due to low densities and...The giant otter (Pteronura brasiliensis) is the largest river otter in the world and globally classified as endangered. Little information is available regarding pathogen exposure in this species due to low densities and the challenges associated with capturing individuals in the wild. Serological assays were used to investigate exposure of 10 free-ranging giant otters from different Brazilian ecoregions to canine distemper virus (CDV), parvovirus, rabies virus, Leptospira spp., smooth Brucella, and Toxoplasma gondii. Molecular assays were conducted to assess the presence of Hepatozoon spp., Cytauxzoon spp., and Babesia spp. Serum antibodies were detected for CDV (5/10), canine parvovirus (2/10), rabies virus (1/7), Leptospira spp. (2/10), and T. gondii (3/10). None of the giant otters were exposed to smooth Brucella. Of the individuals that received molecular testing, 2/6 were positive for Hepatozoon spp., and 0/6 were positive for Babesia spp. or Cytauxzoon spp. These results provide the first data on pathogen exposure in free-ranging giant otters. Long-term monitoring of these populations is essential to determine which pathogens are endemic and which may pose a conservation threat to giant otters.
Plague is a zoonotic disease of mammals caused by the bacterium Yersinia pestis. Because plague is primarily transmitted by fleas (Siphonaptera), rates of plague transmission are expected to increase with flea abundance....Plague is a zoonotic disease of mammals caused by the bacterium Yersinia pestis. Because plague is primarily transmitted by fleas (Siphonaptera), rates of plague transmission are expected to increase with flea abundance. Edaphic factors can influence the abundance and dispersion of fleas, suggesting that soils may play important roles in plague ecology. From June to August 2010-12, in northern New Mexico, USA, we investigated the effects of soil texture, soil moisture, and soil water-holding capacity on the abundance of adult fleas parasitizing colonial, burrowing black-tailed prairie dogs (Cynomys ludovicianus, BTPDs). We sampled BTPDs 1,741 times on 20 sampling plots distributed among 13 BTPD colonies, detecting 9,541 adult fleas on BTPDs. Fleas were most abundant on BTPDs in areas with coarse surface soils, and in areas with moderately textured subsurface soils at the average depth of BTPD nest chambers. Coarse surface soils may facilitate water percolation to BTPD nests, where the moisture could generate humid microclimates that benefit desiccation-prone fleas. Moderately textured subsurface soils, of intermediate water-holding capacity, can store water, which may increase burrow humidity. Moreover, moderately textured subsurface soils in BTPD nests may increase survival of flea larvae and pupae, facilitating their development to adulthood. That said, excessive moisture and sodden soils can favor fungi and mites, some of which are lethal to fleas. In our study, fleas were most abundant in areas with subsurface soils of intermediate moisture content. Our findings complement an accumulating number of studies, indicating that edaphic factors play important roles in flea and plague ecology.
Wild Turkeys (Meleagris gallopavo ssp.) are a popular game bird in North America. Populations in many states in the USA have been declining due to unknown causes. Concern about potential impacts of disease on Wild Turkey...Wild Turkeys (Meleagris gallopavo ssp.) are a popular game bird in North America. Populations in many states in the USA have been declining due to unknown causes. Concern about potential impacts of disease on Wild Turkeys has been increasing. Lymphoproliferative disease virus (LPDV) is an avian retrovirus initially identified in domestic turkeys in Europe and Israel that often presented as lymphoid tumors and was associated with high mortality rates. In 2009 LPDV was first reported in the USA, and it has been reported in numerous USA states and Canadian provinces, though little is known about its effects on Wild Turkey populations. Our objective was to identify prevalence and spatial patterns of LPDV infection in Wild Turkeys in Iowa, USA. We tested bone marrow from 912 Wild Turkeys that were hunter-harvested (n=907), road-killed (n=3), or submitted for necropsy (n=2) for LPDV. Samples were collected between 2019 and 2021, but comprised primarily adult males from the 2020 spring harvest. We found that LPDV was distributed across Iowa, with an estimated statewide prevalence of 42.9%. Cluster analysis using Kulldorff's spatial scan statistic identified two clusters of higher prevalence (hotspots) and two clusters of lower prevalence (coldspots) than expected. The Iowa landscape is dominated by agriculture (81%) with a smaller amount of forest (7%). The two hotspots were located within some of the more heavily forested portions of the state (16.6% and 7.9% forest), while the coldspots had smaller amounts of forest (3.8% and 0.8%). Our results provide the first information on the prevalence and distribution of LPDV in Iowa and could be used to identify areas to prioritize continued surveillance as well as conduct research on the effects of LPDV on Wild Turkey populations.
Plague is a zoonotic disease of mammalian hosts and flea vectors. Wildlife biologists most commonly mitigate plague by controlling flea populations. We evaluated the efficacy of edible baits for systemic flea control wit...Plague is a zoonotic disease of mammalian hosts and flea vectors. Wildlife biologists most commonly mitigate plague by controlling flea populations. We evaluated the efficacy of edible baits for systemic flea control with two cricetid species on colonies of black-tailed prairie dogs (Cynomys ludovicianus): the western deer mouse (Peromyscus sonoriensis) and the northern grasshopper mouse (Onychomys leucogaster). We tested grain bait with 0.005% fipronil by weight and "FipBit" pellets with 0.46-1.52 mg of fipronil/pellet. Flea prevalence was assessed via combing of live-trapped mice. In one experiment with fipronil grain bait and FipBits (n=564 combings), flea prevalence declined from 74% (grain) and 45% (FipBits) before treatments to 0% for both treatments from 30-44 d and from 324-413 d after treatments. During a second experiment with FipBits (n=299 combings), flea prevalence declined from 13% to 32% before treatments to 0% from 11-15 d after treatments, but increased to 29-56% from 349-378 d after treatments. Results herein suggest annual fipronil bait treatments may be most effective for flea control.
Wildlife rabies is enzootic in the USA apart from Hawaii. This viral zoonosis perpetuates using mammalian reservoirs within the Chiroptera and Carnivora. In the southeastern USA, the predominant rabies virus variants are...Wildlife rabies is enzootic in the USA apart from Hawaii. This viral zoonosis perpetuates using mammalian reservoirs within the Chiroptera and Carnivora. In the southeastern USA, the predominant rabies virus variants are associated with raccoons (Procyon lotor) and bats. Besides being enzootic for bat rabies, Alabama is the westernmost USA state for raccoon rabies perpetuation. To assess the recent viral dynamics of wildlife rabies in Alabama, 65 samples of rabid animals were acquired from public health submissions during 2020-25. Rabies virus nucleoprotein gene sequences were generated for phylogenetic analysis. Two major viral lineages were identified: one lineage was aligned with raccoons and the other with bats. Host spillover infections of raccoon rabies virus were detected in domestic animals and other mesocarnivores. No bat rabies viruses were found in non-bat hosts, but several examples of interspecific transmission among bats were apparent. Such data are useful for tracking epidemiologic trends locally, to determine suspected host shifts, and for regional introspection related to management and potential translocation events.
Technical advancements have enabled the discovery of potential pathogens in an ever-broadening range of wildlife taxa. To further the scope of this body of knowledge and to inform conservation efforts, we examined potent...Technical advancements have enabled the discovery of potential pathogens in an ever-broadening range of wildlife taxa. To further the scope of this body of knowledge and to inform conservation efforts, we examined potential disease agents present in swamp rabbits (Sylvilagus aquaticus) of southeastern Missouri, USA, during winter 2023. This region represents the northernmost portion of the species' range and is characterized by an intermixed landscape of preferred bottomland hardwood forest and agricultural landcover. Concerns about infectious disease threats to swamp rabbits have increased since the emergence of rabbit hemorrhagic disease, caused by rabbit hemorrhagic disease virus 2 (RHDV2; Caliciviridae, Lagovirus europaeus), that has spread to domestic, wild, and feral rabbits and hares, predominantly in the western and midwestern USA. We applied metagenomic and metabarcoding methods, designed to characterize communities of viruses and parasites, to noninvasively collected rabbit fecal samples. We identified seven viruses and eight parasite genera that probably infect mammals. Although some relatives of these agents cause disease, none are unexpected in lagomorphs, and none are considered a health concern. Notably, RHDV2 was not detected. These results provide baseline data for future conservation and management efforts, especially if RHDV2 or other pathogens become a concern for swamp rabbits.
Numerous gammaherpesviruses can infect cervids, including those that cause malignant catarrhal fever, a lymphoproliferative disease of artiodactyls. Less is known about unclassified gammaherpesviruses in cervids, althoug...Numerous gammaherpesviruses can infect cervids, including those that cause malignant catarrhal fever, a lymphoproliferative disease of artiodactyls. Less is known about unclassified gammaherpesviruses in cervids, although they appear to be nonpathogenic in their adapted hosts. Adenoviruses can also cause disease in cervids, characterized outbreaks of localized or systemic vasculitis, especially in juveniles. We tested 31 samples from 24 white-tailed deer (Odocoileus virginianus) captured in Cook County, Illinois, USA for herpesviruses and adenoviruses via consensus PCR of combined nasal-rectal swabs. Over one-third (35%, 11/31) of samples, constituting 42% (10/24) of individual deer, were PCR-positive for a herpesvirus most similar to an unclassified gammaherpesvirus previously found in mule deer (Odocoileus hemionus) in Washington, USA and Saskatchewan, Canada. No deer tested positive for adenoviruses. All deer were apparently healthy on physical examination. Gammaherpesvirus detection is common in white-tailed deer in Cook County and does not appear to be associated with clinically apparent disease. However, the impact of this virus on white-tailed deer fitness or on non-adapted hosts is unknown.
This letter describes possible pathogen and antimicrobial resistance spillover from agricultural systems to wildlife through detection of zoonotic streptococci with resistance to a common veterinary antibiotic in a wild...This letter describes possible pathogen and antimicrobial resistance spillover from agricultural systems to wildlife through detection of zoonotic streptococci with resistance to a common veterinary antibiotic in a wild Tasmanian platypus (Ornithorhynchus anatinus). We propose platypus as a potential One Health sentinel species for surveillance in freshwater ecosystems.
Respiratory disease remains an important threat to bighorn sheep (BHS; Ovis canadensis), complicated by fragmented populations and environmental stressors. Significantly, BHS epizootic pneumonia can lead to all-age die-o...Respiratory disease remains an important threat to bighorn sheep (BHS; Ovis canadensis), complicated by fragmented populations and environmental stressors. Significantly, BHS epizootic pneumonia can lead to all-age die-offs and is population limiting. We describe an interagency investigation of a die-off within a BHS herd in the Badlands region of South Dakota, USA from 2021-22. Minimum survey counts began declining 2 mo following a reported domestic sheep (Ovis aries) and BHS interaction and dropped from 262 to 56 BHS over 9 mo. Postmortem testing included histopathology, bacterial culture, molecular testing, and partial microbial sequencing in 13 affected BHS. Data from neighboring domestic small ruminants and historical BHS data were compared to outbreak observations. Histopathology revealed moderate to severe bronchopneumonia in many cases. Half of animals examined harbored mild to heavy lungworm burdens (5/10). Pneumonic tissue culture yielded Trueperella pyogenes (10/11), Bibersteinia trehelosi (5/11), and no live Mycoplasma spp. (0/11). Conversely, real-time PCR detected widespread Mycoplasma ovipneumoniae (12/13) for the first time in this herd, with co-occurring bluetongue virus (BTV, 4/10). Two unique M. ovipneumoniae strains were found in BHS, one directly related to nearby domestic sheep isolates. Severe epizootic pneumonia was preceded by multi-strain M. ovipneumoniae spillover, with T. pyogenes causing suppurative pneumonia. High BHS density, a moderate-severe drought, and BTV transmission compounded disease susceptibility and mortality in this herd. Strengthened collaborations are necessary to manage BHS facing multiple coinciding health threats.
A South American raccoon (Procyon cancrivorus), native to Paraguay, was found to host eggs suggestive of Baylisascaris procyonis, a zoonotic nematode that can cause severe human disease. This first report from Paraguay h...A South American raccoon (Procyon cancrivorus), native to Paraguay, was found to host eggs suggestive of Baylisascaris procyonis, a zoonotic nematode that can cause severe human disease. This first report from Paraguay highlights the parasite's public health relevance and underscores the need for enhanced wildlife surveillance within a One Health framework.
Effective wildlife disease management and research rely on trustworthy disease diagnostics. For chronic wasting disease (CWD), immunohistochemistry (IHC) is recognized as the gold standard, and ELISA is a reliable high-t...Effective wildlife disease management and research rely on trustworthy disease diagnostics. For chronic wasting disease (CWD), immunohistochemistry (IHC) is recognized as the gold standard, and ELISA is a reliable high-throughput screening method validated for use on obex and retropharyngeal lymph node (RPLN) tissues. However, diagnostic performance of the assays when used on tissues from elk (Cervus canadensis) varies, particularly under varying CWD population prevalence. We used hierarchical Bayesian modeling to predict sensitivity and specificity of ELISA on obex and RPLN and IHC on obex, RPLN, and rectoanal mucosa-associated lymphoid tissue (RAMALT) from elk. We detected CWD prion in at least one tissue from 46/283 individuals tested postmortem between 2016 and 2020. Specificity of ELISA was nearly perfect, providing strong confidence in CWD-detected results. Predicted mean test sensitivity was greater for ELISA than for IHC and slightly greater for RPLN tissue than for obex. The most sensitive individual test was ELISA RPLN, whereas the most reliable CWD diagnosis was achieved by parallel testing of both the obex and RPLN by ELISA, with serial confirmation by IHC. Although RAMALT can be used for antemortem testing, its low sensitivity makes negative results unreliable for proving an animal is disease free. When positive and negative predictive values of these methods were evaluated, we found the reliability of diagnostic results varied widely within the observed range of disease prevalence, and poor reliability was exaggerated by low diagnostic performance. Test-negative results are more likely to be true early in disease invasion, whereas the risk of a false-negative result grows with increasing disease prevalence in the sampled population. Wildlife managers should consider both the objectives and the stage of disease invasion when interpreting diagnostic test results.
Multiple trematodes identified as Pegosomum bubulcum, a species that typically inhabits avian bile ducts, were found in ectopic locations, including the liver surface, coelomic cavity, and lungs of an Eastern Great Egret...Multiple trematodes identified as Pegosomum bubulcum, a species that typically inhabits avian bile ducts, were found in ectopic locations, including the liver surface, coelomic cavity, and lungs of an Eastern Great Egret (Ardea alba modesta), which also exhibited severe coelomitis, airsacculitis, and a markedly dilated, fibrotic extrahepatic bile duct.