Local and regional temporal trends (2013-2019) of canine Ehrlichia spp. seroprevalence in the USA

Surveillance of tick-borne pathogens present in ticks (Acari: Ixodidae) removed from companion animals in Louisiana, USA

Current knowledge of tick distribution and tick-borne pathogen presence across Louisiana is limited. Collaborating with veterinarians across the state, ticks removed from companion animals were recovered and assessed for the presence of zoonotic pathogens. A large number of ticks (n = 959) were removed from companion animals and subsequently screened using qPCR for Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Bartonella henselae, Ehrlichia chaffeensis, and spotted fever group Rickettsia. Five different tick species, Ixodes scapularis (54.5%), Amblyomma americanum (18.4%), Amblyomma maculatum (12.5%), Dermacentor variabilis (11.2%), and Rhipicephalus sanguineus (0.3%) from different regions of Louisiana were collected from October 2018 to July 2019. There were 15 PCR-positive ticks for Rickettsia parkeri (1.6% prevalence), and four ticks were positive for Ehrlichia chaffeensis (0.4% prevalence). This survey identifies ticks and tick-borne pathogens associated with companion animals and areas for future active surveillance.

Comparative speed of kill provided by lotilaner (Credelio™), sarolaner (Simparica Trio™), and afoxolaner (NexGard™) to control Amblyomma americanum infestations on dogs

BACKGROUND

Canine acaricides with rapid onset and sustained activity can reduce pathogen transmission risk and enhance pet owner experience. This randomized, complete block design, investigator-masked study compared the speed of kill of Amblyomma americanum provided by three monthly-use isoxazoline-containing products.

METHODS

Eight randomized beagles per group were treated (day 0), per label, with sarolaner (combined with moxidectin and pyrantel, Simparica Trio™), afoxolaner (NexGard™), or lotilaner (Credelio™), or remained untreated. Infestations with 50 adult A. americanum were conducted on days - 7, - 2, 21, and 28, and tick counts were performed on day - 5 (for blocking), and at 4, 8, 12, 24, 48, and 72 h following treatment and subsequent infestations. Efficacy calculations were based on geometric mean live tick counts. A linear mixed model was used for between-group comparisons.

RESULTS

On day 0, only lotilaner significantly reduced an A. americanum infestation by 12 h (43.3%; P = 0.002). Efficacy of lotilaner and afoxolaner at 24 h post-treatment was 95.3% and 97.6%, respectively, both significantly different from sarolaner (74%) (P = 0.002, P < 0.001, respectively). On day 21, at 12 h postinfestation, lotilaner efficacy (59.6%) was significantly different from sarolaner (0.0%) (P < 0.001) and afoxolaner (6.3%) (P < 0.001). At 24 h, lotilaner efficacy (97.4%) was significantly different (P < 0.001) from sarolaner and afoxolaner (13.6% and 14.9%, respectively). On day 28, at 12 h postinfestation, lotilaner efficacy (47.8%) was significantly different from sarolaner (17.1%) (P = 0.020) and afoxolaner (9.0%) (P = 0.006). At 24 h, lotilaner efficacy (92.3%) was significantly different from sarolaner 4.9% (P < 0.001) and afoxolaner (0.0%) (P < 0.001). Speed of kill for sarolaner and afoxolaner, but not lotilaner, significantly declined over the study period. Following reinfestation on day 28, neither sarolaner nor afoxolaner reached 90% efficacy by 48 h. By 72 h, sarolaner efficacy was 97.4% and afoxolaner efficacy was 86.3%. Only lotilaner achieved ≥ 90% efficacy by 24 h post-treatment and 24 h postinfestation on days 21 and 28. Time to ≥ 90% efficacy following new infestations consistently occurred 24-48 h earlier for lotilaner compared with sarolaner or afoxolaner.

CONCLUSIONS

Credelio (lotilaner) has a more rapid onset of acaricidal activity against A. americanum than Simparica Trio (sarolaner-moxidectin-pyrantel) and NexGard (afoxolaner). Only lotilaner's speed of tick kill is sustained throughout the dosing period.

Mathematical model of Ehrlichia chaffeensis transmission dynamics in dogs

Ehrlichia chaffeensis is a tick-borne disease transmitted by ticks to dogs. Few studies have mathematical modelled such tick-borne disease in dogs, and none have developed models that incorporate different ticks' developmental stages (discrete variable) as well as the duration of infection (continuous variable). In this study, we develop and analyze a model that considers these two structural variables using integrated semigroups theory. We address the well-posedness of the model and investigate the existence of steady states. The model exhibits a disease-free equilibrium and an endemic equilibrium. We calculate the reproduction number (T 0 ). We establish a necessary and sufficient condition for the bifurcation of an endemic equilibrium. Specifically, we demonstrate that a bifurcation, either backward or forward, can occur at T 0 = 1 , leading to the existence, or not, of an endemic equilibrium even when T 0 < 1 . Finally, numerical simulations are employed to illustrate these theoretical findings.

Association between vector-borne pathogen seroprevalence in shelter-housed and owned dog populations in the contiguous United States of America

Domestic dogs are susceptible to numerous vector-borne pathogens that are of significant importance for their health. In addition to being of veterinary importance, many of these pathogens are zoonotic and thus may pose a risk to human health. In the USA, owned dogs are commonly screened for exposure to or infection with several canine vector-borne pathogens. Although the screening data are widely available to show areas where infections are being diagnosed, testing of owned dogs is expected to underestimate the actual prevalence in dogs that have no access to veterinary care. The goal of this study was to measure the association between the widely available data from a perceived low-risk population with temporally and spatially collected data from shelter-housed dog populations. These data were then used to extrapolate the prevalence in dogs that generally lack veterinary care. The focus pathogens included Dirofilaria immitis, Ehrlichia spp., Anaplasma spp., and Borrelia burgdorferi. There was a linear association between the prevalence of selected vector-borne pathogens in shelter-housed and owned dog populations and, generally, the data suggested that prevalence of heartworm (D. immitis) infection and seroprevalence of Ehrlichia spp. and B. burgdorferi are higher in shelter-housed dogs, regardless of their location, compared with the owned population. The seroprevalence of Anaplasma spp. was predicted to be higher in areas that have very low to low seroprevalence, but unexpectedly, in areas of higher seroprevalence within the owned population, the seroprevalence was expected to be lower in the shelter-housed dog population. If shelters and veterinarians make decisions to not screen dogs based on the known seroprevalence of the owned group, they are likely underestimating the risk of exposure. This is especially true for heartworm. With this new estimate of the seroprevalence in shelter-housed dogs throughout the USA, shelters and veterinarians can make evidence-based informed decisions on whether testing and screening for these pathogens is appropriate for their local dog population. This work represents an important step in understanding the relationships in the seroprevalences of vector-borne pathogens between shelter-housed and owned dogs, and provides valuable data on the risk of vector-borne diseases in dogs.

Spatial and risk factor analyses of vector-borne pathogens among shelter dogs in the Eastern United States

BACKGROUND

Vector-borne infections pose significant health risks to humans, domestic animals, and wildlife. Domestic dogs (Canis lupus familiaris) in the United States may be infected with and serve as sentinel hosts for several zoonotic vector-borne pathogens. In this study, we analyzed the geographical distribution, risk factors, and co-infections associated with infection with Ehrlichia spp., Anaplasma spp., Borrelia burgdorferi, and Dirofilaria immitis in shelter dogs in the Eastern United States.

METHODS

From 2016 to 2020, blood samples from 3750 shelter dogs from 19 states were examined with IDEXX SNAP® 4Dx® Plus tests to determine the seroprevalence of infection with tick-borne pathogens and infection with D. immitis. We assessed the impact of factors including age, sex, intact status, breed group, and location on infection using logistic regression.

RESULTS

The overall seroprevalence of D. immitis was 11.2% (n = 419/3750), the seroprevalence of Anaplasma spp. was 2.4% (n = 90/3750), the seroprevalence of Ehrlichia spp. was 8.0% (n = 299/3750), and the seroprevalence of B. burgdorferi was 8.9% (n = 332/3750). Regional variation in seroprevalence was noted: D. immitis (17.4%, n = 355/2036) and Ehrlichia spp. (10.7%, n = 217/2036) were highest in the Southeast while seroprevalence for B. burgdorferi (19.3%, n = 143/740) and Anaplasma spp. (5.7%, n = 42/740) were highest in the Northeast. Overall, 4.8% (n = 179/3750) of dogs had co-infections, the most common of which were D. immitis/Ehrlichia spp. (1.6%, n = 59/3750), B. burgdorferi/Anaplasma spp. (1.5%, n = 55/3750), and B. burgdorferi/Ehrlichia spp. (1.2%, n = 46/3750). Risk factors significantly influenced infection across the evaluated pathogens were location and breed group. All evaluated risk factors were significant for the seroprevalence of D. immitis antigens.

CONCLUSIONS

Our results demonstrate a regionally variable risk of infection with vector-borne pathogens in shelter dogs throughout the Eastern United States, likely due to varying distributions of vectors. However, as many vectors are undergoing range expansions or other changes in distribution associated with climate and landscape change, continued vector-borne pathogen surveillance is important for maintaining reliable risk assessment.

Preventive healthcare among dogs and cats in Chile is positively associated with emotional owner-companion animal bond and socioeconomic factors

Global companion animal population has been increasing as well as the number of dogs and cats being considered as a family member. However, it is unclear whether this close relationship could be associated with higher preventive healthcare in companion animals. Using data from 7,048 questionnaires of dogs and 3,271 of cats from the First National Study on Responsible Companion Animal Ownership, we estimated the proportion of preventive healthcare in companion animals of Chile. We also conducted a general linear mixed-effect regression model to identify socioeconomic factors and indicators of the emotional owners-companion animal bond that could influence owners' practices related to vaccination, parasite control, and veterinary visits. Based on the owner's answers, Chile has a satisfactory overall rates of parasite control (71%) and annual veterinary visits (65%) but a low vaccination coverage of both dogs (39%) and cats (25%). 'Purebred', 'live in urban areas', 'acquired by monetary compensation', and 'dog species' were associated with a higher probability of preventive healthcare in companion animals. Conversely, this probability was lower among senior animals compared to adults, males, and those owned by the Silent Generation or Baby Boomers (i.e., owners born before 1964). 'Sleeping inside', 'acquired for an emotional reason' (e.g., companionship), and 'considered a family member' were positively associated with at least one of assessed preventive measures. Our findings suggest that emotional owner-companion animal bonds could positively impact the frequency and quality of preventive healthcare in dogs and cats. However, owners who totally disagreed that a companion animal is a "family member" were also associated with a higher likelihood of vaccination uptake and veterinary visits for their animals. This highlights that owner's compliance with veterinary preventive healthcare is multifactorial. Chile has a high prevalence of infectious diseases circulating among dogs and cats and increasingly close contacts between owners and companion animals due to emotional bonds. Thus, our study calls for One Health approaches to reduce the risks of cross-species disease transmission. Specifically, increasing vaccination coverage of companion animals in Chile is the most urgent preventive measure needed, especially among cats, males, and older animals. Expand preventive healthcare among dogs and cats will promote public and animal health, including local wildlife that is susceptible to infectious diseases circulating in companion animals.

Arthropod-Borne Pathogens in Wild Canids

Wild canids, as well as other wild animal species, are largely exposed to bites by ticks and other hematophagous vectors where the features favoring their presence and spread are found in wooded and semi-wooded areas. Much of the information about arthropod-borne infections concerns domestic and companion animals, whereas data about these infections in wild canids are not exhaustive. The present study is a narrative review of the literature concerning vector-borne infections in wild canids, highlighting their role in the epidemiology of arthropod-borne bacteria and protozoa.

Triangulating the New Frontier of Health Geo-Data: Assessing Tick-Borne Disease Risk as an Occupational Hazard among Vulnerable Populations

Determining interventions to combat disease often requires complex analyses of spatial-temporal data to improve health outcomes. For some vulnerable populations, obtaining sufficient data for related analyses is especially difficult, thus exacerbating related healthcare, research, and public health efforts. In the United States (U.S.), migrant and seasonal workers are especially affected in this regard, with data on health interventions and outcomes largely absent from official sources. In response, this study offers a multi-modal approach that involves triangulating geographically specified health data that incorporate reports on canine tick species, Lyme disease (LD) incidence, and patient symptom severity indicating potential subsequent disease burden. Spatial alignment of data at the U.S. county level was used to reveal and better understand tick-borne disease (TBD) incidence and risk among the identified populations. Survey data from migrant and seasonal workers in Texas were employed to determine TBD risk based on symptoms, occupations, and locations. Respondents who were found to have a higher likelihood of a TBD were also considerably more likely to report the most common symptoms of LD and other TBDs on the Horowitz Multiple Systemic Infectious Disease Syndrome Questionnaire. Those in the highly likely scoring group also reported more poor health and mental health days. Overall, a notable number of respondents (22%) were likely or highly likely to have a TBD, with particular relevance attributed to county of residence and living conditions. Also of note, almost a third of those reporting severe symptoms had received a previous Lyme disease diagnosis. These findings underscore the need for further surveillance among vulnerable populations at risk for TBDs.

A newly developed droplet digital PCR for Ehrlichia canis detection: comparisons to conventional PCR and blood smear techniques

Canine monocytic ehrlichiosis caused by Ehrlichia canis infection is a life-threatening vector-borne disease in dogs worldwide. Routine blood smear has very low sensitivity and cannot accurately provide a quantitative result. Conventional PCR (cPCR) and real-time PCR (qPCR) are widely used as molecular methods for E. canis detection. qPCR is quantitative but relies on standard curves of known samples. To overcome this difficulty, this study developed a new E. canis quantitative detection method, using droplet digital polymerase chain reaction (ddPCR). ddPCR was evaluated against cPCR and blood smears. PCR amplicons and genomic DNA (gDNA) from 12 microscopic positive samples were used to identify the limits of detection (LODs) in ddPCR and cPCR. Our ddPCR was assessed in 92 field samples, it was compared with cPCR and blood smears. ddPCR showed LOD = 1.6 copies/reaction, or 78 times more sensitive than cPCR (LOD = 126 copies/reaction), using PCR amplicons as a template, whereas both ddPCR and cPCR had equal LODs at 0.02 ng gDNA/reaction. In addition, ddPCR had 100% sensitivity and 75% specificity for E. canis detection compared to cPCR and no cross-reaction with other blood pathogens was observed. ddPCR identified more positive samples than cPCR and blood smear. ddPCR improved the overall performance of E. canis detection, with a better LOD and comparable sensitivity and specificity to cPCR. The technique might be helpful for diagnosis of E. canis in light infection, evaluating the number of E. canis and follow-up after treatment.

Moonlighting in Rickettsiales: Expanding Virulence Landscape

The order Rickettsiales includes species that cause a range of human diseases such as human granulocytic anaplasmosis (Anaplasma phagocytophilum), human monocytic ehrlichiosis (Ehrlichia chaffeensis), scrub typhus (Orientia tsutsugamushi), epidemic typhus (Rickettsia prowazekii), murine typhus (R. typhi), Mediterranean spotted fever (R. conorii), or Rocky Mountain spotted fever (R. rickettsii). These diseases are gaining a new momentum given their resurgence patterns and geographical expansion due to the overall rise in temperature and other human-induced pressure, thereby remaining a major public health concern. As obligate intracellular bacteria, Rickettsiales are characterized by their small genome sizes due to reductive evolution. Many pathogens employ moonlighting/multitasking proteins as virulence factors to interfere with multiple cellular processes, in different compartments, at different times during infection, augmenting their virulence. The utilization of this multitasking phenomenon by Rickettsiales as a strategy to maximize the use of their reduced protein repertoire is an emerging theme. Here, we provide an overview of the role of various moonlighting proteins in the pathogenicity of these species. Despite the challenges that lie ahead to determine the multiple potential faces of every single protein in Rickettsiales, the available examples anticipate this multifunctionality as an essential and intrinsic feature of these obligates and should be integrated into available moonlighting repositories.

Ticks and Tick-Borne Pathogens in Domestic Animals, Wild Pigs, and Off-Host Environmental Sampling in Guam, USA

Background: Guam, a United States of America (USA) island territory in the Pacific Ocean, is known to have large populations of ticks; however, it is unclear what the risk is to wildlife and humans living on the island. Dog (Canis familiaris), cat (Felis catus), and wild pig (Sus scrofa) sentinels were examined for ticks, and environmental sampling was conducted to determine the ticks present in Guam and the prevalence of tick-borne pathogens in hosts.

Methods and Results: From March 2019-November 2020, ticks were collected from environmental sampling, dogs, cats, and wild pigs. Blood samples were also taken from a subset of animals. A total of 99 ticks were collected from 27 environmental samples and all were Rhipicephalus sanguineus, the brown dog tick. Most ticks were collected during the dry season with an overall sampling success rate of 63% (95% CI: 42.4–80.6). 6,614 dogs were examined, and 12.6% (95% CI: 11.8–13.4) were infested with at least one tick. One thousand one hundred twelve cats were examined, and six (0.54%; 95% CI: 0.20–1.1) were found with ticks. Sixty-four wild pigs were examined and 17.2% (95% CI: 9.5–27.8) had ticks. In total, 1,956 ticks were collected and 97.4% of ticks were R. sanguineus. A subset of R. sanguineus were determined to be the tropical lineage. The other tick species found were Rhipicephalus microplus (0.77%), Amblyomma breviscutatum (0.77 %), and a Haemaphysalis sp. (0.51%). Blood samples from 136 dogs, four cats, and 64 wild pigs were tested using polymerase chain reaction (PCR) and DNA sequencing methods. Five different tick-borne pathogens with the following prevalences were found in dogs: Anaplasma phagocytophilum 5.9% (95% CI: 2.6–11.3); Anaplasma platys 19.1% (95% CI: 12.9–26.7); Babesia canis vogeli 8.8% (95% CI: 4.6–14.9); Ehrlichia canis 12.5% (95% CI: 7.5–19.3); Hepatozoon canis 14.7% (95% CI: 9.2–28.8). E. canis was detected in one cat, and no tick-borne pathogens were detected in wild pigs. Overall, 43.4% (95% CI: 34.9–52.1) of dogs had at least one tick-borne pathogen. Serological testing for antibodies against Ehrlichia spp. and Anaplasma spp. showed prevalences of 14.7% (95% CI: 9.2–28.8) and 31.6% (95% CI: 23.9–40), respectively.

Conclusion: Four different tick species were found in Guam to include a Haemaphysalis sp., which is a previously unreported genus for Guam. Dogs with ticks have a high prevalence of tick-borne pathogens which makes them useful sentinels.

Retrospective analysis of canine monocytic ehrlichiosis in Thailand with emphasis on hematological and ultrasonographic changes

Background and Aim: Canine monocytic ehrlichiosis (CME) is a tropical endemic tick-borne disease that causes fatality or chronic infection involving many organs in dogs. This study aimed to examine the prevalence, risk factors, and hematological and ultrasonographic changes in the liver, gallbladder, kidneys, and spleen following CME infection. Materials and Methods: This retrospective study used 30,269 samples collected from dogs at the hematology section of the pathology unit of a university veterinary hospital and 35 samples collected from dogs at the diagnostic imaging unit. CME was determined using the buffy coat smear method. Data were analyzed using descriptive statistics and odds ratios. Results: CCl4 The data revealed that the average yearly prevalence of CME was 1.32%. Risk factors contributing to CME infection were a tick on the body during physical examination, lack of ectoparasite control, and outdoor living. All 148 dogs with CME infection had low platelet counts. The percentages of CME-infected dogs with elevated serum alanine aminotransferase, alkaline phosphatase, and both enzymes above the normal range were 33.6%, 65.9%, and 29.8%, respectively. The rates for elevated serum levels of blood urea nitrogen, creatinine, and both compounds were 33.1%, 19.1%, and 17.3%, respectively. The most common ultrasonographic changes were liver abnormalities (hyperechogenicity or hypoechogenicity, hepatomegaly, and hypoechoic nodules), hyperechogenicity of the kidneys, and an enlarged spleen. These ultrasonographic changes were consistent with the hematology results, which showed a greater elevation of serum liver enzyme levels than renal enzymes. Conclusion: Ultrasonographic changes during CME infection and after treatment with doxycycline can help to monitor and identify persistent pathological changes in the target organs resulting from immune response to CME.

Epidemiologic, Clinical and Immunological Consequences of Co-Infections during Canine Leishmaniosis

Simple Summary

Canine leishmaniosis (CanL), the most severe, visceralizing form of disease caused by Leishmania infantum transmitted by phlebotomine sand flies. CanL is frequently diagnosed in the Mediterranean basin and South America, although it is also found in other regions, including the United States (U.S.). Dogs in these regions are at risk for co-infections, prominently tick-borne diseases. Our review examines epidemiologic, clinical, and immunologic mechanisms found during the most common eight CanL co-infections reported in published literature. Co-infections alter immunologic processes and disease progression impacting CanL diagnosis, therapeutic responses, and prognosis.

Abstract

Canine leishmaniosis (CanL) is a vector-borne, parasitic disease. CanL is endemic in the Mediterranean basin and South America but also found in Northern Africa, Asia, and the U.S. Regions with both competent sand fly vectors and L. infantum parasites are also endemic for additional infectious diseases that could cause co-infections in dogs. Growing evidence indicates that co-infections can impact immunologic responses and thus the clinical course of both CanL and the comorbid disease(s). The aim for this review is to summarize epidemiologic, clinical, and immunologic factors contributing to eight primary co-infections reported with CanL: Ehrlichia spp., Anaplasma spp., Borrelia spp., Babesia spp., Trypanosoma cruzi, Toxoplasma gondii, Dirofilaria immitis, Paracoccidioides braziliensis. Co-infection causes mechanistic differences in immunity which can alter diagnostics, therapeutic management, and prognosis of dogs with CanL. More research is needed to further explore immunomodulation during CanL co-infection(s) and their clinical impact.

Invasive woody plants as foci of tick-borne pathogens: eastern redcedar in the southern Great Plains

Habitat preference and usage by disease vectors are directly correlated with landscapes often undergoing anthropogenic environmental change. A predominant type of land use change occurring in the United States is the expansion of native and non-native woody plant species in grasslands, but little is known regarding the impact of this expansion on regional vector-borne disease transmission. In this study, we focused on the impact of expanding eastern redcedar (Juniperus virginiana; ERC) and tested two hypotheses involving relationships between habitat preferences of adult tick species in rural habitats in central Oklahoma. Using CO₂ traps, we collected ticks from two densities of ERC and grassland and screened adult ticks for the presence of pathogen DNA. We found support for our first hypothesis with significantly more Amblyomma americanum (Linnaeus) and Dermacentor variabilis (Say) collected in ERC habitats than in grassland. Our second hypothesis was also supported, as Ehrlichia- and Rickettsia-infected A. americanum were significantly more likely to be collected from ERC habitats than grassland. As the first evidence that links woody plant encroachment with important tick-borne pathogens in the continental United States, these results have important ramifications involving human and companion animal risk for encountering pathogen-infected ticks in the southern Great Plains.

Trypanosoma cruzi co-infections with other vector borne diseases are frequent in dogs from the pacific coast of Ecuador

Dogs are a reservoir for Chagas disease, caused by Trypanosoma cruzi (T. cruzi), and other companion vector-borne diseases, including ehrlichiosis (Ehrlichia canis and Ehrlichia ewingii), anaplasmosis (Anaplasma phagocytophilum and Anaplasma platys), dirofilariasis (Dirofilaria immitis) and Lyme disease (Borrelia burgdorferi). This study has two key objectives: 1) to determine seroreactivity against T. cruzi in dogs from the town of Colón, in Portoviejo city, in the central coast of Ecuador; and 2) to establish the coinfection frequency of other companion vector-borne diseases in dogs positive for T. cruzi. Antibodies against T. cruzi were detected using two enzyme-linked immunosorbent assays. Diagnostic consensus between ELISA tests was established using the Cohen's Kappa coefficient. Other haemoparasitic diseases were detected using the IDEXX SNAP® 4Dx® kit in dogs previously diagnosed as T. cruzi-seropositive. From 84 dogs sampled, 57.14% (48/84) tested positive for T. cruzi. Co-infection analysis of 25 dogs positive for T. cruzi revealed antibodies also against Ehrlichia spp. (48%), Anaplasma spp. (28%), and Dirofilaria immitis (12%). These results provide a novel perspective regarding the status of these pathogens which co-infect dogs in Colón. Since all these pathogens are zoonotic, our findings should warn regional health authorities to implement sanitary programs, to better prevent and control vectors associated to these pathogens. On the other hand, human and veterinarian doctors, should consider that patients with a cardiac infection condition could be suffering co-infections with two or more vector transmitted pathogens.

Demographic and Pathogens of Domestic, Free-Roaming Pets and the Implications for Wild Carnivores and Human Health in the San Luis Region of Costa Rica

Habitat loss and degradation, restricted ranges, prey exploitation, and poaching are important factors for the decline of several wild carnivore populations and additional stress from infectious agents is an increasing concern. Given the rapid growth of human populations in some regions like Costa Rica, pathogens introduced, sustained, and transmitted by domestic carnivores may be particularly important. To better understand the significance of domestic carnivore pathogens for wildlife, we determine the prevalence of infection and possible mechanisms for contact between the two groups. The demographics, role in the household, and pathogens of pet dogs and cats was studied during three annual spay/neuter clinics in San Luis, Costa Rica. Most dogs were owned primarily as pets and guard animals, but ~10% were used for hunting. Cats were owned primarily as pets and for pest control. Both roamed freely outdoors. We detected high prevalences of some pathogens (e.g., carnivore protoparvovirus 1 and Toxoplasma gondii). Some pathogens are known to persist in the environment, which increases the probability of exposure to wild carnivores. This study demonstrated that domestic pets in San Luis, home to a number of protected and endangered wildlife species, are infected with pathogens to which these wild species are potentially susceptible. Additionally, results from our questionnaire support the potential for domestic and wild animal contact, which may result in disease spillover.