Domestic Cat Populations Research Articles

Feline foamy virus seroprevalence and demographic risk factors in stray domestic cat populations in Colorado, Southern California and Florida, USA.

ObjectivesOur study aim was to document the seroprevalence and associated risk factors of feline foamy virus (FFV) infection in domestic cat populations presented to animal shelters located in Southern California, Colorado and Florida, USA.MethodsWe used a glutathione S-transferase capture ELISA targeting the FFV Gag antigen to screen domestic cat serum collected from cats with unknown owners at eight different animal shelters from Colorado (n = 105, three shelters), Southern California (n = 172, three shelters) and Florida (n = 31, two shelters). χ2 statistics determined location effect on seroprevalence. Bayesian generalized linear models were used to explore age and sex as potential risk factors for infection.ResultsFFV seroprevalence was 64.0% across all locations. Seroprevalence by location was as follows: Southern California 75.0%, Colorado 52.4% and Florida 41.9%, with Southern California’s seroprevalence being significantly higher. Age had a significant effect on model fit for all locations, with adults having a higher probability of being infected. In Colorado, sex also had a significant effect on model fit, with males having a higher probability of being infected.Conclusions and relevanceWe have documented that FFV is extremely common in stray domestic cat populations across varied geographic and ecological niches throughout the USA. Adult cats are at a higher FFV infection risk than young cats. FFV has been associated with a higher risk of other retroviral infections and has been implicated in several chronic diseases of cats. Additional epidemiological and clinical studies are warranted to investigate the potential impacts of FFV on domestic cat health.

Unowned Free-Roaming Domestic Cats: Reflection of Animal Welfare and Ethical Aspects in Animal Laws in Six European Countries

Abstract Besides the population of pet cats, another feline population that has regular and frequent relationships with the human population, is represented by unowned, free-roaming domestic cats. It is incontestable that part of human beings is responsible for the growing number of unwanted cats. The problems raised by the existence of free-roaming cat population range from acoustic and hygienic nuisance (because of loud vocalizations during the breeding season and bad smell due to sprayed urine from tomcats) to public health threat (because of the potential spread of zoonotic diseases and of diseases to pet cats and other species), to predation of wildlife (it can cause disruption of ecosystems). Undoubtedly, unowned free-roaming cat population has to be managed but, in the third millennium, human control strategies have to have an ethical dimension. In this paper, we propose an analysis of the National Laws in France, Spain, UK, Austria, Portugal and Italy. Based on the knowledge of domestic cat behavior, we suggest that when the TNR strategy for controlling domestic cat populations is applied by law in the mentioned countries, the basic needs and welfare of the species are respected.

Feline Foamy Virus is Highly Prevalent in Free-Ranging Puma concolor from Colorado, Florida and Southern California.

Feline foamy virus (FFV) is a retrovirus that has been detected in multiple feline species, including domestic cats (Felis catus) and pumas (Puma concolor). FFV results in persistent infection but is generally thought to be apathogenic. Sero-prevalence in domestic cat populations has been documented in several countries, but the extent of viral infections in nondomestic felids has not been reported. In this study, we screened sera from 348 individual pumas from Colorado, Southern California and Florida for FFV exposure by assessing sero-reactivity using an FFV anti-Gag ELISA. We documented a sero-prevalence of 78.6% across all sampled subpopulations, representing 69.1% in Southern California, 77.3% in Colorado, and 83.5% in Florida. Age was a significant risk factor for FFV infection when analyzing the combined populations. This high prevalence in geographically distinct populations reveals widespread exposure of puma to FFV and suggests efficient shedding and transmission in wild populations.

Cat Demographics & Impact on Wildlife in the USA, the UK, Australia and New Zealand: Facts and Values

Abstract The estimated populations of domestic cats in the USA, whether pets, stray or feral, vary widely and have changed significantly over the past forty to fifty years. Accurate estimates of these populations are necessary to determine appropriate policy responses to calls to control domestic cats and to determine the impact of domestic cats on wildlife populations. Domestic cat predation on wild animals is being hotly debated in Australia, New Zealand and the USA (but much less so in the UK). The paper explores some of the different policy approaches being promoted in each country and examines the status of cats in each country. For example, although there is strong movement to control cat predation in New Zealand, the country also has the highest relative (to humans) population of pet cats in the world, despite the vulnerability of native animals to predation by introduced carnivores.

High Seroprevalence of Toxoplasma gondii in an Urban Caracal (Caracal caracal) Population in South Africa

We investigated Toxoplasmosis gondii antibody seroprevalence in free-ranging caracals (Caracal caracal) in Cape Town, South Africa, from 2014 to 2017. Seropositivity was 83% (24/29), which is substantially higher than that detected in sympatric feral domestic cat (Felis catus) populations. The impact of this pathogen on local human and wildlife communities may be of concern.

Occurrence of zoonotic Enterocytozoon bieneusi in cats in Brazil.

Enterocytozoon bieneusi is an opportunistic intestinal pathogen that infects humans and a wide variety of animals worldwide. Our aim in this study was to investigate the occurrence of E. bieneusi in a domestic cat population in Campo Grande, Mato Grosso do Sul, Brazil. Sixty fecal samples from diarrheic cats were subjected to polymerase chain reaction (PCR) and the amplicons were sequenced for identification. E. bieneusi was detected in two samples (3.3%), both identified as genotype D. This genotype has already been reported in animals and humans and is considered a zoonotic genotype. Our findings represent the first report of E. bieneusi in domestic cats in Brazil, reinforcing the importance of identifying this agent as a source of infection in animals and humans.

Orthopoxvirus Seroprevalence in Cats and Veterinary Personnel in North-Eastern Italy in 2011

Orthopoxviruses (OPV) are emerging zoonotic pathogens, and an increasing number of human infections is currently reported in Europe and in other continents, warranting heightened attention on this topic. Following two OPV infections reported in veterinarians scratched by sick cats in 2005 and 2007 in North-Eastern-Italy, involving a previously undescribed OPV, a similar strain was isolated by a sick cat from the same territory in 2011, i.e., 6 years later, raising attention on OPV circulation in this region. A surveillance program was launched to assess the OPV seroprevalence among the veterinarians working in local veterinary clinics and in the local wild and domestic cat population; seroprevalence was 33.3% in veterinarians and 19.5% in cats. Seroprevalence in cats was unevenly distributed, peaking at 40% in the area where OPV-infected cats had been observed.

Breast cancer in the population of cats in Rostov region

This paper presents the results of the study of various pathomorphological forms of breast tumors in the population of domestic cats of the Rostov region. 73247 case histories were analyzed in 8 leading veterinary clinics of Rostov-on-Don and Bataysk city, and also 30 resections of a breast were made with the subsequent histological research. The incidence of breast tumors in the population of cats of the Rostov region in 2018 was 438 animals per 100000. According to the results of 187 cytological findings, “malignant neoplasm” was diagnosed in 53% of cases (48% - carcinoma, 5% - sarcoma). The histological examination revealed malignant tumors in 80% of cases (77% - invasive nonspecific carcinoma, 3% – malignant leaf-shaped tumor). Taking into account the fact that about 1.5(±76 thousand) million cats live in the Rostov region, it can be assumed that 0.44% (p-95%, confidence interval 0.38%-0.50%) will have a breast tumor, about 80% (p-95%, confidence interval 55%-94%) of which will be malignant.

Isolation and phylogenetic analysis of feline calicivirus in Siberia.

The results of the study of the distribution of calicivirus infection in a population of domestic cats of different breeds, contained individually or the group method, the virus isolation in the cell culture and a comparative phylogenetic analysis of their nucleotide sequences with published sequences of reference feld and vaccine strains of Feline calicivirus (FCV) from other countries: USA, Germany, Japan, China and Korea are presented. Clinical signs of infection were found in 14.3% of the animals examined. After several passages in the primary kidney cells of the kitten embryo, seven cytopathogenic isolates FCV were isolated: 1 - from a cat with an acute infection, 5 - subclinical infection, 1 - systemic infection. They were adapted to continuous FK-81 cells in which they reached a maximum infectious activity of 10.0 ± 1.15 lg TCD 50 / cm3. Based on the sequence analysis of the open reading frame 2 region of the viral genome Eshli strain showed a close relationship with strain KM016908 from China with the identity of the nucleotide sequences between them of 81.0%. The results of the investigations showed that FCV isolates obtained from animals on the territory of Siberia are genetically different from strains included to imported vaccines used to prevent disease in Russian Federation and also among themselves. This causes a decrease in the effectiveness of preventive measures. In nurseries that do not have contacts and connections between themselves but located in the same geographic region FCV populations may have some genetic differences. A close relationship of some feld isolates with strains from other countries geographically located so far from the Siberian region has been revealed. Studies on the molecular epizootology of caliciviruses are important in the development of test systems and the monitoring of the spread of strains in Russia.

Distinguishing the victim from the threat: SNP-based methods reveal the extent of introgressive hybridization between wildcats and domestic cats in Scotland and inform future in situ and ex situ management options for species restoration.

The degree of introgressive hybridization between the Scottish wildcat and domestic cat has long been suspected to be advanced. Here, we use a 35‐SNP‐marker test, designed to assess hybridization between wildcat and domestic cat populations in Scotland, to assess a database of 295 wild‐living and captive cat samples, and test the assumptions of the test using 3,097 SNP markers generated independently in a subset of the data using ddRAD. We discovered that despite increased genetic resolution provided by these methods, wild‐living cats in Scotland show a complete genetic continuum or hybrid swarm structure when judged against reference data. The historical population of wildcats, although hybridized, clearly groups at one end of this continuum, as does the captive population of wildcats. The interpretation of pelage scores against nuclear genetic data continues to be problematic. This is probably because of a breakdown in linkage equilibrium between wildcat pelage genes as the two populations have become increasingly mixed, meaning that pelage score or SNP score alone is poor diagnostic predictors of hybrid status. Until better tools become available, both should be used jointly, where possible, when making management decisions about individual cats. We recommend that the conservation community in Scotland must now define clearly what measures are to be used to diagnose a wildcat in the wild in Scotland, if future conservation action is to be effective.

Cat Cultures and Threefold Modelling of Human-Animal Interactions: on the Example of Estonian Cat Shelters

Interaction between humans and cats in urban environments is subject to dynamic change. Based on the frequency and quality of relations with humans, we can distinguish several populations of domestic cats (Felis catus): pedigree, pet, semi-feral, feral, and pseudo-wild. Bringing together theoretical perspectives of the Tartu school of biosemiotics and ethological studies of animal societies, we distinguish two basic types of cat cultures: the culture of street cats and the humano-cat culture of pets. The difference between these cultures is documented on the level of zoosemiotic interactions, ecological relations, and human representations. We introduce a threefold model of human-animal interactions in urban environments which steer a careful course between the Scylla of realistic ontology and the Charybdis of social constructivism. A case study on Estonian cat shelters illustrates the significance of cultural representations and institutionalized actions in human-cat cohabitation.

Fecal survey of parasites in free-roaming cats in northcentral Oklahoma, United States

Cats can be infected by various intestinal parasites, some that are zoonotic. Although surveys of parasite prevalence in owned and shelter cats have been published, none addressed free-roaming, wild-trapped, domestic cat (Felis catus) populations. An opportunity to determine the prevalence of intestinal parasites in wild-trapped, free-roaming cats in northcentral Oklahoma, United States occurred through a trap-neuter-return (TNR) program conducted at Oklahoma State University, Boren Veterinary Medical Hospital, between February 2015 and April 2016. Approximately 1 g to 5 g of feces was collected from 846 free-roaming cats either from cage traps, when available, or rectally using disposable fecal loops and examined by centrifugal fecal flotation tests with 33% zinc sulfate solution. Parasite infections were confirmed by microscopic detection of eggs, cysts, or oocysts and visual detection of proglottids. Approximately 63.9% (541/846) of free-roaming cats were infected by at least one parasite, and 24.9% (211/846) of cats were infected by multiple parasites. The most common intestinal parasite infections detected were: Toxocara cati (44.6%; 377/846), followed by Alaria (13.4%; 113/846), Ancylostoma (11.2%; 95/846), Cystoisospora (9.7%; 82/846), taeniids (7.7%; 65/846), Dipylidium caninum (4.5%; 38/846), Physaloptera (2.2%; 19/846), Eucoleus aerophilus (1.4%; 12/846), Giardia (1.2%; 10/846), and a small (10-12 μm in diameter) Toxoplasma-like oocyst (0.1%; 1/846). A few ectoparasites, Demodex gatoi (0.5%; 4/846) and Cheyletiella (0.1%; 1/846), were also detected by fecal flotation. Our findings indicate that a higher prevalence of parasite infections occurs in free-roaming cats in Oklahoma than in owned cats, and these free-roaming cats contribute to contamination of the environment with several zoonotic parasites. Regional data on the prevalence of parasites in free-roaming cats can aid in the justification for parasite control programs in owned cats since both can share the same environment and supports the current practice of routine broad-spectrum anthelmintic and ectoparasite treatments for owned cats.

Antibodies anti-trypanosomatides in domestic cats in Paraná: who is at highest risk of infection?

The aim of this study were to detect antibodies anti-Leishmania spp. and anti-Trypanosoma cruzi in two different populations of domestic cats (Felis catus domesticus) from North Paraná referred for surgical castration and to determine which characteristics of the animals studied may be associated with seropositivity. Serum samples from 679 cats were analyzed using enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence antibody test (IFAT) in series. Associations between age, sex, race, year of care and animal group were verified using the simple logistic regression. Percentage of 8.5% (58/679) of cats were positive for Leishmania spp. and 7.6% (51/673) for T. cruzi by the tests ELISA and IFAT. Animals collected by non-governmental animal protection organizations presented more seropositivity for Leishmania spp. (p<0.0001). Results shown that Leishmania spp. and T. cruzi are present in domestic cats in the northern part of the state of Paraná, as well as, owners of non-governmental animal protection organizations may be more exposed to leishmaniasis when compared to other animal owners evaluated in the present study.

Survey of Toxoplasma gondii Exposure in Muskrats in a Relatively Pristine Ecosystem.

Waterborne transmission of Toxoplasma gondii is assumed to be enhanced in areas with human-altered landscapes (e.g., urbanization, agriculture) and increased populations of non-native domestic and feral cats (Felis catus). However, little is known concerning T. gondii exposure risks in more natural watersheds (e.g., reduced human footprint, no domestic or feral cats) to establish a baseline for comparisons. In this study, muskrats (Ondatra zibethicus) were used as sentinels to assess baseline T. gondii exposure in a relatively pristine watershed in the Greater Voyageurs Ecosystem, northern Minnesota, during the summers of 2018-2019. Toxoplasma gondii antibodies were assayed in sera of live-trapped muskrats (n = 70) using a modified agglutination test. None of our samples were positive for T. gondii antibodies (P = 0.00, 95% Wald Score Confidence Interval = 0.00-0.05). This study establishes a baseline to compare T. gondii waterborne transmission risks in other human-modified watersheds.

Human-modified landscape acts as refuge for mammals in Atlantic Forest

Abstract: Human-modified landscapes (HMLs) are composed by small, isolated and defaunated forest fragments, which are surrounded by agricultural and urban areas. Information on species that thrives in these HMLs is essential to direct conservation strategies in local and regional scales. Since HMLs are dominant in the Atlantic Forest, we aimed to assess the mammalian diversity in a HML in southeastern Brazil and to propose conservation strategies. We collected data of terrestrial (small-, medium- and large-sized) and volant mammals in three small forest fragments (10, 14 and 26 ha) and adjacent areas, between 2003 and 2016, using complementary methods: active search, camera trapping, live-traps, mist nets and occasional records (i.e., roadkills). In addition, we used secondary data to complement our species list. We recorded 35 native mammal species (6 small-sized, 16 medium- and large-sized, and 13 bats) and seven exotic species in the HML. The recorded mammal assemblage (non-volant and volant), although mainly composed of common and generalist species, includes three medium- and large-sized species nationally threatened (Leopardus guttulus, Puma concolor and Puma yagouaroundi) and two data deficient species (Galictis cuja and Histiotus velatus), highlighting the importance of this HML for the maintenance and conservation of mammal populations. Despite highly impacted by anthropogenic disturbances, the study area harbors a significant richness of medium- and large-sized mammals, being an important biodiversity refuge in the region. However, this biodiversity is threatened by the low quality of the habitats, roadkills and abundant populations of domestic cats and dogs. Therefore, we stress the need of conservation strategies focusing on the medium- and large-sized mammals as an umbrella group, which could benefit all biodiversity in the landscape. We recommend actions that promotes biological restoration, aiming to increase structural composition and connectivity of the forest fragments, reducing roadkills and controlling the domestic cats and dogs' populations, in order to maintain and improve the diversity of mammals in long-term.

Parámetros demográficos en la población de canes y gatos domésticos en asentamientos humanos del distrito de Ventanilla, Callao-Perú

El estudio tuvo como objetivo determinar indicadores demográficos de la población de canes y gatos domésticos con dueño en asentamientos humanos del distrito de Ventanilla, Callao (Perú). Se realizó un muestreo por conglomerado para seleccionar los grupos poblacionales y un muestreo estratificado y sistemático para seleccionar las viviendas. La información fue recolectada mediante una encuesta. Se calcularon las características demográficas de la tenencia de canes y gatos, y la relación can:persona y gato:persona. El 61.9 y 40.0% de las viviendas poseían canes y gatos, respectivamente. El número de mascotas por vivienda fue de 1.8 para ambas especies. El número de crías en los canes fue de 4.3 y en gatos de 3.1. La tasa de supervivencia estimada de las crías fue de 56.2 ± 3.0% en canes y de 66.4 ± 3.9% en gatos. La esperanza de vida estimada fue de 4.21 ± 0.44 años en canes y de 2.64 ± 0.46 años en gatos. Se estimó que existía 1 can por cada 3.98 personas y 1 gato por cada 5.34 personas. El 23% de encuestados manifestó mantener canes vagabundos en el exterior de las viviendas. Se espera que la información ofrecida sirva a las autoridades de salud para planificar programas de control poblacional y tenencia responsable de animales de compañía en esta población.

Exploring the Gaps in Practical Ethical Guidance for Animal Welfare Considerations of Field Interventions and Innovations Targeting Dogs and Cats.

Simple SummaryLarge populations of domestic dogs and cats are found living, or in close association with humans. They are often targeted by field interventions or innovations to enhance their welfare or to reduce conflict with communities or wildlife. Ethical review is a cornerstone of responsible engagement that aims to promote animal and human wellbeing. For the review process to be robust, identifying and understanding the ethical dilemmas that may be encountered when working with dogs and cats in field contexts, together with their human communities and in multi-stakeholder partnerships would be advantageous. We explored existing guidance from other disciplines (regulated animal research, veterinary and human clinical trials, and research conducted on wildlife) and identified gaps in ethical frameworks that do not adequately address the specific and practical needs of nongovernmental or intergovernmental organizations, government agencies or independent researchers working with dogs and cats in field contexts. Navigating practical ethical concerns in complex, highly variable field contexts necessitates the development of additional resources that can better inform reliable ethical review processes, and subsequently enhance the humaneness and effectiveness of future interventions and innovations.Domestic dogs (Canis lupus familiaris) and cats (Felis silvestris catus) are common species targeted by nongovernmental or intergovernmental organizations, veterinarians and government agencies worldwide, for field interventions (e.g., population management, rabies vaccination programs) or innovations (e.g., development of technologies or pharmaceuticals to improve animal welfare). We have a moral responsibility to ensure that the conduct of this work is humane for dogs or cats, and to consider the human communities in which the animals live. Ethical review is widely accepted as being integral to responsible practice, and it is fundamental to good science that underpins innovation. Despite the necessity of field interventions or innovations to advance the welfare of individuals or populations of animals, we found a lack of specific guidance and review processes to help navigate ethical dilemmas surrounding the conduct of such work. This can be detrimental to the wellbeing of animals and their human communities. Here we identify the gaps in existing ethical frameworks (specifically application of Reduction and Refinement principles, challenges of obtaining meaningful informed consent with variations in the quality of human-animal relationships, and limited resources regarding considerations of local stakeholders), and outline the need for additional tools to promote ethical conduct in the field.

Prevalence of feline immunodeficiency virus and feline leukaemia virus infection in Malaysia: a retrospective study.

ObjectivesFeline ownership is popular and represents the largest segment of the pet population in Malaysia. Most feline owners own, on average, 2–3 cats, with some having >10 cats per household. Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) are two clinically important viral infections in cats. Documenting the prevalence of these diseases in the feline population is important for both veterinarians and the public.MethodsThis was a retrospective study, using data collected from the domestic cat population seen at a 24 h private veterinary hospital in Malaysia, to determine the prevalence of FIV and FeLV in an urban area and risk factors associated with these infections. Between 2010 and 2016, 2230 blood samples were collected and tested for FIV antibodies and FeLV antigen using commercially available ELISA test kits.ResultsIn total, 10.0% (n = 224; 95% confidence interval [CI] 8.80–11.26) were seropositive for FIV; 12.0% (n = 267; 95% CI 10.62–13.32) were seropositive for FeLV; and 2.6% (n = 58; 95% CI 2.01–3.17) were seropositive for both.Conclusions and relevanceThe prevalence of FIV is lower and FeLV higher than previously documented for this region. Because of the immunosuppressive potential of both viruses, client education and use of appropriate control strategies such as routine screening, vaccination and eradication should be considered.

Prevalence and risk factors for cats testing positive for feline immunodeficiency virus and feline leukaemia virus infection in cats entering an animal shelter in New Zealand

AIMSTo estimate the prevalence of cats testing positive for antibodies to feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) antigens in domestic cats entering a New Zealand animal shelter, based on a commercial point-of-care ELISA, to identify risk factors associated with cats testing positive, and to compare the results obtained from the ELISA with those obtained using PCR-based testing.METHODA cross-sectional study was performed on 388 cats entering the Royal New Zealand Society for the Prevention of Cruelty to Animals animal shelter in Auckland, New Zealand between 7 February 2014 and 30 May 2014. Whole blood samples were collected from each cat and tested for FIV antibody and FeLV antigen using a commercial point-of-care ELISA. Information on the signalment and health status of the cat at the time of entry was also recorded. Blood and saliva samples from a subset of cats were tested for FIV and FeLV proviral DNA using a real-time PCR assay.RESULTSOf the 388 cats in the study sample, 146 (37.6%) had been relinquished by owners, 237 (62.4%) were strays, and 5 (1.3%) were of unknown origin. Overall, 53/388 (13.7%) cats tested positive for FIV antibodies and 4/388 (1.0%) were positive for FeLV antigen. Stray cats had a higher FIV seroprevalence than relinquished cats (42/237 (17.8%) vs. 11/146 (7.5%); p=0.008). Of 53 cats that were FIV-seropositive, 51 (96%) tested positive for FIV proviral DNA using PCR testing of blood. Of these 51 cats, 28 (55%) were positive by PCR testing of saliva. Of the four cats that were FeLV antigen-positive by ELISA, two (50%) were positive for FeLV proviral DNA by PCR testing of blood. The odds of a cat being seropositive for FIV were greater for intact compared to desexed cats (OR=3.3; 95% CI=1.6–7.4) and for male compared to female cats (OR=6.5; 95% CI=3.2–14.0).CONCLUSIONS AND CLINICAL RELEVANCEThe seroprevalence for FIV was 14% among cats entering an animal shelter in Auckland, whereas the prevalence of FeLV antigen-positive cats was only 1%. These findings suggest differences in the transmission dynamics of each virus in free-roaming cat populations in New Zealand. Our study also highlights the potential role of desexing cats in reducing transmission of FIV. However, further data from first-opinion veterinary practices are required to confirm that these findings may be generalised to the wider domestic cat population in New Zealand.

Low genetic variation in the MHC class II DRB gene and MHC-linked microsatellites in endangered island populations of the leopard cat (Prionailurus bengalensis) in Japan.

Isolated populations of the leopard cat (Prionailurus bengalensis) on Tsushima and Iriomote islands in Japan are classified as subspecies P. b. euptilurus and P. b. iriomotensis, respectively. Because both populations have decreased to roughly 100, an understanding of their genetic diversity is essential for conservation. We genotyped MHC class II DRB exon 2 and MHC-linked microsatellite loci to evaluate the diversity of MHC genes in the Tsushima and Iriomote cat populations. We detected ten and four DRB alleles in these populations, respectively. A phylogenetic analysis showed DRB alleles from both populations to be closely related to those in other felid DRB lineages, indicating trans-species polymorphism. The MHC-linked microsatellites were more polymorphic in the Tsushima than in the Iriomote population. The MHC diversity of both leopard cat populations is much lower than in the domestic cat populations on these islands, probably due to inbreeding associated with founder effects, geographical isolation, or genetic drift. Our results predict low resistance of the two endangered populations to new pathogens introduced to the islands.