Vertebrates as victims of domestic cats and dogs: ten years of data from an Italian animal rescue centre (2015–2024)

Feralization is the process of domesticated animals returning to the wild and it is considered the counterpart of domestication. Molecular genetic changes are well documented in domesticated organisms but understudied in feral populations. In this study, the genetic differentiation between domestic and feral cats was inferred by analysing whole-genome sequencing data of two geographically distant feral cat island populations, Dirk Hartog Island (Australia) and Kaho’olawe (Hawaii) as well as domestic cats and European wildcats. The study investigated population structure, genetic differentiation, genetic diversity, highly differentiated genes, and recombination rates. Genetic structure analyses linked both feral cat populations to North American domestic and European cat populations. Recombination rates in feral cats were lower than in domestic cats but higher than in wildcats. For Australian and Hawaiian feral cats, 105 and 94 highly differentiated genes compared to domestic cats respectively, were identified. Annotated genes had similar functions, with almost 30% of the divergent genes related to nervous system development in both feral groups. Twenty mutually highly differentiated genes were found in both feral populations. Evolution of highly differentiated genes was likely driven by specific demographic histories, the relaxation of the selective pressures associated with domestication, and adaptation to novel environments to a minor extent. Random drift was the prevailing force driving highly divergent regions, with relaxed selection in feral populations also playing a significant role in differentiation from domestic cats. The study demonstrates that feralization is an independent process that brings feral cats on a unique evolutionary trajectory.

Feralization is the process of domesticated animals returning to the wild and it is considered the counterpart of domestication. Molecular genetic changes are well documented in domesticated organisms but understudied in feral populations. In this study, the genetic differentiation between domestic and feral cats was inferred by analysing whole-genome sequencing data of two geographically distant feral cat island populations, Dirk Hartog Island (Australia) and Kaho'olawe (Hawaii) as well as domestic cats and European wildcats. The study investigated population structure, genetic differentiation, genetic diversity, highly differentiated genes, and recombination rates. Genetic structure analyses linked both feral cat populations to North American domestic and European cat populations. Recombination rates in feral cats were lower than in domestic cats but higher than in wildcats. For Australian and Hawaiian feral cats, 105 and 94 highly differentiated genes compared to domestic cats respectively, were identified. Annotated genes had similar functions, with almost 30% of the divergent genes related to nervous system development in both feral groups. Twenty mutually highly differentiated genes were found in both feral populations. Evolution of highly differentiated genes was likely driven by specific demographic histories, the relaxation of the selective pressures associated with domestication, and adaptation to novel environments to a minor extent. Random drift was the prevailing force driving highly divergent regions, with relaxed selection in feral populations also playing a significant role in differentiation from domestic cats. The study demonstrates that feralization is an independent process that brings feral cats on a unique evolutionary trajectory.

Understanding the role of different species in the transmission of multi-host pathogens, such as rabies virus, is vital for effective control strategies. Across most of sub-Saharan Africa domestic dogs Canis familiaris are considered the reservoir for rabies, but the role of wildlife has been long debated. Here we explore the multi-host transmission dynamics of rabies across south-east Tanzania.Between January 2011 and July 2019, data on probable rabies cases were collected in the regions of Lindi and Mtwara. Hospital records of animal-bite patients presenting to healthcare facilities were used as sentinels for animal contact tracing. The timing, location and species of probable rabid animals were used to reconstruct transmission trees to infer who infected whom and the relative frequencies of within- and between-species transmission.During the study, 688 probable human rabies exposures were identified, resulting in 47 deaths. Of these exposures, 389 were from domestic dogs (56.5%) and 262 from jackals (38.1%). Over the same period, 549 probable animal rabies cases were traced: 303 in domestic dogs (55.2%) and 221 in jackals (40.3%), with the remainder in domestic cats and other wildlife species.Although dog-to-dog transmission was most commonly inferred (40.5% of transmission events), a third of inferred events involved wildlife-to-wildlife transmission (32.6%), and evidence suggested some sustained transmission chains within jackal populations.A steady decline in probable rabies cases in both humans and animals coincided with the implementation of widespread domestic dog vaccination during the first 6 years of the study. Following the lapse of this program, dog rabies cases began to increase in one of the northernmost districts. Synthesis and applications. In south-east Tanzania, despite a relatively high incidence of rabies in wildlife and evidence of wildlife-to-wildlife transmission, domestic dogs remain essential to the reservoir of infection. Continued dog vaccination alongside improved surveillance would allow a fuller understanding of the role of wildlife in maintaining transmission in this area. Nonetheless, dog vaccination clearly suppressed rabies in both domestic dog and wildlife populations, reducing both public health and conservation risks and, if sustained, has potential to eliminate rabies from this region.

Domestic dogs (Canis familiaris) and cats (Felis catus) are the most abundant mammalian carnivores worldwide. Given that domestic carnivores rely on human-provided food, their densities are usually independent of prey densities. Nevertheless, underfed pets may need to hunt to meet their energetic and nutritional requirements. We explored the effects of different levels of care (provision of food) of dogs and cats on their predation rates on wild vertebrates in 2 areas of southern Chile. We interviewed cat and dog owners and analyzed prey remains in scats of pets to examine how domestic dogs and cats were managed and to gather information on the wild vertebrates killed and harassed by pets. We used logistic regression to examine the association between pet care and the frequency of wild vertebrate remains in scats. The probability of a dog preying on vertebrates was higher for poorly fed than for adequately fed dogs (odds ratio = 3.7) and for poorly fed than for adequately fed cats (odds ratio = 4.7). Domestic dogs and cats preyed on most endemic and threatened mammals present in the study sites. Our results provide support for the hypothesis that the less care domestic animals receive from owners the higher the probability those animals will prey on wild vertebrates.

The outbreak of human toxoplasmosis can be attributed to ingestion of food contaminated with Toxoplasma gondii. Toxoplasmosis recently increased in domestic and stray dogs and cats. It prompted studies on the zoonotic infectious diseases transmitted via these animals. Sero- and antigen prevalences of T. gondii in dogs and cats were surveyed using ELISA and PCR, and B1 gene phylogeny was analyzed in this study. Toxoplasmosis antibodies were measured on sera of 403 stray cats, 947 stray dogs, 909 domestic cats, and 2,412 domestic dogs collected at nationwide regions, Korea from 2017 to 2019. In addition, whole blood, feces, and tissue samples were also collected from stray cats (1,392), stray dogs (686), domestic cats (3,040), and domestic dogs (1,974), and T. gondii-specific B1 gene PCR was performed. Antibody prevalence of stray cats, stray dogs, domestic cats, and domestic dogs were 14.1%, 5.6%, 2.3%, and 0.04%, respectively. Antigen prevalence of these animals was 0.5%, 0.2%, 0.1%, and 0.4%, respectively. Stray cats revealed the highest infection rate of toxoplasmosis, followed by stray dogs, domestic cats, and domestic dogs. B1 gene positives were 5 of stray cats, and identified to high/moderate pathogenic Type I/III group. These findings enforce that preventive hygienic measure should be strengthened at One Health level in dogs and cats, domestic and stray, to minimize human toxoplasmosis infections.

Whereas hundreds of breeds of domestic dogs are known, only several dozen domestic cat breeds are currently recognized, and the ferret is not classified into specific breeds. We studied pre- and postnatal patterns of development and growth in the domesticated forms of these three carnivoran species. We present the most comprehensive staging system for domestic dog embryos to date and define qualitative characters for phylogenetic comparisons. For postnatal development, we present analyses of new and literature measurements of cranial and limb proportions. We analyze changes in the progress of growth among different domestic dog and domestic cat breeds. All three domesticated forms drastically differ in the relative timing of prenatal development. This is correlated with ontogenetic plasticity at birth, which enables artificial selection to act. For postnatal development, we detected a greater shape variance in domestic dog ontogeny when compared to that of the domestic cat. We conclude that ontogenetic preconditions as well as body size constrain the species’ capability for artificial selection in domestic dogs and cats. However, we speculate that the human requirements for functional performance of their domesticates might render some developmental biases substantially. Although ferrets would be preferable for artificial selection given their plastic embryonic development, they have been of less interest for domestication due to their small body size - by which they were already well adapted for hunting in burrows - and due to the fact that other relevant tasks were already assumed by domestic cats and dogs since earlier phases of human cultural evolution.

Domestic cats and dogs are susceptible to H9N2 avian influenza virus

The unprecedented rate of disease emergence across the globe has raised concern among conservationists. Within the last decades there have been many examples of infectious disease-driven mortality of endangered populations, including the chytridiomycosis panzootic in amphibians and morbillivirus infections in marine mammals. These and other events have provided evidence that disease may pose a significant threat to biodiversity (reviewed in Smith, Acevedo-Whitehouse & Pedersen, 2009) and have highlighted the need for control programmes at different levels, from preventing a disease from being introduced or controlling an already-present disease, to completely eradicating the disease (Wobeser, 2002). Programmes aimed at lowering transmission by vaccination or by limiting contact with domestic animals might considerably reduce the risk of disease-related mortality for endangered populations (Pedersen et al., 2007). Lamentably, few such programmes have been fully implemented as part of conservation plans, partly because there is still limited data available to assess disease risks for many wildlife populations; and partly because the required interventions are costly and, in many cases, logistically impractical. As a result, it is difficult to assess the efficacy of disease management measures and determine whether it is necessary, feasible and affordable to develop and implement disease control strategies. In this context, the featured study by Lopez et al. (2009) provides a good example of the importance of a disease management strategy for a critically endangered species and highlights some points that might be relevant to other wildlife disease scenarios. The authors report the outcome of emergency measures to control a feline leukaemia virus (FeLV) epizootic among Iberian lynx. The disease management plan that was implemented to stop the FeLV outbreak from spreading used a multi-pronged approach which included serological surveys, isolation of infected individuals and vaccination of non-infected individuals, as well as selective culling/removal of feral and domestic cats. The authors managed to capture more than 80% of the lynx population and conducted sensitive diagnostic tests to determine the prevalence of the disease and identify suitable candidates for vaccination. This gargantuan effort was sustained for eight months and resulted in the vaccination of a relatively large number of lynxes across the species distribution. The combined measures were reported to be successful in confining the outbreak and preventing a potentially catastrophic outcome for the lynx population in south-western Spain. Lopez and colleagues highlight two issues that must be taken into account for conservation plans. First, it could be argued that as the disease drove the host population below the density threshold needed for persistence the outbreak would have been self-limiting and, thus, may not have needed any control strategy. However, transmission of FeLV is not dependent on population size; rather, it increases with frequency of contacts between infected and susceptible individuals (Fromont et al., 1997). The extremely low population size and small range of the Iberian lynx makes it possible for FeLV to propagate quickly during mating season and potentially kill the entire population. This is further complicated by the fact that, as occurs for most small and isolated populations, the Iberian lynx suffers from low genetic variability and inbreeding (Johnson et al., 2004), which can lead to lower immunocompetence, susceptibility to infection and higher disease severity (Spielman et al., 2004). Moreover, because the lynx appear to have been relatively unexposed to FeLV in the past, the population would expectedly have little, if any, acquired immunity against the infection. Therefore, the timely and concerted disease management strategy reported by Lopez and colleagues is likely to have been essential to contain the epidemic and avoid a catastrophe for this endangered species. The second issue that arises from the featured study relates to the financial cost and intense labour which were obviously needed to implement the disease control programme during the active epidemic. Lopez and colleagues’

Serum samples from 340 pet cats presented to three inner city clinics in Sydney Australia, 68 feral cats from two separate colonies in Sydney, and 329 cattery-confined pedigree and domestic cats in eastern Australia, were collected over a 2-year period and tested for antibodies directed against feline immunodeficiency virus (FIV) using immunomigration (Agen FIV Rapid Immunomigration test) and enzyme-linked immunosorbent assay methods (Snap Combo feline leukaemia virus antigen/FIV antibody test kit, IDEXX Laboratories). Western blot analysis was performed on samples in which there was discrepancy between the results. Information regarding breed, age, gender, housing arrangement and health status were recorded for all pet and cattery-confined cats, while the estimated age and current physical condition were recorded for feral cats. The FIV prevalence in the two feral cat populations was 21% and 25%. The majority of FIV-positive cats were male (60-80%). The FIV prevalence in cattery-confined cats was nil. The prevalence of FIV in the pet cat sample population was 8% (27/340) with almost equal prevalence in 'healthy' (13/170) and 'systemically unwell' (14/170) cats. The age of FIV-positive pet cats ranged from 3 to 19 years; all FIV-positive cats were domestic shorthairs with outside access. The median age of FIV-positive pet cats (11 years) was significantly greater than the median age of FIV-negative pet cats (7.5 years: P<0.05). The prevalence of FIV infection in male pet cats (21/172; 12%) was three times that in female pet cats (6/168; 4%; P<0.05). With over 80% of this pet cat population given outside access and continued FIV infection present in the feral population, this study highlights the need to develop rapid, accurate and cost-effective diagnostic methods that are not subject to false positives created by concurrent vaccination against FIV. This is especially important in re-homing stray cats within animal shelters and monitoring the efficacy of the new vaccine, which has not been challenged against Australian strains. The absence of FIV within cattery-confined cats highlights the value in routine screening and indoor lifestyles. This study provides cogent baseline FIV prevalences in three cat subpopulations which can be used for appraising potential disease associations with FIV in Australia.

Demography of the pet dog and cat population on the island of Ireland and human factors influencing pet ownership

Context Access to effective toxicants and delivery systems that target red foxes (Vulpes vulpes) are likely to be required as part of a management strategy in the event of future red fox incursions into Tasmania. Potential toxicants include sodium fluoroacetate (1080), para-aminopropiophenone (PAPP) and sodium cyanide (NaCN). Aims To assess the risk of three toxicants (1080, PAPP and NaCN) to non-target native Tasmanian mammals and birds and domestic dogs and cats. Methods We identified native Tasmanian mammal and bird species that may potentially consume fox baits, by reviewing the ecological traits of native species and by monitoring 180 buried bait stations with video cameras. We also assess the potential risk to non-target species of dying from a single standard dose of each of the three toxicants. Key results Seven native mammal and 20 native bird species have the potential to consume fox bait. All vertebrates would be susceptible to a single dose of NaCN. Consumption of a single fox bait containing 3 mg 1080 may be lethal to five native mammals, three native birds, and the domestic cat (Felis catus) and dog (Canis familiaris). Consumption of a single fox bait containing 226 mg PAPP may be lethal to the spotted-tailed quoll (Dasyurus maculatus) and the domestic cat and dog. Delivery of toxicants via a mechanical ejector would reduce non-target exposure to toxicants. Conclusions It appears that PAPP would provide a useful alternative to 1080 for use in lethal fox control in Tasmania, either in the event of an incursion or in the eradication of an established population. NaCN is not suitable for broadscale use in Tasmania because of the high susceptibility of all vertebrates to this toxicant. Nevertheless, NaCN would be useful in highly restricted areas in the event of an incursion where carcass recovery is important. The use of a mechanical ejector to target delivery of toxicants to red foxes would reduce non-target risks. Implications Our results clarify theoretical non-target risks from any future fox-poisoning programs in Tasmania and highlight the need for further research on the susceptibility of native species to PAPP as a potential alternative to 1080.

BackgroundHundreds of millions of domestic carnivores worldwide have diverse positive affiliations with humans, but can provoke serious socio-ecological impacts when free-roaming. Unconfined dogs (Canis familiaris) and cats (Felis catus) interact with wildlife as predators, competitors, and disease-transmitters; their access to wildlife depends on husbandry, perceptions, attitudes, and behaviors of pet owners and non-owners.MethodsTo better understand husbandry and perceptions of impacts by unconfined, domestic carnivores, we administered questionnaires (n = 244) to pet owners and non-owners living in one of the last wilderness areas of the world, the Cape Horn Biosphere Reserve, located in southern Chile. We used descriptive statistics to provide demographic pet and husbandry information, quantify free-roaming dogs and cats, map their sightings in nature, and report experiences and perceptions of the impact of free-roaming dogs and cats on wildlife. We corroborated our results with an analysis of prey remains in dog feces (n = 53). With generalized linear models, we examined which factors (i.e., food provisioning, reproductive state, rural/village households, sex, and size) predicted that owned dogs and cats bring wildlife prey home.ResultsThirty-one percent of village dogs (n = 121) and 60% of dogs in rural areas (n = 47) roamed freely day and/or night. Free-roaming dog packs were frequently observed (64% of participants) in the wild, including a feral dog population on Navarino Island. Dogs (31 of 168) brought home invasive muskrats (Ondatra zibethicus) and avian prey, and over half of all cats (27 of 51) brought home mainly avian prey. Birds were also the most harassed wildlife category, affected by one third of all dogs and cats. Nevertheless, dog-wildlife conflicts were hardly recognized (<9% of observed conflicts and suspected problems), and only 34% of the participants thought that cats might impact birds. Diet analysis revealed that dogs consumed livestock (64% of 59 prey occurrences), beavers (Castor canadensis, 14%), and birds (10%). The probability that dogs brought prey to owners’ homes was higher in rural locations and with larger dogs. There was also evidence that cats from rural households and with an inadequate food supply brought more prey home than village cats.DiscussionAlthough muskrat, beavers, and birds were brought home, harassed, or found in dog feces, free-roaming dogs and, to a lesser extent, cats are perceived predominantly in an anthropogenic context (i.e., as pets) and not as carnivores interacting with wildlife. Therefore, technical and legal measures should be applied to encourage neutering, increase confinement, particularly in rural areas, and stimulate social change via environmental education that draws attention to the possibility and consequences of unconfined pet interaction with wildlife in the southernmost protected forest ecoregion of the globe.

Staphylococcus aureus and Staphylococcus pseudintermedius are widespread skin and mucous membrane colonizers and may cause opportunistic infections in humans and animals. This study aimed to identify and characterize methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. pseudintermedius (MRSP) isolates from domestic and stray dogs and cats and pet owners in Malaysia using molecular epidemiology and antimicrobial profiling. Three hundred and fifty oral and nasal swabs were taken from pet and stray dogs and cats and pet owners; all samples were subjected to culture and biochemical tests and polymerase chain reaction; the selected isolates were put through disk diffusion test and multilocus sequence typing. One S. aureus isolate and three S. pseudintermedius isolates were identified as MRSA and MRSP, respectively, of which the MRSA isolate and one of the MRSP isolates showed multidrug resistance and the remaining two MRSP isolates were resistant to one or two antimicrobials. Multilocus sequence typing showed that the MRSA isolate belongs to clonal complex (CC) 789, while for the MRSP isolates, two were in CC45 and one was a singleton. This study is the first study in Malaysia to perform molecular characterization of MRSP isolated from pet dogs and cats and pet owners. The outcomes of this study reveal that even healthy pet dogs and cats and their owners can be carriers of drug-resistant staphylococci, highlighting the role of pets and pet owners as carriers of MRSA and MRSP in Malaysia.

Background and Aim: Staphylococcus aureus and Staphylococcus pseudintermedius are widespread skin and mucous membrane colonizers and may cause opportunistic infections in humans and animals. This study aimed to identify and characterize methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. pseudintermedius (MRSP) isolates from domestic and stray dogs and cats and pet owners in Malaysia using molecular epidemiology and antimicrobial profiling. Materials and Methods: Three hundred and fifty oral and nasal swabs were taken from pet and stray dogs and cats and pet owners; all samples were subjected to culture and biochemical tests and polymerase chain reaction; the selected isolates were put through disk diffusion test and multilocus sequence typing. Results: One S. aureus isolate and three S. pseudintermedius isolates were identified as MRSA and MRSP, respectively, of which the MRSA isolate and one of the MRSP isolates showed multidrug resistance and the remaining two MRSP isolates were resistant to one or two antimicrobials. Multilocus sequence typing showed that the MRSA isolate belongs to clonal complex (CC) 789, while for the MRSP isolates, two were in CC45 and one was a singleton. Conclusion: This study is the first study in Malaysia to perform molecular characterization of MRSP isolated from pet dogs and cats and pet owners. The outcomes of this study reveal that even healthy pet dogs and cats and their owners can be carriers of drug-resistant staphylococci, highlighting the role of pets and pet owners as carriers of MRSA and MRSP in Malaysia. Keywords: antimicrobial resistance, antimicrobial susceptibility testing, methicillin resistance, multilocus sequence typing, public health, zoonotic infections.

Introduction Rabies is an important veterinary and public health disease, and causes thousands of human deaths annually in the low and middle-income countries (LMICs). The aim of this study was to determine the rabies virus biotypes associated with cattle rabies by analyzing lyssavirus-infected brain tissues collected between 2008 and 2018 from the North-West province (South Africa). Methodology A total of 43 rabies-infected brain tissues were subjected to reverse-transcription PCR of the highly variable glycoprotein gene, and the generated amplicons were sequenced. In addition, 20 cattle rabies viruses were subjected to an indirect immunofluorescent antibody test and their reactivity patterns compared to those from commonly-circulating southern African lyssaviruses. Results During the study period (2008–2018), cattle were the most commonly infected host species with rabies virus (42%), followed by domestic dogs (28%), goats (4%), sheep (3%), and a variety of wildlife species including black-backed jackals (13%), yellow mongooses (4%), slender mongooses (3%), duiker (2.1%), honey badgers (1%) and unidentified species (1%). Phylogenetic analysis of the generated nucleotide sequences delineated the rabies viruses into four clades, three belonging to the canid rabies virus biotype. The first clade comprised wildlife, domestic dog and bovine RABVs, and the second and third exclusively jackal and bovine RABVs, linked to dog and jackal RABVs from the commonly dog-endemic regions of South Africa. The fourth clade consisted of cattle RABVs associated with the mongoose rabies biotype. Phylogenetic analyses confirmed very close genetic relationships between dog and jackal RABVs, highlighting the common progenitor and historical introduction of rabies in the country, and cross-species transmission events between domestic and wildlife host species. Antigenic typing, allows us to infer the sources of RABV infection, given that antigenic variants of rabies virus are associated with different rabies cycles and species of terrestrial carnivores in South Africa. Conclusion This study highlighted the transmission routes between domestic (dogs) and wildlife (jackals and mongooses) reservoirs and cattle. Both antigenic and genetic typing suggest interactions between livestock and both domestic and wildlife. Vaccination of dogs remains crucial to break rabies transmission cycles and particularly so in the North West of the country.