Exotic Mammals Research Articles

Retrospective study on the occurrence of Salmonella serotypes in veterinary specimens of Atlantic Canada (2012-2021).

This study aimed to summarize the frequency and the antimicrobial susceptibility profiles of the Salmonella serotypes identified from the specimens of companion animals, livestock, avian, wildlife and exotic species within Atlantic Canada. The retrospective electronic laboratory data of microbiological analyses of a selected subset of samples from 03 January 2012 to 29 December 2021 submitted from various animal species were retrieved. The frequency of Salmonella serotypes identified, and their antimicrobial susceptibility results obtained using the disk diffusion or broth method were analysed. The test results were interpreted according to the Clinical and Laboratory Standards Institute standard. The Salmonella serotypes were identified by slide agglutination (Kauffman-White-Le-Minor Scheme) and/or the Whole Genome Sequencing for the Salmonella in silico Serovar Typing Resource-based identification. Of the cases included in this study, 4.6% (n=154) had at least one Salmonella isolate, corresponding to 55 different serovars. Salmonella isolation was highest from exotic animal species (n=40, 1.20%), followed by porcine (n=26, 0.78%), and canine (n=23, 0.69%). Salmonella subsp. enterica serovar Typhimurium was predominant among exotic mammals, porcine and caprine samples, whereas S. Enteritidis was mostly identified in bovine and canine samples. S. Typhimurium of porcine origin was frequently resistant (>70.0%) to ampicillin. In contrast, S. Typhimurium isolates from porcine and caprine samples were susceptible (>70.0%) to florfenicol. S. Oranienburg from equine samples was susceptible to chloramphenicol, but frequently resistant (>90.0%) to azithromycin. In avian samples, S. Copenhagen was susceptible (>90.0%) to florfenicol, whereas Muenchen was frequently resistant (>90.0%) to florfenicol. S. subsp. diarizonae serovar IIIb:61:k:1,5 of ovine origin was resistant (50.0% isolates) to sulfadimethoxine. No significant changes were observed in the antibiotic resistance profiles across the study years. This report provides data for surveillance studies, distribution of Salmonella serotypes and their antimicrobial resistance among veterinary specimens of Atlantic Canada.

Do exotic invasive mammals disturb the native fauna? Spatiotemporal distribution and overlap between species in a national park of Argentina.

Monitoring the invasive exotic species and their effect on native fauna is fundamental for their effective control. The objective of this research is to evaluate the spatiotemporal distribution and overlap of medium-large-sized fauna in El Palmar National Park, Argentina, to consider potential negative interactions between native and exotic species. Camera traps were distributed in 27 sites between 2017 and 2019. Spatial and temporal overlap was estimated for every pair of exotic-native taxa. With 2673 camera days, two exotic and seven native taxa were recorded. All species were distributed along the extension of the National Park but in different numbers of sites. Exotic axis deer (Axis axis) was recorded in all sites but one, and exotic wild boar (Sus scrofa) occurred at only one-third of the sites surveyed. The occurrence of native mammals ranged between 26% (Geoffroy's cat, Leopardus geoffroyi) and 67% (capybara, Hydrochoerus hydrochaeris). Spatial overlap between native and exotic species was high overall and was higher in winter when species moved over larger areas to look for limited resources. Except for greater rhea (Rhea americana), which was diurnal, all species had crepuscular or nocturnal patterns. Both exotic species had an intermediate/high overlap in their activity pattern with almost all native species, including some species with similar diets, but the hours of their maximum activities did not strictly coincide. However, the existence of differences in the exotic species' activity patterns compared to their patterns in other areas where they inhabit could indicate segregation in daily activity to relax competition.

Identification of Aichivirus in a Pet Rat (Rattus norvegicus) in Italy

We investigated the occurrence of eight potential zoonotic viruses in 91 exotic companion mammals from pet shops in southern Italy via real-time PCR and end-point PCR. The animals were screened for aichivirus, sapovirus, astrovirus, hepatitis A, noroviruses (GI and GII), rotavirus, circovirus, and SARS-CoV-2. Among the nine species of exotic pets studied, only one rat tested positive for aichivirus. The high sequence similarity to a murine kobuvirus-1 strain previously identified in China suggests that the virus may have been introduced into Italy through the importation of animals from Asia. Since exotic companion mammals live in close contact with humans, continuous sanitary monitoring is crucial to prevent the spread of new pathogens among domestic animals and humans. Further investigations on detecting and typing zoonotic viruses are needed to identify emerging and re-emerging viruses to safeguard public health.

Attraction of microarthropods to dung of invasive mammals in meadows of northwestern Patagonia

AbstractThe attractive effect of dung on coprophagous beetle communities and their role in dung degradation are well‐known phenomena. However, little research has been conducted on the recruitment capacity of this substrate for other arthropods, especially those inhabiting the soil. With the aim of beginning to recognize general patterns in these relationships, the influence of the structure and origin of dung from invasive exotic mammals on the recruitment of microarthropods was investigated in two meadows within Nahuel Huapi National Park in southwestern Argentina. Abundance, richness and diversity of microarthropod communities collected on invasive mammal dung were studied. A total of 2478 microarthropods were collected and 52 species were identified. Recruitment of microarthropods on dung of two invasive coprophagic herbivores, the rabbit, Oryctolagus cuniculus and the hare, Lepus europaeus, were compared with two invasive non‐coprophagic mammals, one herbivorous, the red deer, Cervus elaphus and one omnivorous, the wild boar, Sus scrofa. Pellets of S. scrofa showed the highest microarthropod abundance and richness while diversity was greatest on pellets of C. elaphus. Pygmephorid and oribatid mites and springtails were the most abundant. Liposcelis psocopterans and oribatid mites were more abundant on S. scrofa dung. Low similarity was observed when comparing dung of invasive mammals from different sites revealing spatial variability regarding species composition. Based on its more diverse diet, we conclude that S. scrofa dung exerts a strong influence on microarthropod communities by recruiting a greater number of individuals and species than the dung of the remaining invasive mammals.

The enemy of my enemy… Exotic mammals present biotic resistance against invasive alien conifers

Plant invasions are a widespread and recurring phenomenon that cause significant economic and environmental damage. Invasive alien conifers are weeds that are not only costly to manage, but consistently reinvade after management efforts. Understanding how many seeds survive to germinate is a key part in understanding the weed life cycle puzzle. Here we investigated the contribution that seed predators have on reducing invasive alien conifer seed survival across both invaded and uninvaded habitats in Aotearoa New Zealand. We combined quantitative and qualitative experiments to measure seed predation across invaded and uninvaded habitats, as well as to identify which fauna are the most prolific seed predators. We utilised ex-situ empirical evidence with in-situ observations to provide realistic impacts from different seed predator species. We found that introduced mammals, particularly rodents, were the primary seed predators of invasive conifers. Seed predation pressure was highest in herbicide treated invasive alien conifer forests, indigenous beech forests, and managed pasture containing grazing livestock. Indigenous tussock areas support fewer vertebrate seed predators and as a result are particularly vulnerable to conifer invasion. The majority of seed predation occurs within the first two weeks post-dispersal. These results suggest that introduced mammal control operations, which are essential to protect endemic New Zealand species, will likely result in increasing invasive conifer populations by reducing seed predation pressure. Seed predation varies greatly between habitats, suggesting invasion and reinvasion rates are higher in ungrazed areas of lower forest density that support fewer introduced mammals.

Native and exotic small mammals as hosts of Hydatigera taeniaeformis sensu stricto larvae on pig farms of central Argentina: a study of prevalence and phylogenetic relationships

Native and exotic small mammals as hosts of Hydatigera taeniaeformis sensu stricto larvae on pig farms of central Argentina: a study of prevalence and phylogenetic relationships

Beyond hippos: Evidence of an introduced deer in Colombia

More than 18% of the cases of invasive mammals worldwide correspond to South America, including small rodents and large species such as deer and hippos. Among exotic mammals in Colombia, we can mention pigs (Sus scrofa), which are well established, mainly in the Orinoquía region of the country, and more recently, hippos (Hippopotamus amphibius) with a growing area of occurrence in the middle and lower basin of the Magdalena River in the inter-Andean zone. In May 2022, a spotted exotic deer was documented in the area based on direct and indirect observations (photographs and videos) of living individuals and a partial skeleton. The spotted pattern of the photographed adults (absent in native or other exotic deer) and the juvenile individuals and the shape of the antlers show that they are chitals (Axis axis), a species native to Asia. Compared with the white-tailed deer Odocoileus, the largest native deer species in Colombia, the Axis skeleton was one-third bigger, which corroborated the identification. According to local inhabitants’ communications, the number of Axis has increased, and groups of up to 18 individuals have been recorded. This is the first time that exotic deer have been documented in Colombia. Their presence may impact natural regeneration and competitively displace other native herbivores, which calls for the mitigation and control of the population since its establishment and dispersal can be cryptic.

Habitat and food preferences of European rabbits in core and edge populations along the invasion front Patagonia-Monte, Argentina.

The European rabbit Oryctolagus cuniculus is an exotic herbivorous mammal undergoing an active phase of geographical expansion in the arid ecosystems of Argentina. The Adaptive Flexibility Hypothesis states that populations at the range edge (new populations) will exhibit greater flexibility in the use of resources compared with populations located in the range core (older populations). The objective of this work was to compare the rabbit's use of spatial and trophic resources in relation to the establishment time of their populations. The sampling was carried out for 2 years (2017 and 2018) in sites with different establishment times for rabbit populations. Random sampling stratified by type of habitat was applied using 115 fixed strip transects of 1,000 m2 laid out across the study areas. Fresh rabbit signs were recorded in each transect, and environmental and anthropic variables were measured. Our results show that the individuals from the range edge are more selective in the use of habitat than those from the range core. At the microhabitat level, we observed a pattern in the particular components of habitat use by rabbits mainly linked to food availability and proximity to water. From a trophic perspective, rabbits could show flexible adjustment to novel conditions and environments in the range edge. The variability in resource use by the European rabbit confirms its ecological flexibility, pivotal for their advance toward new environments in Argentina.

Factors affecting spatial occupancy and local abundance of the Forest Thrush, Turdus lherminieri, in Guadeloupe forests

The Forest Thrush (FT), Turdus lherminieri, is a secretive, ground-dwelling forest bird species of conservation concern, endemic to only four Caribbean islands. Factors influencing habitat selection and abundance by FT have been seldom documented so far. We assessed variation in the presence and abundance of FT in various forested habitats in Guadeloupe. To that end, we deployed 5-camera-trap arrays over 14 days on 24 different survey stations resulting in 1680 trap days. We observed FT more frequently at camera trap stations where rainforest dominated, with local abundance declining with increasing canopy openness. Furthermore, temperature was the most important factor affecting the presence of FT at our study sites. FT was essentially diurnal, with some activity at dawn and dusk. We document for the first-time spatial co-occurrence between FT and potential mammal predators. FT co-occurred positively with rats and negatively with cats. Although FT is globally listed as near threatened by IUCN, the species the species appeared to be relatively abundant in Guadeloupe, possibly as a consequence of the suspension of hunting since 2014 and/or the almost total protection of the Guadeloupe tropical rainforest. We recommend the use of camera traps to improve knowledge for the conservation status of the species in other part of its area of distribution and to provide additional information on the potential impact of exotic predatory mammals.

Maintaining vegetative structure during weed management sustains birds and an invasive mammal

Weed management often involves active measures to minimize or prevent negative impacts on local wildlife. Approaches include retention of weed structure, altered timing of management to avoid wildlife breeding seasons, and/or the gradual removal of weeds in conjunction with revegetation of native plants. We assess the short‐term impacts of retaining some structural complexity offered by weeds post management to birds and a small mammal in two ecosystems. One ecosystem involves a wetland with an emergent weed, the other a woodland with a sub‐canopy weed. Before‐After‐Reference‐Control‐Impact experiments revealed that assemblage and activity of birds and an invasive small mammal—the only captured in numbers during our study—were minimally altered by weed management. In some instances, we observed the activity of native bird species favoring the use of weeds. Evidence also suggested the weedy sites supported different species assemblages compared to reference sites without weeds. This study indicates that, in the short‐term, retention of weed structure can sustain birds and an exotic mammal that use weeds.

Problem-Oriented Approach in Exotic Companion Mammals.

Dermatologic disorders are some of the most common conditions affecting exotic companion mammals. This article provides a clinical approach of the conditions presenting with alopecia, pruritus, scaling/crusting, erosion/ulceration, and nodules in order to select and interpret the appropriate diagnostic tests to achieve a diagnosis for a successful treatment.

Zoonotic Dermatoses of Exotic Companion Mammals.

Integumentary disorders caused by zoonotic agents are very common in exotic companion mammals. This article provides an understanding of the main zoonotic dermatoses including parasitic, fungal, bacterial, and viral diseases to provide the most updated information on their epidemiology, diagnosis, reported clinical signs, and therapies.

Acupuncture for Hindlimb Lameness in a Ferret

A geriatric ferret with a complicated medical history (adrenal disease, kidney disease, hindlimb lameness/weakness, chronic diarrhea, urinary incontinence) was presented for traditional Chinese veterinary medicine (TCVM) evaluation. A thorough conventional medical work-up had been performed but financial resources were unavailable for specialty referral. The owner, however, still wanted her pet to have a good quality of life for as long as reasonably possible. The ferret was a good candidate for acupuncture given that TCVM theory explained many of the clinical abnormalities. The owner’s most significant concern was the patient’s mobility and pain; therefore, the TCVM Patterns of Kidney Qi Deficiency and local Qi Stagnation were the focus of the initial TCVM visits. Aside from the deslorelin implant, the owner elected to discontinue all traditional medications. Improvements noted in the patient’s quality of life correlated with the acupuncture therapy received. Over a 2-month period and 5 acupuncture sessions, the patient’s mobility and urinary incontinence improved and complete resolution of the diarrhea occurred. At the conclusion of care for this patient, a recommendation for continuing TCVM was made with acupuncture treatments every 1-2 months along with disease monitoring with conventional diagnostics. This case is an excellent example of the medical benefits of acupuncture in an exotic companion mammal.

Small mammal herbivores part 3: taking a dietary history and providing nutritional support

The unique dietary needs of exotic companion mammal herbivores has been thoroughly explored in this series of articles. The veterinary nurse can be well-equipped and is in an excellent position to take a detailed husbandry and nutritional history, which can help to identify nutritional disease and problems with dietary management that may contribute to future pathogenesis. Providing nutritional support in the hindgut fermenter inpatient or outpatient is centred around both restoring the negative energy balance (as the target species will rapidly enter a catabolic state) and providing enough fibre to stimulate gastrointestinal motility.

Novel food resources and conservation of ecological interactions between the Andean Araucaria and the Austral parakeet.

In fragile ecosystems, the introduction of exotic species could alter some ecological processes. The Austral parakeet (Enicognathus ferrugineous) shows close ecological and evolutionary relationships with the Andean Araucaria (Araucaria araucana), so any alteration in these interactions may have negative consequences for both partners and for ecosystem functioning and structure. We conducted extensive roadside surveys to estimate the abundance of parakeets in the northern Patagonian Andes over 4 years and recorded the food plants consumed by foraging flocks. The use of native habitats and humanized areas like villages and farms was influenced by the Araucaria seed crop. In masting years, the large seed crop allowed a massive use of this resource during the non‐breeding season, and even during the breeding season. The exploitation of exotic plants was minor in the masting year, but became predominant in non‐masting years, especially during the non‐breeding season. This feeding switch towards exotic plants primarily arose because the low Araucaria seed crop in non‐masting years is entirely consumed just after production by domestic and wild exotic mammals living in Araucaria forests year‐round, thus forcing the displacement of parakeets towards anthropic habitats to exploit exotic plants. Given the degradation of the remaining Andean Araucaria forests due to the impact of exotic mammals on the ecological interaction between Araucaria and Austral parakeets, ambitious programs to exclude or reduce the density of these alien mammals, including livestock, are warranted.

Small mammal herbivores part 1: digestive system adaptations to a herbivorous diet

Nutritional disease is common in exotic companion mammals, and the unique dietary adaptations of herbivorous species only compounds this issue. The target species (including lagomorphs, and hystricomorph or caviomorph rodents) exhibit anatomical and physiological adaptations to a plant-based diet that is low in calories and protein, and high in fibre. Digestive tract adaptations such as hypselodont dentition to hindgut fermentation will be reviewed. Veterinary nurses are in an excellent position to counsel pet owners on the appropriate nutrition of their companion animals, and understanding these unique adaptations provides the necessary baseline knowledge to make recommendations.

Endotracheal intubation of small exotic mammals

The veterinary nurse or technician plays an important role in avian and exotic anaesthesia, often inducing, intubating, and maintaining an anaesthetic while the veterinary surgeon prepares for a procedure. Gone are the days of avian and exotic specialists being the only source of veterinary care for companion rodents; with an increase in the ownership of these species comes an increase in general practitioners undertaking routine or preventative health procedures. Owners of these pets expect the same standard of care afforded to dogs and cats, and consequently veterinary staff may be required to provide the same standard of intensive anaesthetic management. Successful anaesthetic management requires an awareness of patient limitations, and one such limitation in small exotic mammals is the difficulty of endotracheal intubation. Intubation allows for better respiratory control while minimising the risk of aspiration and is particularly important for procedures lasting longer than 30 minutes, during which hypoventilation and respiratory obstruction are most likely to occur. Regardless of procedure length or complexity, intubation should be the routine standard of care if it can be done in a swift and safe manner.

Landscape use and food habits of the chilla fox (Lycalopex griseus, Gray) and domestic dog (Canis lupus familiaris) in a peri-urban environment of south-central Chile

Abstract Cities intensely modify natural environments and impose pressures on biodiversity. In this sense, carnivorous mammals are one of the groups most affected due to their food and space requirements. The feeding and spatial behavior of the chilla fox (Lycalopex griseus, G., 1837) and dogs were studied in the vicinity of a peri-urban protected area in south-central Chile. The diet of both canids was compared seasonally, for which feces were collected along trails in three habitats: native forest, exotic plantations and scrublands. Dog feces were collected at the same site to establish whether they were avoided by foxes. Chilla fox has been highlighted for consuming a high proportion of hares followed by rodents of the Muridae family, both being exotic mammals in Chile, whereas dogs showed a predominant consumption of anthropogenic food. Significant differences were observed for chilla fox in dietary diversity, mainly in summer and fall. No spatial segregation was observed with the domestic dog, which was evidenced in a high overlap in the use of all habitats. This scenario, together with continuous human presence, are elements that must be considered in the medium-term to evaluate the effects of anthropogenic pressures on native carnivores in the study area.

Exotic mammals and rewilding in the Neotropics

Exotic mammals and rewilding in the Neotropics

Bloqueio paravertebral lombar em coelho (Oryctolagus cuniculus) submetido à amputação de membro pélvico - relato de caso

ABSTRACT The concern about pain management in exotic mammals is increasing. However, only a few studies describe locoregional anesthesia techniques in rabbits. Thus, this report aims to describe the lumbar paravertebral block, guided by peripheral nerve stimulation, in a rabbit undergoing mid-femoral amputation. We received a one-year-old rabbit weighing 1.27kg with a history of non-union of the right femur and osteomyelitis. The animal came to us for high pelvic limb amputation. After premedication with ketamine, midazolam, and morphine, the patient was maintained under general anesthesia in a non-rebreathing circuit under spontaneous ventilation with isoflurane vaporized in 0.6 oxygen. Using a peripheral nerve stimulator, we performed the lumbar paravertebral block, positioning the needle between the L5 and L6 vertebrae and injecting 0.2mL/kg bupivacaine. The patient remained stable throughout the procedure, without the need for analgesic rescue with opioids during surgery and postoperatively. The discharge occurred after 24 hours. The lumbar paravertebral block proved efficient for trans and postoperative analgesia for high pelvic limbic amputation in rabbits.