Lycalopex Gymnocercus Research Articles

Ixodids in wild animals of the mountainous plateau Region of Santa Catarina State, Brazil

<p class="Pa7"><span lang="EN-US">Knowledge of ixodids (hard ticks), as of well as their ability to transmit pathogens to their hosts, and in some cases to humans, is significantly important for the establishment of epidemiological public health programs and surveillance. With the purpose of identifying ixodids from wild mammals in the mountainous plateau of Santa Catarina, we examined ticks collected or received in the Laboratory of Parasitology and Parasitic Diseases of the Centre of Agroveterinary Sciences (CAV/UDESC) from 2001 to 2011. The ixodids were collected from wild animals that were subjected to the screening process of the Veterinary Clinic Hospital (HCV) of CAV and from dead animals found on state highways. Using specific dichotomous keys, we identified <em>Amblyomma aureolatum </em>collected from <em>Pseudalopex gymnocercus</em>, <em>Lycalopex gymnocercus</em>, <em>Leoparduspardalis</em>, <em>Cerdocyon thous</em>, <em>Leopardus tigrinus</em>, <em>Puma concolor, </em>and <em>Bufo </em>sp.; <em>A. dubitatum </em>collected from <em>Hydrochoerus hydrochoeris</em>; <em>A. rotundatum </em>from <em>Puma concolor </em>and <em>Bohtrops </em>sp.; <em>A. ovale </em>from <em>Bufo </em>sp.; and <em>Rhipicephalus microplus </em>from <em>Mazama gouazoubira</em>. A specimen of <em>A. longirostre </em>was identified in an urban area house at the municipality of Lages. <em>A. rotundatum </em>that was collected from <em>Bohtrops </em>sp. and <em>Puma concolor</em>, and <em>A. longirostre </em>that was found in the environment, are reported for the first time in the state of Santa Catarina, Brazil. </span></p>

Adenoviruses of canine and human origins in stool samples from free-living pampas foxes (Lycalopex gymnocercus) and crab-eating foxes (Cerdocyon thous) in São Francisco de Paula, Rio dos Sinos basin.

The spread of enteric viruses of domestic animals and human beings to wild species can be facilitated by the resistance of these viruses on the environment and their ability to be transmitted by water and contaminated food. The health status of the populations of pampas foxes Lycalopex gymnocercus) and crab-eating foxes (Cerdocyon thous) is largely unknown and the landscapes occupied by these animals in southern Brazil have been threatened by human occupation and expansion of agriculture. In this work, the search of genomes of human and canine adenoviruses in feces from these wild carnivores was used to track the dissemination of domestic animals and human pathogens to the free-living populations in a wildlife reserve located in southern Brazil. This was performed by virus-specific differential real-time polymerase chain reactions (qPCR) on stool specimens, avoiding capture and additional stress to the animals. Genus-specific conventional reverse-transcriptase PCR (RT-PCR) was complementarily performed aiming the detection of enteroviruses (EV) and rotaviruses (RV) on these same samples. HAdV genomes were found on 14 out of the 17 (82.35%) stool samples analysed, whereas CAV was found co-infecting 5 of these samples. RV genomes were detected on 7 of the 17 samples (41.18%) and all samples were negative for EV. The results point to the dispersion of HAdV and RV at a high rate to these species of South American wild carnivores, which can be an effect of growing anthropisation of the habitat of these animals.

Dissimilar responses of the Gray brocket deer (Mazama gouazoubira), Crab-eating fox (Cerdocyon thous) and Pampas fox (Lycalopex gymnocercus) to livestock frequency in subtropical forests of NW Argentina

This study represents the first analysis of livestock influence over individual mammal species in NW Argentina forests. Through camera-trapping, I found a negative correlation between frequencies of occurrence of livestock (sheep, goats and cattle) and Gray brocket deer Mazama gouazoubira, and a modification of the daily activities patterns of the latter according to changes in density of the former. However, no evident associations between Crab-eating fox Cerdocyon thous and Pampas fox Lycalopex gymnocercus frequencies and livestock were found. This study provides insights on the effects of extensive ranching over mammal species in NW forests of Argentina, where this activity is of major importance among forests inhabitants.

Sex determination of three Neotropical canids by high resolution melting analysis

We describe a fast and reliable genetic method for sexing Neotropical canids by high resolution melting analysis of amplicons obtained by real time polymerase chain reaction. We used a primer set that amplifies a 195 bp fragment of the ZFX and ZFY genes to determine the sex of pampas fox (Pseudalopex gymnocercus), crab eating fox (Cerdocyon thous), maned wolf (Chrysocyon brachyurus), and domestic dog (Canis familiaris). This new method is useful, fast and reliable for sexing of noninvasively obtained samples with low DNA quality and quantity. This protocol could be easily modified to sex non-invasive samples of other canid species.

Análisis zooarqueológico del sitio laguna El Doce (Depto. Gral. López, Sta. Fe, Argentina)

The results from taxonomic and taphonomic analyses of the first evidence of archaeofaunal record recovered in systematic excavation carried out at Laguna El Doce archaeological site (Santa Fe province, Argentina), whose chronology covers different moments of the Holocene, are presented in this paper. The bone assemblage includes even-toed ungulates (Lama guanicoe, Ozotoceros bezoarticus), rodents (Rodentia, Ctenomys sp., Lagostomus maximus), armadillos (Chaetophractus villosus, Dasypus hybridus, Tolypeutes matacus, Zaedyus Pichiy, Eutatus seguini), carnivores (Canidae, Pseudalopex gymnocercus) and birds (Bird, Rhea americana). Low stages of weathering, low frequency of rodents, carnivores and roots marks and chemical depositions (MnO2 and CaCO3) characterized the sample. Also show evidence of anthropic modifications such as fractures, thermal alterations and cut mark.

Nefrectomia videolaparoscópica em Graxaim-do-campo (Pseudalopex gymnocercus) com displasia renal

Graxains-do-campo habitam o centro-leste da América do Sul, desde o sudeste do Brasil e leste da Bolívia. A displasia renal compreende um espectro de anomalias e é frequentemente relatada em cães de diversas raças, sendo a maioria dos relatos achados de necropsia. A maior parte das doenças renais congênitas nos cães apresenta caráter progressivo, portanto o tratamento é limitado e direcionado a fim de retardar a progressão da doença renal estabelecida. No presente relato é descrita a realização de nefrectomia laparoscópica em graxaim-do-campo (Pseudalopex gymnocercus) com displasia renal. Suspeitou-se de doença no rim direito por meio de ultrassonografia e urografia excretora. Para o procedimento cirúrgico foram utilizados três portais (10, 10, 5mm), endoscópio rígido de 10mm/0(0) e clipes para hemostasia dos vasos renais. A técnica cirúrgica utilizada neste canídeo selvagem foi semelhante à usada em cão doméstico, devido à escassez de relatos em cirurgias em graxaim e a inexistência de descrições de nefrectomia videolaparoscópica em graxaim-do-campo. O animal foi acompanhado por um período de 30 dias pós-cirurgia sem a ocorrência de complicações. O presente relato demonstra que a técnica proposta foi adequada para a realização de nefrectomia videolaparoscópica em Graxaim-do-campo.

A comparison of heterochromatic regions in three species of neotropical canids

Repetitive DNA varies in nature and abundance, and has had an important role in genome evolution of higher eukaryotes. In the present study we analyzed the dynamics of heterochromatic regions and telomeric sequences in three endemic South American canid species, Chrysocyon brachyurus, Lycalopex gymnocercus, and two subspecies of Cerdocyon thous by means of C-banding and fluorescence in situ hybridization (FISH) with telomeric probes. The three species revealed different banding patterns evidencing amplifications of centromeric heterochromatic and telomeric regions co-localized with telomeric sequences in L. gymnocercus and C. thous, and the presence of a heterochromatic terminal block in the Y chromosome of C. brachyurus. Additionally, an unusual heteromorphism of chromosome pair 1 was observed in the subspecies Cerdocyon thous entrerrianus. Our work emphasizes the importance of cytogenetic studies at the population level comprising the largest possible area of the geographic distribution of the species.

Natural infection of the wild canid, Cerdocyon thous, with the piroplasmid Rangelia vitalii in Brazil

Canine rangeliosis, caused by the piroplasmid protozoon Rangelia vitalii, is currently recognized as a reemerging disease that affects domestic dogs in Brazil. In the present study, piroplasmid infection was searched in wild canids (20 Cerdocyon thous and 4 Lycalopex gymnocercus) in Brazil. Molecular analysis, based on PCR and DNA sequencing of a portion of the 18S rRNA gene, revealed that 30% (6/20) C. thous were infected by R. vitalii. Blood and bone marrow samples from one of the R. vitalii-infected C. thous were inoculated into a domestic dog, which developed clinical rangeliosis that was confirmed by molecular tests. However, the C. thous donor showed no clinical, hematological or biochemical alterations, even though its R. vitalii infection status was confirmed for at least 80 days. These observations suggest that R. vitalii is not as highly pathogenic for C. thous as it is for domestic dogs. Phylogenetic analysis inferred by the 18S rRNA gene placed R. vitalii embedded in the clade ‘Babesia sensu stricto’, consisting of a number of species that represent truly the genus Babesia. It is proposed that the species R. vitalii should be transferred to the genus Babesia. The present study expands our knowledge on the natural history of R. vitalii, suggesting that it might have a natural cycle involving the wild canid C. thous. Further studies are needed to confirm that C. thous is a natural reservoir of R. vitalii in Brazil.

The Pampas fox (Lycalopex gymnocercus) as new definitive host for Spirometra erinacei (Cestoda: Diphyllobothriidae)

Spirometra erinacei, Faust, Campbell and Kellogg, 1929, is a pseudophyllidean cestode of the family Diphyllobothriidae. The genus Spirometra is cosmopolitan and these parasites infect carnivores, specially felids and canids. In Argentina, S. erinacei and S. mansonoides have been reported sporadically only in domestic definitive hosts. The Pampas fox, Lycalopex gymnocercus, is the most abundant native carnivore in southern South America, where it inhabits grasslands and open woodlands and areas highly modified by extensive ranching and agricultural activities. This report describes the first finding of S. erinacei infecting Pampas fox, and provides an estimate prevalence of this cestode in rural areas of southern Buenos Aires province, Argentina based on 78 complete Pampas fox intestine samples analysis. This study found a 15.4% of prevalence of S. erinacei in small intestine (adult stage) and a 21.8% in fecal samples (egg stage). In the present work, the first case of S. erinacei in a wild definitive host from Argentina was reported expanding the list of definitive hosts of S. erinacei in South America.

Systematic Revision of “Canis” Ensenadensis Ameghino, 1888 (Carnivora, Canidae) and the Description of a New Specimen from the Pleistocene of Argentina

The fossil record of foxes in South America is very rich, with almost all extant South American species recorded. Currently, three fossil species are known in the Plio-Pleistocene of South America: “Dusicyon” cultridens, Dusicyon avus and “Canis” ensenadensis. In the present work we reviewed the systematics of “Canis” ensenadensis from the Pleistocene of Buenos Aires province using both qualitative and quantitative approaches. We also described a new fossil specimen (MCA 2082) from Buenos Aires Province (Argentina) that shares some similarities with “Canis” ensenadensis. We compared the fossil specimens with a large sample of specimens that includes the living species Lycalopex gymnocercus, L. culpaeus, Cerdocyon thous, L. fulvipes, L. vetulus, L. sechurae and Atelocynus microtis. We performed a Principal Component Analysis using mandibular and dental measurements, and then a geometric morphometric analysis using photographs of the lateral view of the mandible. Our results indicate that “Canis” ensenadensis is a valid species and it should be included in the genus Lycalopex. We also conclude that MCA 2082 is a member of the genus Lycalopex, probably belonging to the species L. ensenadensis. These results suggest that the biochron of L. ensenadensis reaches the Lujanian Age. Even if our assignation of MCA 2082 is incorrect, this specimen represents a different taxon from those already described for the Lujanian, thus the diversity of foxes during the Lujanian is greater than previously known.

Chemical immobilisation of free-ranging Pampas foxes (Pseudalopex gymnocercus): Assessment of ketamine–xylazine and tiletamine–zolazepam combinations

Two protocols to immobilise free-ranging Pampas foxes for ear-tagging or radio-collaring were evaluated. One hundred fifteen foxes were injected with ketamine–xylazine (K–X) and thirteen with tiletamine–zolazepam (T–Z). The use of both T–Z and K–X combinations typically resulted in a smooth induction and recovery. In 86% of the cases K–X protocol was judged effective (mean±SD, K: 10.7±3.3mg/kg, X: 1.0±1.0mg/kg) while T–Z protocol was judged effective in 92% of the cases (T: 3.6±1.05mg/kg, Z: 3.6±1.05mg/kg). The primary differences between the two drug combinations were that the time necessary for the complete recovery was longer with T–Z, and thermic problems were found more frequently with K–X. Additionally, our results suggest that thermic stress may be a relatively frequent complication for Pampas foxes. This study provides baseline data on some physiologic variables in Pampas foxes captured with different methods and drugs in field conditions.

Molecular identification of a Fuegian dog belonging to the Fagnano Regional Museum ethnographic collection, Tierra del Fuego

Native-European contact in Tierra del Fuego was a rapid process, for which little ethnographic information has been produced. Although the Fuegian dog seemed to have been important to Selk'nam people's life, the taxonomic status of this extinct animal is still uncertain. The aim of the present work was to determine the zoological identity of a taxidermized canid belonging to a Fagnano Regional Museum collection, Río Grande, Tierra del Fuego. For this purpose, DNA from Fuegian dog and patagonian wild canids (Lycalopex culpaeus, Lycalopex griseus and Lycalopex gymnocercus) hairs was extracted. An mtDNA Region Control fragment was amplified by PCR and sequenced. Sequence alignment was performed among the sequences that were obtained in this research and the Canis lupus familiaris sequence from GenBank. Pairwise analysis showed a higher identity between the Fuegian dog and the culpeo fox (97.57%), with greater divergence with the current domestic dog (88.93%). These results were supported by the molecular phylogenetic analysis, suggesting atypical fox domestication by hunter-gatherers.

Epidemiological studies on Echinococcus in Pampas fox (Lycalopex gymnocercus) and European hare (Lepus europaeus) in Buenos Aires province, Argentina

In Argentina, hydatid disease caused by Echinococcus granulosus is widespread. The south of Buenos Aires province, Argentina, is one of the three regions where hydatidosis is endemic. Although domestic dogs and sheep are considered to be the main hosts for E. granulosus, the potential role of wildlife in the local transmission of E. granulosus has not been investigated. The aim of this study was to estimate the hydatidosis/echinococcosis prevalence in European hare (Lepus europaeus) and Pampas fox (Lycalopex gymnocercus), two abundant species with a strong predator-prey relationship in rural areas of Buenos Aires province using different diagnostic tests. A total of 61 fox intestines were examined, finding that 52 (85.2%) harbored at least one helminth species. However, no adult or immature form of Echinococcus sp. was found in the intestinal contents. Coproparasitological analysis and Copro-ELISA followed by Copro-PCR were used as supplementary diagnostic tests. Only one (1.7%) of 59 fecal samples was positive to Taeniidae eggs by coproparasitological analysis, but this same sample was negative by the Copro-ELISA test. The analysis by Copro-ELISA showed 6 of 57 (10.6%) positive samples, but the Copro-PCR tests carried out on these samples were negative to E. granulosus. A total of 6,808 lungs, 3,576 livers, and 3,542 hearts of hunted hares were examined and palpated, but no structure resembling hydatid cysts were detected. Our results suggest that hares and Pampas foxes are not currently important wild reservoirs of E. granulosus in the studied area.

Abundance of Conepatus chinga (Carnivora, Mephitidae) and other medium-sized mammals in grasslands of southern Brazil

Between January 2007 and December 2010, the abundance of medium-sized mammals was studied, with special focus on the Molina's hog-nosed skunk, Conepatus chinga (Molina, 1782), at four locations in southern Brazil. In this study, transect line methodology was used to obtain data for Distance Analyses. Transects were traveled by car at night, searching with spotlights along the edges of secondary roads in agricultural landscapes. Along 1,811 km, we obtained 620 observations of 20 mammal species. The most common species was the exotic European hare, Lepus europaeus (Pallas, 1778); the highest abundance estimated for South America was observed in one of the study areas, where its density was estimated as 32 individuals/km². Carnivores were the most commonly recorded mammals, represented by 10 species and comprising 51% of all observations. Molina's hog-nosed skunk occurred in all study areas, but occurred in sufficient numbers to obtain density estimates in only two of the areas. We estimated 1.4 to 3.8 individuals/km², in the first density estimate made by the transect method for a member of Conepatus in the Neotropics. These values are similar to those estimated for North American species of Mephitidae. In Brazil, C. chinga is apparently more abundant in the Pampa biome than in the grasslands of the Atlantic Forest. For two other carnivores, Lycalopex gymnocercus (Fisher, 1814) and Cerdocyon thous (Linnaeus, 1766), we estimated preliminary densities that were similar to those previously cited for different regions.

Spatial organization of the Pampas fox in a grassland relict of central Argentina: a flexible system

AbstractThe Pampas fox (Pseudalopex gymnocercus) is a generalist South American canid that adapts well to the human‐dominated landscape of the Argentine pampas, which is largely converted to agriculture and pastures. However, little is known about its ranging behaviour and spatial organization in relict native grasslands. We captured and tracked 13 radio‐tagged adult foxes between December 1998 and June 2005 in Ernesto Tornquist Provincial Park, a protected area with a dense population of wild horses, an important food item for foxes. The home range of 10 adult males averaged 1.40 ± 0.96 km2 (mean ± sd; 95% minimum convex polygon, MCP) and was not significantly larger than that of three adult females, 1.20 ± 1.07 km2 (95% MCP). Evidence of individual's site fidelity over the study period is indicative of locally abundant food resources all year round. It is likely that the availability of horse carcasses is a main driver of the spatial organization of Pampas foxes in this population. Our population density estimate of 1.1–1.5 foxes per km2 falls within the know range of population densities for Pampas foxes, and was close to the upper limit, as also expected from an abundant and aggregated food resource such as horse carrion. Reduced hunting pressures, however, may also contribute to explain the relatively high population densities of foxes in this protected area.

Infection with a Hepatozoon sp. closely related to Hepatozoon felis in a wild Pampas gray fox (Lycalopex –Pseudalopex –gymnocercus) co-infected with canine distemper virus

A species of Hepatozoon closely related to Hepatozoon felis found in the skeletal and cardiac muscle of a wild Pampas gray fox (Lycalopex gymnocercus) is described. The fox was euthanized after showing severe incoordination. On necropsy and histopathology there was bilateral, diffuse, severe, sub-acute, necrotizing bronchointerstitial pneumonia, with intracytoplasmic and intranuclear eosinophilic inclusion bodies. Canine distemper virus was detected by immunohistochemistry in the bronchiolar epithelium, syncytial cells, alveolar macrophages and pneumocytes. The skeletal muscle and myocardium contained multiple round to oval protozoan cysts ranging from 64μm×75μm to 98μm×122μm, with a central eosinophilic meront-like core surrounded by concentric rings of mucinous material resembling Hepatozoon americanum cysts but smaller in size. Macrophages within rare pyogranulomas and monocytes/macrophages in adjacent sinusoidal blood vessels in the skeletal muscle contained intracytoplasmic round protozoa consistent with merozoites or developing gamonts of Hepatozoon. Hepatozoon sp. infection was confirmed by PCR of skeletal muscle and the sequenced 18S rRNA PCR product was found to be 99% identical to H. felis by BLAST analysis and deposited in GenBank as accession number HQ020489. It clustered together in the phylogenetic analysis with published H. felis sequences and separately from H. canis, H. americanum and other Hepatozoon species. However, the close relatedness of the fox Hepatozoon to H. felis does not rule out infection with a different and possibly unknown Hepatozoon species.

Learning interspecific communicative responses in Pampas foxes (Lycalopex gymnocercus)

Domestic dogs show remarkable communicative abilities in their interaction with people. These skills maybe explained by the interaction between the domestication process and learning experiences during ontogeny. Studies carried out on other species of canids, which have not been domesticated are relevant to this topic. The purpose of this article is to study the effect of instrumental learning on captive Pampas foxes' (Lycalopex gymnocercus) communicative responses to humans. Seven foxes were tested in a conflict situation involving food within sight but out of their reach. In these situations dogs typically gaze at the human face to ask for food. In Study 1, there was an increase in gaze duration as a consequence of reinforcement and a decrease during extinction, when animals did not receive any more food. In Study 2, all of the four foxes tested successfully followed proximal pointing gesture to find hidden food. When a distal pointing cue was given, three out of four followed it in the first session and one in the second session. These results are consistent with those previously found in dogs, and suggest that learning experiences allow the development of communicative skills, even in not domesticated canid species.

Diet of Adults and Cubs ofLycalopex gymnocercusin Pampas Grassland: A Validation of the Optimal Foraging Theory?

We compared the diet of adult Pampas foxes (Lycalopex gymnocercus) and their cubs in a Pampas grassland area of Argentina by analysing 152 scats (adults: 92, cubs: 60). We used an Index of Relative Importance (IRI) to determine the contribution of prey items to the diet. IRI scores for rodents, hares and birds were higher for cubs, whereas adults consumed grasshoppers and larvae more often than cubs did. Fruits and carrion of ungulates were consumed only by adults. Both the number of items per scat and diet diversity were smaller for cubs than adults. We conclude that the Pampas fox behaves as a typical central place forager, with fruits and insects being probably consumed on the spot (with low foraging costs) and rodents, birds and hares being brought to the den for the cubs.

Exposure of pampas fox (Pseudalopex gymnocercus) and crab-eating fox (Cerdocyon thous) from the Southern region of Brazil to Canine distemper virus (CDV), Canine parvovirus (CPV) and Canine coronavirus (CCoV)

The exposure of 13 Brazilian free-ranging nondomestic canids (five pampas fox - Pseudalopex gymnocercus and eight crab-eating fox -Cerdocyon thous) from Southern region of Brazil, to Canine distemper virus (CDV), canine parvovirus (CPV) and Canine coronavirus (CCoV) was investigated. Antibodies against CDV were detected in 38.5% (5/13) of the samples. There were anti-CDV antibodies in 60% (3/5) of P. gymnocercus and in 25% (2/8) of C. thous. The frequency was higher among the adults and males. Eleven canids (84.6%) presented antibodies against CPV, 80% (4/5) were from P. gymnocercus and 87.5% (7/8) were from C. thous. There was no difference in positivity rate against CPV between gender and age. Antibodies against CCoV were detected in 38.5% (5/13) of the samples, with 60% (3/5) of positivity in P. gymnocercus and 25% (2/8) in C. thous. The frequency of antibodies against CCoV was higher among the adults and males. The study showed that these canids were exposed to CDV, CPV and CCoV.

Trichinella infection in wild animals from endemic regions of Argentina

Natural infection with Trichinella has been described in more than 150 mammalian species. However, few reports of Trichinella infection in wild animals have come from Argentina. In this study, muscle tissue was obtained from wild animals in Argentina with the aim of evaluating the presence of Trichinella. A total of 169 muscle samples were collected to determine the presence of Trichinella larvae by artificial digestion. The 169 muscle samples originated from 12 species including 36 opossums (Didelphis albiventris), 19 armadillos (Chaetophractus villosus), 9 capybaras (Hydrocaeris hydrocaeris), 1 puma (Puma concolor), 3 grey fox (Lycalopex gymnocercus), 6 coypus (Myocastor coypus), 6 skunks (Conepatus chinga), 2 ferrets (Galictis cuja), 66 rats (Rattus norvegicus), 6 mice (Mus musculus), 12 wild boars (Sus scrofa), and 3 wild cats (Felis geoffroyi). Trichinella infection was detected in 1 puma [2 larvae per gram (LPG)], 3 wild boars (8-420 LPG), 3 armadillos (0.04-0.08 LPG), and 9 rats (0.1 to 150 LPG). Only 3 Trichinella isolates, of 1 rat and 2 wild boars from Neuquén, were identified as Trichinella spiralis by nested PCR. The presence of Trichinella infection among wild animal populations suggests a sylvatic cycle of transmission in Argentina, which can serve as a reservoir for humans and domestic animals. Further, evidence of high prevalence in rats emphasizes the need to improve pig management, mainly in small individual farms without adequate technology, to enhance the quality of feeds, and to improve veterinary services to avoid exposure of pigs to Trichinella.