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Behavior, Nutrition, and Veterinary Care of Patagonian Cavies (Dolichotis patagonum)
Abstract
Patagonian cavies (Dolichotis patagonum) are large South American rodents well adapted for cursorial life (well adapted for running). They are monogamous but can live in groups of up to 70 individuals who maintain communal burrows. They are primarily herbivorous and may be maintained on commercially produced rodent or primate diets. Their long, thin legs and skittish nature make them difficult to restrain. Common medical problems include malocclusion of cheek teeth, gastrointestinal parasites, hypertrophic cardiomyopathy, and traumatic leg fractures.
... However, in contrast to these species it is highly cursorial, occupying a niche in the Patagonian steppe resembling small antelopes or gazelles in the African savanna and Argentina. Maras weigh between 7 and 9 kg and have an external length of approximately 610-810 mm [2]. They are distinguished mainly by their long ears and longer limbs compared to other cavies. ...
... Maras are diurnal herbivorous hindgut fermenters who consume a variety of plants species, with a particular focus on grasses [4]. Due to their hardiness in temperate climates, maras are often displayed as semi -free -ranging animals in zoological gardens, where they can roam pastures freely or be kept in large pasture enclosures [2]. Recently, maras have become one of the popular pets for exotic animal lovers, while in the past they were not recommended to keep as pets because of their gazelle -like, nervous character [2]. ...
... Due to their hardiness in temperate climates, maras are often displayed as semi -free -ranging animals in zoological gardens, where they can roam pastures freely or be kept in large pasture enclosures [2]. Recently, maras have become one of the popular pets for exotic animal lovers, while in the past they were not recommended to keep as pets because of their gazelle -like, nervous character [2]. In general, maras are healthy animals and easy to raise. ...
Background
Anticoagulant rodenticide (AR) poisoning was diagnosed in 3 Patagonian maras (Dolichotis patagonum) raised in the mara farm in Thailand. To date, there have been no reports of maras with diagnosed AR poisoning.
Case presentation
The first clinical sign of the sickening maras was anorexia. Fifteen from 50 maras were dead over a 3–5 day period after the clinical signs had occurred. Positive results to AR were detected in all of the maras’ liver specimens by screening test using thin layer chromatography and spectrophotometry methods. Supportive therapy was selected for the treatment of the 35 surviving maras. During the follow – up observation period of 12 months, all of the surviving maras were healthy and no reproductive loss.
Conclusions
This is the first report on suspected AR poisoning in maras in Thailand based on history taking, clinical signs, gross pathology lesions and chemical analysis. AR poisoning in the present report is possibly from contaminated animal food. Therefore, quality control of food should be fastidious when feeding maras.
... Diseases previously reported in maras include gastrointestinal parasitism, ectoparasitism, histoplasmosis, hypertrophic cardiomyopathy, Besnoitia infections, pododermatitis, cowpox virus, and toxoplasmosis. 14,20 A single study introducing a novel PCR approach to detect and differentiate Leptospira identified L. interrogans in one deceased Patagonian mara; however, the clinical course of disease was not described. 9 Here, the authors describe the course of disease, diagnostics, and treatment in three zoo-housed maras affected by clinical leptospirosis. ...
Rodents are typically viewed as asymptomatic reservoirs for leptospirosis infection, as clinical disease in rodents is rarely described. This report includes three separate cases of leptospirosis in Patagonian maras (Dolichotis patagonum) over a 3-yr period in multiple locations within a single zoo. All three cases presented with varying clinical signs including lethargy, conjunctival hyperemia, hyperbilirubinemia, and presumed renal azotemia. Infection with Leptospira spp. was diagnosed antemortem by PCR on whole blood (n = 1, Case 1) or urine (n = 2, Cases 2 and 3). Leptospira antibody titers measured by serum microagglutination testing (n = 3) were elevated or increased in all three animals over a 1-3-wk period for Leptospira serovars Bratislava and Hardjo (Case 1) and Grippotyphosa (Case 2 and 3). Two of the three animals responded to treatment with penicillin and doxycycline and supportive care, whereas one animal did not respond to treatment. Postmortem findings in this individual included conjunctivitis, chemosis, dehydration, icterus, tricavitary serosanguinous effusions, necrotizing hepatitis, diffuse pulmonary congestion, and edema. Immunohistochemical examination identified scattered Leptospira organisms within hepatocytes and renal tubular epithelial cells. A wild raccoon (Procyon lotor) at the institution tested positive by PCR on kidney tissue for the same Leptospira spp. serovar and was the suspected source of infection. This case series highlights the clinical importance of leptospirosis as a differential for Patagonian maras presenting with lethargy, ocular signs, acute hepatic disease, and azotemia.
... All offspring were born at the institution shortly after dams were acquired from a private breeder 3 yr prior. The habitat consisted of a holding area (approximately 6 3 9 m 2 ) including an open yard with partial shade covering, access to an indoor barn with sand substrate, and a guest-viewing yard (approximately 19 23 All individuals were examined within 2 yr of presentation, and none had a significant medical history. Pest management in the area targeted raccoons and rats; there was a perimeter hotwire and rodent bait boxes with difethialone (Protecta sidekick, Bell Laboratories, Windsor, WI 53598, USA) outside the enclosure. ...
Four of seven Patagonian maras (Dolichotis patagonum) at a zoological institution developed acute neurologic signs that progressed to tetraparesis and death. All affected were young adult females (10 mon-5 yr old) that presented over 11 d. Clinical signs were rapidly progressive and unresponsive to supportive therapies. Two of the four individuals were found deceased 4 d after hospitalization. Two individuals were euthanized due to poor prognosis and decline after 6 and 8 d, respectively. Simultaneously, an additional mara developed mild and self-resolving clinical signs, including a kyphotic gait and paraparesis. On gross examination, there were widespread petechiae and ecchymoses of the skeletal muscle, myocardium, skin, pericardium, urinary bladder mucosa, and spinal cord. On histopathology, all animals had necrotizing myelitis and rhombencephalitis, with intranuclear viral inclusions in three individuals. Electron microscopy confirmed herpesviral replication and assembly complexes in neurons and oligodendrocytes. Consensus PCR performed on spinal cord, brainstem, or cerebellum revealed a novel Simplexvirus most closely related to Simplexvirus leporidalpha 4. The virus was amplified and sequenced and is referred to as Simplexvirus dolichotinealpha1. It is unknown whether this virus is endemic in Patagonian mara or whether it represents an aberrant host species. Clinicians should be aware of this virus and its potential to cause severe, rapidly progressive, life-threatening disease in this species.
... This observation may be attributed to the unique mating system and social structure of this species. Unlike most mammals, Patagonian maras are monogamous, forming strong, lifelong pair bonds (Kessler et al. 2009). The male follows and guards the female wherever she goes, marking her as his territory by urinating directly on her. ...
Chemical senses, including olfaction, pheromones, and taste, are crucial for the survival of most animals. There has long been a debate about whether different types of senses might influence each other. For instance, primates with a strong sense of vision are thought to have weakened olfactory abilities, although the oversimplified trade-off theory is now being questioned. It is uncertain whether such interactions between different chemical senses occur during evolution. To address this question, we examined four receptor gene families related to olfaction, pheromones, and taste: olfactory receptor (OR), vomeronasal receptor type 1 and type 2 (V1R and V2R), and bitter taste receptor (T2R) genes in Hystricomorpha, which is morphologically and ecologically the most diverse group of rodents. We also sequenced and assembled the genome of the grasscutter, Thryonomys swinderianus. By examining 16 available genome assemblies alongside the grasscutter genome, we identified orthologous gene groups among hystricomorph rodents for these gene families to separate the gene gain and loss events in each phylogenetic branch of the Hystricomorpha evolutionary tree. Our analysis revealed that the expansion or contraction of the four gene families occurred synchronously, indicating that when one chemical sense develops or deteriorates, the others follow suit. The results also showed that V1R/V2R genes underwent the fastest evolution, followed by OR genes, and T2R genes were the most evolutionarily stable. This variation likely reflects the difference in ligands of V1R/V2Rs, ORs, and T2Rs: species-specific pheromones, environment-based scents, and toxic substances common to many animals, respectively.
... Maras easily adapt to artificial environments and are able to maintain productivity similar to that of their wild counterparts, as evidenced by different groups living at captive facilities (Campos et al., 2001;Gatica et al., 2019;Kessler et al., 2009;Alonso Rold an et al., 2019). This adaptability is not exclusive to captivity; in the wild, maras also show flexibility in response, for example, to food supply, group-living variations (communal breeding versus breeding alone) (Gatica et al., 2019), and changes in group size (Taber & Mac Donald, 1992). ...
Keywords: behavioural adjustment Dolichotis patagonum mate switching pair bonding partner loss rodent synchronization Maras, Dolichotis patagonum, combine social monogamy and plural breeding, an unusual mating system for mammals. We tested how maras adapt to the forced separation of pair-bonded partners and how the potential new mates perform over the breeding season and during the process of forming new pairs. Fourteen established pairs from a captive population were randomly assigned to a control (C-group; N ¼ 7) or an experimental (E-group; N ¼ 7) condition. The experiment consisted of replacing seven paired males with seven socially unfamiliar males (new potential mates). Individual behaviour and social interactions were recorded over a 6-month period (springesummer; i.e. 14 sessions) from 0800 to 1800 hours, totalling 11 hourly sampling points per session. We measured pair behaviours and degree of general behavioural synchrony over sessions 1e7 (early) and over sessions 8e14 (late). We also measured how social disruption affected the social networking of individuals forming new pair bonds as compared to individuals with established mates. We furthermore assessed the level of activity of females exposed to mate switching and the production of offspring over the breeding season. In the E-group, maras showed a reduction in pair behaviours and synchronization of activities. There were also multiple interactions among females with several males, revealing initial mate choice activity during the early time period. The period of mate choice was characterized by instability in social networking and changes in the strength of a pair's fidelity. Although the E-group included five newly established pairs, offspring production was similar to that of the C-group. Our findings show that after presumably stressful experimental social disruption, most maras repaired in captivity, although with some delay in offspring production, suggesting that this species has the plasticity to cope with male partner loss under semi-controlled environmental conditions. However, the strength of monogamous bonds was affected by this social disruption.
... An adult cavy is 61-81 cm in length and can weigh between 7 and 16 kg. 1,2 They are proportionally more hare-like than guinea pig-like, with long ears and long, thin limbs. The thoracic limb nails are claw-like with the pelvic limbs more hoof-like. ...
A 7.5‐year‐old, 5.6 kg female Patagonian cavy (Dolichotis patagonum) in thin body condition presented for bilateral pelvic limb paresis. Lumbar intervertebral disk extrusion was diagnosed using MRI and neurological examination. Emergency hemilaminectomy was done on the same day of diagnostics. The cavy was premedicated with intravenous (IV) midazolam (0.3 mg/kg) and ketamine (5 mg/kg) followed by alphaxalone (to effect) for induction and tracheal intubation. Anaesthesia was maintained with isoflurane‐in‐oxygen and an IV constant rate infusion (CRI) of ketamine and lidocaine (both 0.3 mg/kg/h) and morphine (0.1 mg/kg, once). The CRI continued for 24 h followed by once daily intravenous buprenorphine (0.03 mg/kg) and subcutaneous meloxicam (0.5 mg/kg). Recovery was calm. The cavy returned to its preoperative behaviour within hours and began eating soon after anaesthesia. Subjectively, the analgesic plan was successful in mitigating post‐operative pathological pain. This case report discusses the perianaesthetic management for spinal surgery in a cavy.
... The monograph on zoo animal management of Hosey et al. (2013) contains, in the behaviour section, a photograph of a mara in a position suggestive of corpophagy. Kessler et al. (2009) conclude that it is still unclear whether maras typically practice coprophagy or not. ...
... For porcupines (Hystrix spp.), limited evidence for sternal recumbency being the typical resting posture exists in a drawing from Felicioli et al. (1997), and in the fact that juveniles are nursed from axillary nipples the mother presents in a sitting position (Tohmé and Tohmé 1980), and it appears intuitive to assume that the presence of spines make this resting posture the most likely one. The mara (Dolichotis patagonum), in spite of its comparatively long limbs, did not use lateral recumbency in the present study (Supplementary Data SD1, Table S2) and used it only to a small proportion in the pilot study (Fig. 5); resting animals in a photograph in Kessler et al. (2009) lie in sternal recumbency or sit, and in a study on the species' behavioral ecology, Taber (1987) described the lying of maras as "sphynx posture." Thus, the hystricomorph rodents investigated appear limited in their resting behavior to a posture that keeps the relation to the gravity vector constant. ...
For ruminants and arboreal herbivores (sloths and colobine monkeys), an influence of digestive physiology on resting postures has been postulated that is linked to the interplay of digestive anatomy and the gravity vector. To further explore this putative relationship, we observed 253 individual terrestrial mammalian herbivores at zoological gardens, noting 29,478 resting events in 36 species during the day and 7,383 resting events of 18 species at night, providing a catalogue of mammalian resting postures. We confirm the constraint of ruminants to sternal recumbency and expand this observation to camelids, which rely on a similar sorting mechanism in their forestomach for rumination, but which use lateral recumbency to a slight but distinctively larger proportion. Generally, larger herbivores rest more in a standing position, and use lateral recumbency more when lying. The use of lateral recumbency in large hindgut fermenters (perissodactyls, elephants) and nonruminant foregut fermenters (macropods, hippos) corresponds to the concept that there is no interplay between gravity and digestive physiology in these species. By contrast, peccaries, hyraxes, and hystricomorph rodents never used lateral recumbency. While this may be related to body size, body shape, or other species-specific characteristics, it also suggests that the interplay of gravity and digestive processes, in particular with the colonic separation mechanism in hystricomorph rodents, should be further investigated.
... Maras, also known as Patagonian cavies (Dolichotis patagonum), are small mammals belonging to the family Caviidae of the order Rodentia [6]. Maras are housed in captivity in zoos worldwide and are native only to Argentina. ...
Among 16 maras housed as a colony at a zoo, 2 initially showed generalized
dermal lesions on the legs, head and abdomen. Approximately 1 month later, following
completion of therapy with amitraz, 6 maras in the same colony, including the 2 previously
diseased animals, showed dermal lesions with severe alopecia and crusting. Sarcoptic mange
was diagnosed on skin scrapings on the basis of morphological criteria. The mites were
highly mobile and abundant in all cases, and no other causative agents were detected.
Colony-wide treatment with ivermectin and prednisolone was administered weekly for a total
of 4 treatments. After therapy was completed in all cohabitants, follow-up scrapings were
negative for Sarcoptes scabiei. This report describes the first known
outbreak of sarcoptic mange in captive maras and successful treatment with acaricides.
Liver lobe torsion has been reported in many species, with frequent reports in rabbits. Here we describe caudate liver lobe torsion and concurrent necrohemorrhagic typhlocolitis in a Patagonian mara (syn: Patagonian cavy, Patagonian hare, Dolichotis patagonum). Following acute death, postmortem examination findings included torsion of the hepatic caudate process, which had fibrous adhesions to the pancreas indicating chronicity. The cecal apex and proximal 30 cm of colon had regionally reddened serosa and diffusely roughened and reddened mucosa with brown-red and granular luminal contents. Key histologic findings included massive necrosis of the torsed hepatic caudate lobe, consistent with infarction, necrotizing hepatitis in remaining areas of liver, necrohemorrhagic typhlocolitis, adrenocortical necrosis and hemorrhage, and renal tubular degeneration and necrosis with tubular casts. Bacterial culture of cecal contents yielded pure growth of Salmonella spp. Death was attributed to toxemia or bacteremia resulting from Salmonella spp. infection, as the hepatic lobe torsion appeared chronic. It was undetermined if the liver lobe torsion predisposed to gastrointestinal compromise and infection. Patagonian maras have some anatomical similarities to rabbits and are highly cursorial, not dissimilar to hares, Lepus spp. We speculate that these characteristics may increase the likelihood of hepatic caudate lobe torsion in this species.
We report the case of a 1‐year‐old, male, entire Patagonian mara ( Dolichotis patagonum ) presented unable to walk as a result of a traumatic comminuted vertebral fracture/luxation and successfully treated with surgical stabilisation using pins and polymethyl methacrylate. The diagnosis was based on neurological examination and computed tomography. The surgery was performed the same day of presentation and the patient recovered well after surgery, eating, urinating and defecating within the next 24 hours. In this paper, we discuss the anaesthetic and peri‐anaesthetic management as well as the postoperative medical considerations, focusing on important anatomical aspects of the species and the surgical procedure that has not been described in maras before.
The keeping of non-traditional or 'exotic' pets has been growing in popularity worldwide. In addition to the typical welfare challenges of keeping more traditional pet species like dogs and cats, ensuring the welfare of non-traditional pets is complicated by factors such as lack of knowledge, difficulties meeting requirements in the home and where and how animals are obtained. This paper uses examples of different species to highlight three major welfare concerns: ensuring that pets under our care i) function well biologically, ii) are free from negative psychological states and able to experience normal pleasures, and iii) lead reasonably natural lives. The keeping of non-traditional pets also raises ethical concerns about whether the animal poses any danger to others (e.g. transmission of zoonotic diseases) and whether the animal might cause environmental damage (e.g. invading non-native habitats when released). The authors used these considerations to create a checklist, which identifies and organises the various concerns that may arise over keeping non-traditional species as pets. An inability to address these concerns raises questions about how to mitigate them or even whether or not certain species should be kept as pets at all. Thus, the authors propose five categories, which range from relatively unproblematic pet species to species whose keeping poses unacceptable risks to the animals, to humans, or to the environment. This approach to the evaluation and categorisation of species could provide a constructive basis for advocacy and regulatory actions.
The mara (Dolichotis patagonum) is a species classified as "Near Threatened" by the International Union for Conservation of Nature. In the wild, it inhabits only Argentina, but it is also kept in zoos around the world. In order to investigate the endoparasites of the maras kept in the Attica Zoological Park, Greece, four fecal examinations were performed in a period of 4 yr (2008-2011) by standard parasitologic methods. Cysts of the protozoan parasite Giardia spp. and eggs of the nematode Trichuris spp. were found in all four examinations. The possible routes of infection of the maras and the importance of these parasites to other animals and to humans are discussed.
The diet of mara (Dolichotis patagonum, Zimmeraman 1780) within the limits of Sierra de las Quijadas National Park (San Luis, Argentina) is described. Other studies regarding mara's diet showed that mara, feeds on different species of grasses and shrubs. However, there is controversy regarding the proportions of these items in the diet or whether this proportion varies seasonally. Considering mara's body size, anatomical features and physiology, we suggest that mara feeds on grasses in a greater proportion than shrubs and forbs. Moreover, giving that in this region precipitation varies considerably between seasons; it is also expected to find a correlation between the diet of mara and seasons. Fecal pellets of mara were collected during four periods including two dry, and two wet seasons. Relative frequency of each item in scats was determined by microhistological analysis. Results support the hypothesis that mara shows preference for grasses, despite they are less available than shrubs and forbs and that this preference remains constant through seasons regardless of the precipitation regime. The characteristics of mara's diet and the ecological implications of these findings are discussed.
In the semiarid Monte desert, Río Negro province, the mara (Dolichotis patagonum) and the European hare (Lepus europaeus), which was introduced about hundred years ago, today occur sympatrically, as in many regions of Argentina. The forage use of these herbivores was determined by fecal analysis in order to estimate food partitioning and the presumed interspecific nutritional competition. Microhistological analysis of the fecal plant remnants collected at three study sites proved a high overall similarity in diet for both species, primarily based on shrub consumption during summer and winter. However, annual and perennial grasses and forbs were also foraged, especially in spring. Though a trophic niche overlap of about 50% was calculated, it remains doubtful if the introduced hare has diminished the mara population.
Theoretical models of species coexistence between desert mammals have generally been based on a combination of food and microhabitat selection by granivorous rodents. Although these models are applicable in various deserts of the world, they cannot explain resource use by mammals in Neotropical deserts. The present study examines diet composition in a mammal assemblage in the Monte desert, Argentina. The results show that two main strategies are used by these mammals: medium-sized species (hystricognath rodents: Dolichotis patagonum, Lagostomus maximus, Microcavia australis and Galea musteloides; and an exotic lagomorph: Lepus europaeus) are herbivores, whereas small-sized species (a marsupial: Thylamys pusillus; and sigmodontine rodents: Graomys griseoflavus, Akodon molinae, Calomys musculinus, Eligmodontia typus) are omnivorous. Small mammals also show a tendency towards granivory (C. musculinus), insectivory (A. molinae and T. pusillus) and folivory (G. griseoflavus).
Although maras (Dolichotis patagonum) are among the most representative mammals of South America, knowledge on the ecological processes affecting their conservation is scarce. In particular, the study of habitat requirements and its relationship with breeding success is necessary to identify possible threats and develop conservation action for this endemic mammal. I investigated habitat selection patterns by maras and their relationship with breeding success in Península Valdés, Argentine Patagonia. Maras bred from mid-August to late December, and they tended to build the breeding warrens in open, grass-dominated habitats more than expected while avoided closed habitats dominated by taller shrubs. Mean number of breeding adults per warren was 4.26, while mean number of pups born per warren was 4.46. Overall, 30 (45%) of 67 pups survived until the 6th week of life, but pups born in warrens located in open habitats survived significantly better than pups born in warrens located in closed habitats (50% vs. 30% of the pups born). As grass-dominated areas uphold the highest densities of domestic sheep and habitat modification due to overgrazing is a widespread process across arid Patagonia, effects on the availability of suitable breeding sites for maras are likely to occur and require further investigation.
DISTRIBUTION. Dolichotis patagonum only inhabits Ar-
gentina and is distributed from 288S to 508S (Fig. 3; Honacki et1982). D. p. centricola occurs in Catamarca Province, the eastern
region of La Rioja Province, the northwest of Córdoba Province,
and the southwest of Santiago del Estero Province (Cabrera 1953).
D. p. patagonum occurs in the central area of Buenos Aires Prov-
ince, the south of Córdoba Province, San Luis and Mendoza Prov-
inces, and to the south of Argentina to Santa Cruz Province (Ca-
brera 1953).
FOSSIL RECORD. Fossils of D. patagonum are known
from Luján in Buenos Aires Province and from near Córdoba
(Ameghino 1916). The Caviidae apparently derived from the Eocar-
diidae and first appeared in the middle Miocene, represented byspecialized subfamily, the Cardiomyinae (Landry 1957; Patterson
and Wood 1982; Wood and Patterson 1959). Ancestors of Dolicho-
tinae appeared in the Mesopotamian in the late Miocene, repre-
sented by Paradolichotis (Landry 1957).
Ecological physiology examines how animals cope with changing environmental demands. In low-productivity desert habitats, small mammals should consume low-quality, high-fiber food as a consequence of necessity rather than by choice. Diet quality of populations can differ at both spatial and temporal scales. Nevertheless, spatial and temporal variation in the digestive system has not been extensively studied in the field. We captured indi-viduals from 4 populations of Microcavia australis and measured their digestive morphological traits. Fieldwork was carried out in 4 localities belonging to arid and semiarid regions, in dry and wet seasons. We also estimated diet quality for each population and season. We found significant effects of sex, season, and site on the size of digestive organs. The concentration of fiber and nitrogen in the plants consumed differed between populations and varied seasonally: dietary fiber was higher in the dry season and nitrogen concentration was higher in the wet season. As predicted by theory, the cecum, the organ most closely related to cellulose fermentation, was sig-nificantly larger in animals facing the lowest quality diet. The other organs also were affected by reproductive state and water requirements. Intraspecific variation in the digestive morphology of M. australis probably helps this species cope with remarkable seasonal and geographical variability.
The caviomorph rodents from the San Andrés Formation are revisited. The fossiliferous stratigraphic unit outcrops in the coastal cliffs of the Chapadmalal area (east-central Argentina), and represents the Late Pliocene (Upper Marplatan Stage, Sanandresian Substage). A new species of Cavia (Caviidae) and unpublished materials of Dolichotis salinicola (Caviidae) and Abrocoma (Abrocomidae) are described, and the taxonomic status of the previously described taxa is briefly discussed. The living taxa Cavia, D. salinicola and Abrocoma are first recorded in the San Andrés Formation, and the extinct Abalosia (Octodontidae) is exclusive of this formation. The specimens of Abrocoma represent the single undoubted record of the living genus. The record of D. salinicola, Abalosia, Abrocoma and the octodontid Ctenomys represents an immigration event to east-central Argentina. This fauna from San Andrés is the extinct caviomorph assemblage most clearly indicative of arid environments so far recorded. Its episodic character and composition, and the available palaeomagnetic data, reinforce the hypothesis that it is probably coeval with the profound Late Pliocene cooling and drying pulse detected worldwide around 2.5 Ma. The Sanandresian immigrant taxa would have inhabited the emergent semi-deserts of western Argentina, and may have reached the more eastern Chapadmalal area during an expansion of such arid environments triggered by this Late Pliocene cooling and drying pulse.
Six captive maras (Dolichotis patagonum) were found to have cysts consistent with Besnoitia in the lungs by light microscopy and electron microscopy. Three were juveniles that died with no premonitory signs during a 17-month period. The most prominent finding consisted of severe, subacute, diffuse interstitial pneumonia with syncytia and Besnoitia cysts. The severity of pneumonia correlated with the number of cysts and the presence of lytic cysts, often surrounded by chronic granulomatous inflammation. Disseminated infection was observed in one of these maras. The three other maras died of unrelated conditions and had a few Besnoitia cysts in their lungs with mild or no inflammation associated. This is the first report of besnoitiasis in maras and of its association with fatal interstitial pneumonia in any species. Although other agents may have caused the interstitial pneumonia described here, it is possible that zoites released from lytic cysts were involved in the development of this lesion.
Generalized cowpox infection in the Patagonian cavy may represent a threat to the health of immunocompromised persons. We report the first case of cowpoxvirus infection in the Patagonian cavy in an educational animal park. The mara developed extensive pox lesions, shedding large amounts of viral particles. The ending of vaccination programmes against smallpox in the late 1970's may lead to an increase in susceptibility of humans to zoonotic poxviruses.
Guinea pigs are popular pets for both adults and children, and they are often presented to the small animal practitioner for medical problems. Diseases and management problems seen in pet guinea pigs often vary from those commonly seen in laboratory animals, and the treatment techniques used in pet animals also are different. This article reviews pet guinea pigs' common medical problems and treatment.
In maras (Dolichotis patagonum) several pairs raise their offspring in one warren where the young form a creche. The combination of monogamy and communal denning shown by maras is unique in mammals. During a five month study 10 (5 female female, 5 male male) young were born. After establishing an ethogram, data were collected on social and individual behaviour (outside the warren) and inter-pair distances were categorised. Juvenile development until sexual maturity can be divided into 3 phases: hider stage (1st-3rd week), follower stage (4th-13th week) and the time after weaning (from the 14th week). Hiders remain in the surroundings of the den. ''Followers'' leave the den during the day to graze with their parents until they are weaned. In hiders, social contacts occurred mainly with siblings and creche-members. Extensive play behaviour and varied body contacts (including huddling) were observed in this phase. In followers, interactions with their mothers and siblings occurred most frequently, but this was reduced to nursing contacts and maintaining close proximity. The transition from hider to follower stage is indicated by a sudden decrease in play and social behaviour. The first week of life is a phase of short inter-individual distances with the young being frequently sniffed by group members.
Maras, Dolichotis patagonum, were observed and radio-tracked in Argentina. They travelled as monogamous pairs that bred either alone at solitary burrows or communally at settlements where up to 29 pairs shared warrens.
Members of a mara settlement grazed within 2.5 km of the communal warrens, using intensively about 1 ha per day, within drifting daily ranges of 11 ha, seasonal ranges of 98 ha and annual ranges of 193 ha.
Their home ranges drifted continuously. Consequently, the long-term movements of neighbouring pairs overlapped substantially, but at any given moment they were territorially spaced.
Monogamous, drifting territoriality is explained by the patchy dispersion of food, the need to minimize interference competition, and a cycle of grazing and fallowing in the use of food plants.
Two hypotheses explaining the adaptive significance of settlements are evaluated: one relates to resource availability (through the indirect effect of ground water and sheep dung on vegetation); and the other relates to predation (through the protective influence of human dwellings). The size of sheep flocks grazing at outstations during January provide a measure of the resource richness of patches where maras graze, and the richness of these patches in the dry season appear to limit the number of maras breeding at each settlement during the following wet season.
Maras face extremes of resource dispersion between the wet and dry seasons: in the former, sparsely dispersed grazing and interference competition favour spacing out and territoriality; in the latter, clumping of resources facilitates pairs congregating in herds around outstations and dry lagoons. Superimposed upon the ecological factors favouring spacing out during the wet season are the sociological factors that cause the maras to den communally. The resulting compromise is a social system unique among mammals.
Topographic‐anatomical description of the ventriculus, intestinum tenue, intestinum crassum and their arteries of the mara ( Dolichotis patagonum Desmarest 1820)
The abdominal parts of the alimentary canal and the associated arteries from seven male and nine female maras are described. The mara possesses a stomach with a single cavity and a glandular mucosa lining. The large stomach is situated caudal of the liver at right‐angles to the longitudinal body axis. The long jejunum is located on the left side of the body caudal of the stomach. The cecum has two teniae and numerous haustra which are proximal larger than distal. The smooth colon ascendens runs proximal parallel to the cecum and describes distal an U‐shaped double‐loop. The internal surface of the proximal part of the colon ascendens is characterized by two parallel mucosal ledges. Cecum and colon ascendens lie right caudal of the liver. The colon descendens is coiled and situated on the left body side. The A. gastrica sinistra and branches of the A. lienalis and the A. hepatica supply the stomach. The A. mesenterica cranialis which branches off separately from the A. coeliaca is a large and long vessel that supplies the major parts of the small intestine and the colon. The A. mesenterica caudalis supplies parts of the colon desendens and of the rectum.
Mara social organization involves a combination of monogamous territoriality and co-operative, communal breeding that has not otherwise been described among mammals.
Some pairs reared their young in communal warrens, and pup survival was greater in warrens with larger memberships.
Pairs visited their young once daily, and females resisted, sometimes unsuccessfully, the attempts of interloping youngsters to nurse. Stolen nursing facilitated the survival of orphans.
More adults were present at larger creches, and total vigilance was thus increased despite each pair spending less time sitting-alert and less time at the warren. The proportion of the day for which at least one pair was vigilant at the warren increased to 90% with larger creche sizes.
Pups were much more likely to emerge from the warren when adults were present, and in the absence of adults were more likely to be sitting-alert close to the entrance.
These observations are compatible with hypotheses explaining the mara's social system in terms of resource dispersion, anti-predator behaviour and thermoregulation.
1. Digestibilities of feed and turnover time (1/k), transit time (TT) and mean retention time (MRT: 1/k+TT) of fluid and particle markers were measured in maras (Dolichotis patagonum) and guinea-pigs (Cavia procellus) fed a diet containing 50% alfalfa. 2. The digestibility of fibre was similar in both animals, however, the digestibilities of crude protein (nitrogen x 6.25) and crude ash were lower in the mara than in the guinea-pig. 3. 1/k of the digesta markers were similar in both animals, suggesting that the two animals possess similar dilution and retention time of digesta in their caecum and proximal colon.
Although the number of rodents kept as pets is increasing in the United States, much of the veterinary information that is known regarding their care is derived from laboratory animal medicine. This article describes individual species variation of medication delivery methods and the associated risks of antibiotic usage. A comprehensive formulary is also included.
An 8-week-old female Patagonian cavy was examined because of acute right hind limb lameness; radiography revealed a moderately displaced, comminuted fracture of the proximal third of the tibia. The fracture was stabilized with a hybrid external skeletal fixator. Two Kirschner wires were placed in the main proximal fragment, parallel to the tibial plateau and at right angles to each other. These wires were connected to a partial circular external fixator ring. Three half pins were placed in the distal fragment, and a straight connecting rod positioned on the medial side of the limb was connected to these pins and the fixator ring. A second connecting rod was positioned on the craniomedial side of the limb and was connected to the fixator ring and a fourth half pin in the distal fragment. The fracture healed without complications, and the fixator was removed 3 weeks after surgery. Hybrid external skeletal fixators combine the benefits of circular and linear external skeletal fixation methods, enabling rigid fixation of periarticular long bone fractures without adversely affecting mobility of the adjacent joint.
This paper describes the causes of death of 54 maras (Dolichotis patagonum) in a captive colony in Mexico over a period of seven years. There were 35 adults, 11 juveniles, five neonates, two fetuses and one stillbirth--27 males, 21 females and six whose sex was not determined. Trauma was the cause of 25 deaths, and there were eight cases of fatal bacterial infection. Besnoitiosis was the only parasitic disease found frequently (13 cases), and was associated with fatal interstitial pneumonia in three juveniles. Right-sided hypertrophic cardiomyopathy attributed to high altitude was observed in 26 maras, and in three cases death was attributed to acute cardiac dysfunction. Two maras died of disseminated histoplasmosis and two of hyperthermia. Additional causes of death included one case each of uterine torsion, intestinal intussusception, aspiration pneumonia and hydranencephaly. Gastric erosions with luminal haemorrhage were found in 27 of the maras and splenic lymphoid depletion in 20, changes that were attributed to stress.
Basic husbandry and medicine of pocket pets
- Andersen
Antimicrobial drug use in rabbits, rodents and other small mammals
- Collins
The hand-rearing of an 8-day-old mara (Dolichotis patagonum) and its subsequent reintroduction into the group at Suffolk Wildlife Park
- Prior
Dolichotis patagonum
- Campos
Handrearing members of rodentia
- Edwards