Small Exotic Mammals Research Articles

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

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.

Evaluation of the clinical presentation and histologic lesions of hepatic copper accumulation in sugar gliders (Petaurus breviceps)

Hepatic toxicosis caused by copper accumulation has been reported in most domestic species, as well as multiple small exotic mammals, including ferrets, fruit bats, and sugar gliders. The purpose of this study was to determine the signalments, clinical presentations, and histologic findings associated with hepatic copper accumulation in sugar gliders based on post-mortem histologic findings and retrospective analysis of reported antemortem clinical signs. Sugar gliders with histologic evidence of various hepatopathies were identified within the Northwest ZooPath archive. Sections of formalin-fixed, paraffin-embedded hepatic samples were stained for copper, and copper deposition was graded semiquantitatively. The prevalence of copper accumulation in the evaluated hepatopathies was 28%. Copper deposition was seen in all individuals with icterus and non-ataxia neurologic signs. Grossly, individuals with hepatic masses and nodules were 5.50 times more likely to have hepatic copper accumulation. Sugar gliders with biliary hyperplasia were 16.20 times more likely to have copper accumulation while all individuals with cholestasis had hepatic copper accumulation. The results of this study indicate that hepatic copper accumulation is frequently identified in post-mortem evaluation of sugar gliders with hepatopathy. Copper accumulation is frequently noted in individuals with icterus, neurologic abnormalities, hepatic masses, biliary hyperplasia, and cholestasis. This study details the prevalence of hepatic copper accumulation in sugar gliders and illustrates associations between copper hepatotoxicosis and other hepatic diseases.

Small mammal anaesthesia nursing

This article provides an outline of special considerations and requirements for the anaesthesia of small exotic mammals. This includes the process from pre-anaesthesia, induction, maintenance and monitoring, and recovery. Most small mammal species can be anaesthetised using revised techniques and equipment from companion animal anaesthesia, however the requirements for modified equipment and monitoring are discussed in this article.

Paradoxical Vestibular Syndrome Secondary to Temporal Bone Osteomyelitis and Chronic Otitis Interna in a Guinea Pig (Cavia porcellus)

A 3-year-old female intact guinea pig (Cavia porcellus) was presented for torticollis and ocular discharge. On examination, the guinea pig had a left head tilt with corneal ulceration and absent palpebral response of the right eye. Computed tomography showed a soft tissue attenuating mass with multifocal mineralization compressing the caudal cerebellum with moderate lysis of the calvarium. On recheck, the disease had progressed to include ataxia and proprioceptive deficits. Systemic antibiotic therapy was initiated but the guinea pig only exhibited a marginal treatment response. Due to poor quality of life, the guinea pig was euthanized. A necropsy was performed and a bony lesion was found within the skull compressing the right cerebellum and temporal lobe. Histopathology revealed suppurative osteomyelitis consistent with severe chronic bacterial otitis interna. Vestibular signs in small exotic companion mammals are a common sequela to otitis interna, often noted ipsilateral to an affected inner ear, however, in this case rare paradoxical vestibular signs were observed. Severe chronic otitis interna may result in bony lysis and proliferation capable of expanding from the inner ear resulting in neurological deficits.

Zoonotic Potential of Dermatophytosis in Small Mammals

Zoophilic dermatophytes play an important role in animal and human health. Small exotic mammals can be infected with a variety of dermatophytes that inhabit the fur, skin, nails, environment, cage, and/or soil. Humans are susceptible to these organisms; however, younger or immunocompromised individuals and people with intensive contact with pets are particularly susceptible to infection. The most important dermatophytes for small mammals are Trichophyton mentagrophytes, Trichophyton erinacei, Trichophyton quinckeanum, Arthroderma benhamiae, Arthroderma vanbreuseghemii, Microsporum gypseum, and Microsproum persicolor. Dermatophytes elicit a host inflammatory response, pruritus, which results from a cell-mediated hypersensitivity to fungal wall antigens. Erythema, excoriations, crusts, hyperkeratosis, alopecia, and secondary bacterial dermatitis are common clinical findings. In small mammals, infection can be self-limiting and serious consequences are relatively rare. A definitive diagnosis is primarily achieved through external physical examination, Wood’s lamp examination, direct microscopy of tape preparations and skin scrapings, and microscopic visualization of conidia after culture. Effective therapy for dermatophyte infection includes topical application of appropriate antifungal drops, sprays or spot-on products, bathing (e.g., enilconazole, clotrimazole, and miconazole), and parenteral antifungals (e.g., itraconazole and griseofulvin). To prevent reoccurrence or new infections, appropriate veterinary examination and quarantine of every new animal and appropriate treatment of affected small mammals and their environments are advised. Veterinarians should also inform local health authorities, pet shop employees, their staff, and especially hedgehog handlers about dermatophyte infection risks.

Neurological Diseases of Rabbits and Rodents

Clinical signs of neurological disease, such as head tilt, hind limb paresis or paralysis, seizures, and muscle weakness, are commonly encountered in pet rabbits, and in the authors׳ experience, less often in rodent species. Moreover, localisation of neurological lesions and establishment of a definitive diagnosis can be challenging for any of the exotic small mammal species. In many rabbit and rodent cases, distinguishing neurological disease from musculoskeletal disease is difficult. The parasitic disease encephalitozoonosis is commonly diagnosed in pet rabbits; in both rabbits and rodents, bacterial infections are also a common underlying cause of neurological disease. Other causes of neurological diseases that adversely affect pet rabbits and rodents include toxins, trauma, metabolic and degenerative disorders, viral infections, neoplasia, and hereditary abnormalities.

Bartonella species in small mammals and their potential vectors in Asia

In this article, authors review the current knowledge of Bartonella infection in small mammals including rodents, insectivores, bats and exotic small mammal pets and their vectors in Asia. Species of Bartonella are Gram-negative intracellular bacteria that infect erythrocytes of various mammalian and non-mammalian animals and mainly transmitted by blood sucking arthropod vectors. The genus Bartonella includes several species of important human diseases with severe clinical signs. Several new Bartonella species were isolated from rodents and other small mammals, and from human patients in Asia. Bartonella species are identified using standard polymerase chain reaction amplification and a sequencing targeting two housekeeping genes (gltA and rpoB) and the internal transcribed spacer fragment. Authors also discuss the implications in term of potential emerging zoonotic diseases.

Successful cardiopulmonary resuscitation following cardiopulmonary arrest in a geriatric chinchilla

To describe the successful application of CPR in a geriatric chinchilla employing basic and advanced life support measures during cardiopulmonary arrest (CPA). A 13-year-old female intact chinchilla presented to a general and multispecialty referral hospital for a dental procedure. During recovery from anesthesia the patient suffered CPA and CPR was initiated. Noninvasive positive pressure mask ventilation was initiated and external chest compressions were performed. An 18-Ga needle was introduced into the medullary cavity of the right humerus as an intraosseous catheter and provided access for administration of drugs and fluids. After return of spontaneous circulation was noted mannitol was administered via the intraosseous catheter to alleviate suspected increased intracranial pressure. Clinical improvement was noted shortly after administration. Monitoring during the recovery period showed a normal sinus cardiac rhythm and a SpO₂ of 100% while on supplemental oxygen. Neurologic function continued to improve over the following hours. Oxygen therapy was provided via an oxygen cage, and administration of antimicirobials, gastrointestinal protectants, and nutritional supplementation were part of the post resuscitation care. Oxygen therapy was discontinued after 24 hours, during which time normal behaviors were observed and neurologic status was considered appropriate. The patient was discharged 48 hours after CPA. Published reports from clinical practice on the outcomes of CPR for exotic small mammals are limited. This report details the successful outcome of the use of combined basic and advanced life support measures for the provision of CPR in a chinchilla. This report also highlights the utility of an intraosseous catheter for administration of drugs and fluids novel to this species during resuscitation and recovery. To the authors' knowledge this is the first published report of successful CPR following CPA in a geriatric chinchilla.

Emergency Presentations Associated with Cardiovascular Disease in Exotic Herbivores

Exotic animals, including small herbivores, are increasing in popularity as companion animals. Commonly owned exotic herbivores include guinea pigs, chinchillas, and rabbits. These animals fall into the category of prey species with an inherent instinct to hide their illness until severely affected by the disease process. Therefore, any of these animals presented as an emergency case must be carefully evaluated for chronic underlying illness. Cardiovascular emergency and critical care principles are similar across all mammalian species. However, specialized techniques and adaptations are occasionally required because of the unique physiology and natural behaviors of these animals. It is essential to evaluate and stabilize these patients before attempting definitive diagnostic plans. Emergency cardiovascular presentations, as in other mammals, consist of congestive heart failure, arrhythmias, pericardial effusion, and toxicities that can result in cardiac and pulmonary arrest. Cardiac disease is a relatively common finding in small exotic mammals, but there are few peer-reviewed reports regarding diagnosis and treatment of heart disease in these species. Diagnostic testing and treatment options are generally based on knowledge of small animal medicine.

Emergency Presentations of the Exotic Small Mammalian Herbivore Trauma Patient

Trauma is a common complaint by owners of small exotic mammalian herbivores (e.g., rabbits, rodents) presented to veterinary hospitals. The term “trauma” is a broad disease category applied to patients with physical debilitation associated with injury often classified as “blunt,” “penetrating,” or “burn” in origin. Because many small exotic mammalian herbivores are prey animals, clinical signs of trauma may be masked until the effects of the injury outweigh the innate nature to survive. Small exotic mammalian herbivores are disproportionately sensitive to stress; thus, pain management and supportive care are extremely important during the initial stages of trauma management. Small exotic mammals differ slightly from other companion animals (e.g., dogs, cats) in regard to common trauma presentations. However, with a few therapeutic modifications (e.g., antibiotic selection, avoidance of corticosteroids, preventing self-trauma), treatment of small exotic mammalian herbivore trauma cases follows the same conventional guidelines used for other companion animals.

Understanding the inter-specific dynamics of two co-existing predators in the Tierra del Fuego Archipelago: the native southern river otter and the exotic American mink

Knowledge about interactions between endangered native southern river otters (Lontra provocax) and introduced American mink (Neovison vison) is essential for effective management of both species. We evaluated competition for spatial and trophic niches between otter and mink in overlapping and non-overlapping areas, comparing distribution, habitat preference, diet and mink marking behavior. We surveyed otter and mink signs along 250 km of Beagle Channel coastline. Habitat suitability models were constructed based on species presence/absence and habitat characteristics, using generalized linear models. Feces were collected for diet analyses. Otters used forested coasts with 12°–32° shoreline slope and without human influence, and our evidence suggests they were not affected by mink presence. Mink preferred forested and shrubland coasts with 10°–28° shoreline slope. Neither human influence nor otter presence affected mink habitat occupation, but in the presence of otters, mink left fewer signs. Otters consumed more aquatic prey than mink, and mink modified their diet in the presence of otters, consuming more exotic small terrestrial mammals and less fish as well as shifting to smaller and shallower fish species that are less consumed by otters. Mink showed more plastic, generalist behavior than otters, being more tolerant of human presence, using more habitat types and having greater diet breadth. At the same time, otters apparently affect mink adversely and could help limit their invasion in sympatric areas. Conservation and recovery of otters, therefore, may produce a secondary benefit of simultaneously reducing the effect of mink, thereby providing an additional way to control this exotic predator’s population.

Clinical Technique: Ultrasound-Guided Fine-Needle Aspirate in Ferrets

Ultrasound-guided fine-needle aspiration of organs and structures within the body cavity reduces the risk of iatrogenic injury to important anatomic structures compared with blind sampling. Through visualization of the needle entering the target tissue there is an increased chance of obtaining the desired samples while reducing the possibility of complications. The increased use of ultrasound imaging to assess and diagnose exotic animal patients makes this an excellent modality to expand its use from strictly a visual diagnostic aid. Ultrasound-guided fine-needle aspiration has been used to collect tissue samples from many species of small exotic mammals, reptiles, and birds.

Use of rigid endoscopy to evaluate vaginal haemorrhage in a rat

ENDOSCOPY provides a minimally invasive method for diagnostic sampling (eg, for biopsy, cytology or cultures) and visual examination of internal structures. This diagnostic modality is especially advantageous in small exotic...

Clinical Technique: Endoscopic Oophorectomy in the Rabbit ( Oryctolagus cuniculus): The Future of Preventative Sterilizations

Laparoscopic surgery is entrenched within human medicine and offers many advantages over traditional laparotomy procedures. Such techniques have filtered down into veterinary medicine, with some practitioners now routinely performing endoscopic oophorectomy in dogs. However, until the recent development of miniature laparoscopy instruments for human pediatrics, such procedures were not possible in small exotic mammals. By combining the commonly used 2.7-mm endoscopic system with 3-mm instruments, laparoscopic surgery has now become a reality in exotic mammal practice. This article summarizes the required equipment and the surgical approach to performing endoscopic oophorectomy in pet rabbits, and serves as a useful model for endosurgery in small exotic mammals.

Consumer‐based limitations drive oak recruitment failure

A number of North American oaks are experiencing recruitment failure, with explanatory hypotheses including a range of consumer- or resource-based limitations. Using a factorial experiment with transplanted seedlings, we demonstrate how direct and indirect consumer effects prevent recruitment by Quercus garryana, a keystone savanna species of northwestern North America. Foremost, intense herbivory by mostly exotic small mammals severely damaged or killed 100% of unprotected seedlings during winter. Many damaged seedlings survived but were 64% smaller in size and produced 75% fewer leaves. Herbivory by deer had no detectable impact despite being long hypothesized as a major contributor to oak decline. Indirectly, herbivory altered the outcome of moisture limitation and competition. Without small mammals, summer drought and a dense exotic grass cover associated with fire suppression significantly reduced growth but caused little mortality. With small mammals, both significantly increased mortality of herbivore-damaged seedlings. Herbivore damage also increased the likelihood of severe insect attack, possibly due to reduced investment in foliar defense by recovering seedlings. These results show that no single factor necessarily prevents seedling establishment by oaks, but that the combination of herbivory, undisturbed exotic grass swards, and summer drought creates an almost insurmountable barrier for recruitment.

Diagnostic Challenge

Exotic animals, including small herbivores, are increasing in popularity as companion animals. Commonly owned exotic herbivores include guinea pigs, chinchillas, and rabbits. These animals fall into the category of prey species with an inherent instinct to hide their illness until severely affected by the disease process. Therefore, any of these animals presented as an emergency case must be carefully evaluated for chronic underlying illness. Cardiovascular emergency and critical care principles are similar across all mammalian species. However, specialized techniques and adaptations are occasionally required because of the unique physiology and natural behaviors of these animals. It is essential to evaluate and stabilize these patients before attempting definitive diagnostic plans. Emergency cardiovascular presentations, as in other mammals, consist of congestive heart failure, arrhythmias, pericardial effusion, and toxicities that can result in cardiac and pulmonary arrest. Cardiac disease is a relatively common finding in small exotic mammals, but there are few peer-reviewed reports regarding diagnosis and treatment of heart disease in these species. Diagnostic testing and treatment options are generally based on knowledge of small animal medicine.

Butorphanol

Trauma is a common complaint by owners of small exotic mammalian herbivores (e.g., rabbits, rodents) presented to veterinary hospitals. The term “trauma” is a broad disease category applied to patients with physical debilitation associated with injury often classified as “blunt,” “penetrating,” or “burn” in origin. Because many small exotic mammalian herbivores are prey animals, clinical signs of trauma may be masked until the effects of the injury outweigh the innate nature to survive. Small exotic mammalian herbivores are disproportionately sensitive to stress; thus, pain management and supportive care are extremely important during the initial stages of trauma management. Small exotic mammals differ slightly from other companion animals (e.g., dogs, cats) in regard to common trauma presentations. However, with a few therapeutic modifications (e.g., antibiotic selection, avoidance of corticosteroids, preventing self-trauma), treatment of small exotic mammalian herbivore trauma cases follows the same conventional guidelines used for other companion animals.

CONSUMER-BASED LIMITATIONS DRIVE OAK RECRUITMENT FAILURE

A number of North American oaks are experiencing recruitment failure, with explanatory hypotheses including a range of consumer- or resource-based limitations. Using a factorial experiment with transplanted seedlings, we demonstrate how direct and indirect consumer effects prevent recruitment by Quercus garryana, a keystone savanna species of northwestern North America. Foremost, intense herbivory by mostly exotic small mammals severely damaged or killed 100% of unprotected seedlings during winter. Many damaged seedlings survived but were 64% smaller in size and produced 75% fewer leaves. Herbivory by deer had no detectable impact despite being long hypothesized as a major contributor to oak decline. Indirectly, herbivory altered the outcome of moisture limitation and competition. Without small mammals, summer drought and a dense exotic grass cover associated with fire suppression significantly reduced growth but caused little mortality. With small mammals, both significantly increased mortality of herbivore-damaged seedlings. Herbivore damage also increased the likelihood of severe insect attack, possibly due to reduced investment in foliar defense by recovering seedlings. These results show that no single factor necessarily prevents seedling establishment by oaks, but that the combination of herbivory, undisturbed exotic grass swards, and summer drought creates an almost insurmountable barrier for recruitment.

Evidence-based Medicine in Small Mammals

Evidence-based medicine in small exotic mammals is often considered challenging because of a lack of information related to reference data, validated diagnostic tests, treatment outcome, side effects, long-term prognosis, and financial constraints of the owner. However, despite this lack of information, it is still possible to provide good medical care to small exotic mammals and confirm a disease diagnosis that can be properly treated. With many small exotic mammal cases, the condition of the animal and, ultimately, the disease diagnosis, may not be familiar to the attending veterinarian, and in some cases the disease itself may not have ever been described in that species in the scientific literature. This article describes the process of diagnosing hyperthyroidism in a guinea pig using a recommended patient assessment, diagnostic, and treatment protocol.