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Hamsters and gerbils
Abstract
This chapter provides an overview of the biology and medical care of hamsters and gerbils. The golden hamster is the largest of the common pet species, with an average body weight of 120 g. Other hamster species commonly found in the pet trade are the Chinese hamster and the Siberian or dwarf hamster. Enclosures for hamsters and gerbils should be easy to clean, lightweight, and should have a plastic bottom and sides deep enough to contain bedding. Additionally, these enclosures should be well ventilated. Large door/doors should be provided for removal of the animal from the cage. Small plastic heavy dishes are recommended for food and sipper bottles for water. Water deprivation is a common problem in pet rodents and should be avoided by inspection of sipper bottles or water containers daily for function, water level, and cleanliness. Hamsters and gerbils should be kept in a clean environment to avoid disease problems. Food and water containers should be cleaned with dilute soap weekly and washed free of debris on a daily basis. Enclosures should be thoroughly cleaned on a weekly basis, by removing all bedding and cleaning the enclosure with soap and hot water. Solid plastic cages should be cleaned more regularly as they have less ventilation. Inspection and removal of solid and liquid wastes should occur on a daily basis. As a general rule, if one can smell the enclosure, it must be cleaned. Many rodents suffer mortality and morbidity from ammonia build-up and improperly cleaned or maintained enclosures.
... Housing groups of hamsters or introducing a new hamster into another hamster's cage is not recommended, because cagemate trauma will likely result. 11 The recommended diet for hamsters is commercial formulated hamster pellets or blocks. Seedbased diets are lacking in a number of the nutritional requirements needed to maintain long-term health and prevent disease, especially osteoporosis. ...
... Commercial blocks or pellets with more than 16% protein and 4% to 5% fat are recommended. 3,11 Seed-based diets are not recommended, nor is significant supplementation of fruits, nuts, vegetables, cheese, or other human foods. Occasional treats should be limited to those high in protein and low in fat. ...
... Warming the tail for 15 minutes before sample collection will aid in vessel visualization. 3,8,11 In mice and hamsters, venipuncture must be performed with the animal under anesthesia. A warmed ventral tail vein or artery and the anterior vena cava may be used for blood collection in mice. ...
AbstractRodent species are routinely presented to veterinary hospitals for wellness checks and different illnesses. When rodents are presented to the veterinarian for diagnosis and treatment, they deserve the same thorough approach that any other domestic species receives. The purpose of this article is to provide readers a review of the current information regarding examination, diagnosis, and treatment of some of the most common conditions for which rodent patients are presented. This article will cover 5 of the most common rodent species presented to veterinarians: guinea pigs, chinchillas, rats, mice, and hamsters.
... On the other hand, MCV and RDW-SD indices in the experimental group were elevated in comparison with the control group (p < 0.05) ( Table 7). However, (Heatley & Harris, 2009). ...
... Blood indices of tested mice semi-chronic toxicity experiment compared to hamster Syria mice(Heatley & Harris, 2009).Values are given as mean ± SD of triplicate experiment. ...
... Due to its simplicity and convenience, the oral route is often preferred. Nevertheless this route is less advisable when the drug is not acid stable or irritating to the gastro-intestinal tract, or when the patient is vomiting or unable to swallow [280][281][282] . Moreover, oral gavage or forced feeding can result in passive reflux, aspiration pneumonia, gastric irritation or ruptures and rises stress levels in animals and thus requires specific skills to be executed 281 . ...
... Parental forms of administration include all other routes not involving the gastro-intestinal tract, e.g. intravenous, intramuscular, subcutaneous or transdermal [280][281][282] . When the drug is characterized by low bioavailability or there is the need for immediate effects, these routes are preferred. ...
... Our results revealed that terrestrial rodents' erythrocytes averaged 5.5 to 6.7 μm in diameter, and are consistent with earlier reports (Wyckoff & Frase, 1990;Frase, 2002;Heatley & Harris, 2009). Free-living Murinae and Cricetidae are typically burrowing mammals adapting to hypoxia due to fossorial habit. ...
... Slip, or traumatic degloving of the tail skin, is occasionally observed in long-tailed rodents, such as degus, gerbils, and chinchillas (Fig. 11). 9,11,12 In these species, the skin of the tail is thin and can easily be torn from the underlying tissues by overzealous grasping of the tail or lifting the weight of the animal by the tail. Rather than grasping the tail, the individual should be manually restrained over the dorsal cervical region and the rest of the body supported with the other hand. ...
Small mammal surgical procedures are a part of clinical veterinary practice and are performed with regularity. Anesthetic and analgesic techniques are important components of any successful small mammal surgical procedure. Many basic surgical principles used in dogs and cats can be directly applied to small mammals, but tissues tend to be smaller and thinner, and hemostasis is critical with small patients due to risk of death with minimal blood loss. Common surgical procedures in small mammals include integumentary mass and abscess excision, reproductive procedures, gastrointestinal foreign body removal, urolith removal, prolapsed tissues associated with the gastrointestinal tract, intra-abdominal mass excision, and hepatic surgery.
The early diagnosis of canine leptospirosis is still a challenge for clinicians that in most cases only have basic routine tests as diagnostic tools. This study aimed to isolate and characterize leptospires from the blood of dogs with clinical signs suggestive of leptospirosis and to evaluate the results of some laboratory tests in hamsters experimentally infected with these isolates. The blood of 22 animals was submitted to bacteriological culturing, and the isolates recovered were characterized by serogrouping, partial DNA sequencing (secY), and multiple locus variable-number tandem repeat analysis (MLVA). Golden Syrian hamsters were infected with isolated leptospires and submitted to serology using microscopic agglutination test (MAT), polymerase chain reaction (PCR), complete blood counts, and serum biochemistry. Three isolates (13.63%) were obtained, and all were assigned to the serogroup Icterohaemorrhagiae. The DNA sequencing results showed that all the isolates belonged to the species Leptospira interrogans, and the MLVA results evidenced that the profile of the strains was compatible with Copenhageni/Icterohaemorrhagiae serovars. Regarding laboratory tests performed on hamsters infected with these isolated strains, marked leukocytosis by neutrophilia and monocytosis was observed, associated with an accentuated increase in renal and hepatic indicators. In addition, a titer of 800 was detected by MAT for only the serogroup Icterohaemorrhagiae, and blood, liver, kidneys, and lung samples were PCR positive. The presence of these isolates suggests that the dogs were infected with strains carried by rodents, and significant changes were found in routine laboratory tests, which, when correlated, can help veterinarians with early diagnosis.
With over 2200 extant species, rodents (order Rodentia) represent the largest mammalian order and comprise 42% of global mammalian biodiversity (Donnelly et al. 2015). Rodents represent a diversity of morphological adaptations associated with their varied terrestrial and aquatic habitats, distributed throughout all continents except Antarctica. One common feature to all Rodentia is a powerful anatomical apparatus for chewing and gnawing, characterized by prominent rostral dentition and a large and often complex masseter muscle. The differing morphological characteristics and adaptations of the zygomasseteric apparatus are used to divide the Rodentia into five suborders including the Anomaluromorpha, Castorimorpha, Hystricomorpha, Sciuromorpha, and Myomorpha (Wilson and Reeder 2005).
The hematology of laboratory and exotic mammals is similar in many respects to that of domestic mammals. However, obtaining meaningful reference values can be difficult due to variations associated with blood collection, laboratory procedures, and intrinsic and extrinsic factors. The hemograms of small mammals can vary dependent on age, sex, environmental conditions, and diet. A nonregenerative anemia associated with normal neutrophil (or heterophil) and platelet concentrations in the peripheral blood and a marked decrease in the population of bone marrow erythroid precursors without a decrease in granulocyte precursors and megakaryocytes is a pure erythrocyte aplasia. Inflammation is the most common blood leukocyte response in mammals. Evaluation of the number of megakaryocytes in the bone marrow may be necessary to determine if the thrombocytopenia is due to a defect in platelet production or caused by platelet destruction or consumption.
Hamsters and gerbils are often presented on an emergent basis. Common presenting complaints include diarrhea, neurologic signs, ocular signs, respiratory distress, and trauma. Provided is an overview of these presenting complaints, with additional detail on underlying conditions. Unique species considerations are addressed, and an abbreviated formulary of anticonvulsant, antimicrobial, and antiparasitic agents is provided.
Hamsters are one of the commonly used animal species in research related to virology and infectious agents. Hamsters are similar to human beings in many metabolic and physiological processes. Though the use of hamsters in research has declined in the last few decades, the genetically engineered Syrian hamster (GESH) model is seeing increased popularity due to advancements in gene-editing technologies like CRISPR/Cas9. The presence of immunologically privileged large highly distensible non-glandular cheek pouches makes hamsters a preferred model for oral carcinogenesis, microvascular investigations of inflammation, ischemia-reperfusion investigations, tumor development, and vascular smooth muscle function. Due to the unique immune system of hamsters, skin allografts are not rejected to the degree as compared to other models and have a higher susceptibility to certain infections. It is already known that for, cell culture experiments, Chinese hamster ovary (CHO) cells are extensively used. This chapter will briefly discuss general anatomy, physiology, husbandry, and reproduction, followed by references to reported research uses.
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.
The role of rodents as reservoirs of helminths of public health importance is not well known. The zoonotic potential of Syphacia spp. has been confirmed; therefore, the study aimed to estimate the occurrence of oxyurid nematodes in small rodents from pet shops and breeding clubs in Slovakia. Fecal samples of 586 pet rodents kept in 133 cages were collected between 2016 and 2018 and examined by Faust´s flotation method. Four species of oxyurid nematodes, Syphacia muris, S. obvelata, Aspiculuris tetraptera and Paraspidodera uncinata were detected. A. tetraptera was found in the faecal samples of all rodent species included in this survey. The number of positive boxes varied from 5.4% in hamsters to 70.0% with mice. The prevalence of Syphacia muris was highest in Mongolian gerbils where up to 75.0% boxes were positive; S. obvelata was found in 26.7% of boxes with mice, 25.0% of boxes with Mongolian gerbils and 3.2% of boxes with rats. The high prevalence of Syphacia spp. in all animal species points out the infection risk for humans. Animals offered for sale are often in close contact with human beings; therefore they should be regularly tested for parasites and then effectively dewormed.
Background
Liver vitamin A (VA) concentration is the gold standard for VA status, but is not routinely accessible. Adipose tissue VA concentrations, as retinol and retinyl esters, may be correlated to liver VA. α-VA (as α-retinol) is a cleavage product of α-carotene that traces postprandial VA distribution to tissues but cannot recirculate from hepatic stores, providing insight into tissue VA sources.
Objective
We performed a secondary analysis of VA and α-VA in Mongolian gerbil liver and adipose to determine the suitability of adipose tissue VA as a biomarker of VA status.
Methods
Gerbils (n = 186) consumed feeds containing 0–15.9 μg (0–55.6 nmol) retinol activity equivalents/g as preformed VA and/or provitamin A carotenoids for 36–62 d in 3 studies. Body fat percentage was determined in the final study by MRI. Serum and liver retinol, α-retinol, and retinyl esters were extracted and analyzed by HPLC or ultra-performance LC (UPLC). Epididymal and retroperitoneal adipose tissue retinol and α-retinol were determined by UPLC after homogenization, saponification, and extraction. Linear regression models with appropriate data transformations identified determinants of adipose VA concentrations.
Results
Liver VA did not predict serum retinol concentrations. After logarithmic transformation of adipose and liver values, liver VA positively predicted both adipose depots’ VA concentrations (P < 0.001, R² > 0.7). Adding serum retinol or body fat percentage did not significantly increase the adjusted R². In liver, α-VA concentration explained much of the variation of VA (P < 0.001, R² > 0.7), but far less in epididymal and retroperitoneal adipose (P = 0.004 and 0.012, respectively, R² < 0.4).
Conclusions
Adipose VA is correlated with liver VA and is a potential biomarker of VA status. It is not fully explained by chylomicron deposition and is negatively affected by serum retinol. Adipose biopsy validation is needed for human applications.
Reproduction diseases are common presentations in small rodents. Some can be presented to the clinician as an emergency where a fast and effective treatment is required. This article presents an overview of reproductive disorders in these species. Diseases affecting the ovary, uterus, testicles, and mammary gland are developed in rats, mice, hamsters, and gerbils: inflammatory, infectious, and neoplasia. Clinical signs, diagnosis, and treatment information are included. Some specific indications about the surgical reproduction procedures are described. Literature regarding reproductive disorders exists for squirrels and prairie dogs. Brief information about the normal anatomy of the reproductive system is given.
OBJECTIVE
To determine effects of diurnal variation and anesthetic agents on intraocular pressure (IOP) in Syrian hamsters (Mesocricetus auratus).
ANIMALS
90 healthy adult Syrian hamsters (45 males and 45 females).
PROCEDURES
IOP was measured with a rebound tonometer. In phase 1, IOP was measured in all hamsters 3 times during a 24-hour period (7 am, 3 pm, and 11 pm). In phase 2, hamsters were assigned to 5 groups (18 animals [9 males and 9 females]/group). Each group received an anesthetic agent or combination of anesthetic agents (ketamine hydrochloride, xylazine hydrochloride, diazepam, ketamine-diazepam [KD], or ketamine-xylazine [KX] groups) administered via the IP route. The IOP was measured before (time 0 [baseline]) and 10, 30, 60, 90, 120, and 150 minutes after administration of drugs.
RESULTS
Mean ± SD IOP values were 2.58 ± 0.87 mm Hg, 4.46 ± 1.58 mm Hg, and 5.96 ± 1.23 mm Hg at 7 am, 3 pm, and 11 pm, respectively. Mean baseline IOP was 6.25 ± 0.28 mm Hg, 6.12 ± 0.23 mm Hg, 5.75 ± 0.64 mm Hg, 5.12 ± 1.40 mm Hg, and 4.50 ± 1.30 mm Hg for the ketamine, xylazine, diazepam, KD, and KX groups, respectively. A significant decrease in IOP, compared with baseline IOP, was detected in only the KX group at 30, 60, and 90 minutes after drug administration.
CONCLUSIONS AND CLINICAL RELEVANCE
Maximum IOP in Syrian hamsters was detected at night. The ketamine-xylazine anesthetic combination significantly decreased IOP in Syrian hamsters.
A 2 year old castrated male Eastern fox squirrel (Sciurus niger) presented with a 3–4 week history of stranguria and intermittent lower urinary tract obstruction. A complete blood count, serum chemistry analysis, urinalysis, urine culture, radiographic imaging and ultrasonography helped formulate a diagnosis of severe chronic cystitis-induced lower urinary tract obstruction. The patient was treated using a pigtail drainage catheter followed by scrotal urethrostomy and abdominal exploratory surgery. Lower urinary tract disease and obstruction can occur sporadically in rodent species, resulting in presentation for hematuria, stranguria, decreased appetite, and lethargy. When complete obstruction occurs, urinary catheterization and/or surgical intervention are warranted. This case report demonstrates the use of scrotal urethrostomy for treatment of complicated lower urinary tract obstruction in a rodent species.
Small exotic mammal pets such as rats, mice, hamsters, gerbils, degus, hedgehogs, and sugar gliders are becoming more popular. Because these animals are prone to a variety of health problems, and require specialized husbandry care to remain healthy, they may present to emergency hospitals in critical condition. This article provides a basic overview of common emergency presentations of these species.
This study describes the surgery of fast-growing masses in the ventral neck and breast region of three dwarf hamsters (Phodopus sungorus/campbelli). The three lumps were completely excised using so-called "complete antagonis-able anaesthesia". The anaesthesia, surgery and recovery proceeded without any problems in all three hamsters. The histopathology of the three masses revealed different results: two cases of malignant mesenchymal neoplasia and a pyogranulomatous inflammation with intralesional bacteria were diagnosed.
Hamsters are used for a multitude of biomedical research purposes including studies in oncology, dentistry, cardiology, and neuroscience. The purpose of this chapter is to provide the reader with descriptions of specific techniques, or references to techniques, that have important applications in biomedical research. The chapter describes the general non-surgical procedures. Most laboratory hamsters do not relish being handled and can inflict a painful bite if given the opportunity to do so. There is a large amount of loose skin by the dorsal cervical area that can be used to restrain and lift the animal. Hamsters are often used in respiratory disease research.
This chapter discusses the clinical biochemistry and hematology of the rabbit (. Oryctolagus cuniculus), guinea pig (. Cavia porcellus), hamster (. Mesocricetus auratus), and other rodents, including the gerbil (. Meriones unguiculatus), chinchilla (. Chinchilla laniger), degu (. Octodon degus), deer mouse (. Peromyscus maniculatus), dormouse (. Gliridae family), kangaroo rat (. Dipodomys spp.), cotton rat (. Sigmodon hispidus), and sand rat (. Psammomys obesus). The chapter begins with a review of sample collection and preparation, and a description of commonly measured parameters and analytical techniques. The reference values, sources of variation, and unique characteristics are then presented for each species, as available. Many variables affect the parameters of clinical biochemistry and hematology including methods of sample collection and preparation, equipment, reagents, and methods of analysis, as well as the age, sex, breed, and environment of the animals being sampled. Values obtained from a clinical case are usually compared with reference values that are either produced in the same laboratory or in a similar group of animals, or cited in the literature. Optimal sites for blood collection vary between laboratory animals and are described in this chapter for each species for which information is available. Total blood volume of the rabbit is discussed in the Hematology section of the chapter. The rabbit is recognized as a valuable model for human disturbances in lipid metabolism, such as the metabolic syndrome and hypercholesterolemia leading to atherosclerosis. Hematology is the study of blood and blood-forming organs, including the diagnosis, treatment, and prevention of diseases of the blood, bone marrow, and immunologic, hemostatic, and vascular systems. Hematologic analysis is often used for the diagnosis and treatment of animal diseases.
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.
Nine groups of rats (n = 5 per group) received an intramuscular (IM) injection of one of the following drugs or drug combinations: saline, atropine (0.05 mg/kg), glycopyrrolate (0.5 mg/kg), ketamine:xylazine (85:15 mg/kg), ketamine:detomidine (60:10 mg/kg), atropine:ketamine:xylazine (0.05: 85:15 mg/kg), glycopyrrolate: ketamine:xylazine (0.5:85:15 mg/kg), atropine:ketamine:detomidine (0.05: 60:10 mg/kg) or glycopyrrolate: ketamine:detomidine (0.5:60:10). Similarly six groups of rabbits (n = 5) received an IM injection of either saline, atropine (0.2 mg/kg), atropine (2 mg/kg), glycopyrrolate (0.1 mg/kg), ketamine:xylazine (35:10 mg/kg) or glycopyrrolate:ketamine:xylazine (0.1:35:10 mg/kg). In rats, atropine sulfate (0.05 mg/kg) and glycopyrrolate (0.5 mg/kg) produced an increase in heart rate for 30 and 240 min, respectively. In rabbits atropine sulfate at either 0.2 or 2.0 mg/kg did not induce a significant increase in heart rate, but glycopyrrolate (0.1 mg/kg) elevated the heart rate above saline treated animals for over 50 min. Both atropine and glycopyrrolate provided protection against a decrease in heart rate in rats anesthetized with ketamine: xylazine (85:15 mg/kg) or ketamine: detomidine (60:10 mg/kg); however, glycopyrrolate was significantly more effective in maintaining the heart rate within the normal range. Glycopprrolate also prevented a decrease in heart rate in rabbits anesthetized with ketamine:xylazine (35:5 mg/kg). Neither glycopyrrolate nor atropine influenced respiration rate, core body temperature or systolic blood pressure when used alone or when combined with the injectable anesthetic. Glycopyrrolate is an effective anticholinergic agent in rabbits and rodents and more useful as a preanesthetic agent than atropine sulfate in these animals.
More than 250 species of mites are recognized as the cause of health-related problems for humans and domestic animals. Types of problems include: (1) temporary irritation of the skin due to bites or feeding on host skin, fur, and feathers; (2) persistent dermatitis in response to mites that invade the skin or hair follicles; (3) mite-induced allergies; (4) transmission of pathogenic microbial agents and metazoan parasites; (5) intermediate hosting of parasites, notably tapeworms; (6) invasion of respiratory passages, ear canals, and occasionally internal organs; (7) an abnormal fear of mites, or “acarophobia;” and (8) delusory acariosis, a psychological condition in which individuals are convinced that they are being attacked by mites when, in fact, no mites are involved. The general term for infestations of animals by mites is called “acarinism,” whereas any disease condition caused by mites is called “acariasis.” Mites comprise the arachnid subclass “Acari,” which is divided into two major groups: the Antactinotrichida and Actinotrichida. These are further subdivided into seven orders. The body is divided into two major regions: the anterior gnathosoma, bearing the pedipalps and chelicerae; and the idiosoma, the remainder of the body, bearing the legs and eyes. The basic developmental stages in the life history of mites are the egg, prelarva, larva, protonymph, deutonymph, tritonymph, and adult. Mites can adversely affect human health in many ways. They can infest homes including carpets, mattresses and bedding, clothing, stored food products, and household pets. The most widely recognized mite problems that affect human health are respiratory allergies caused by mites, infesting house dust.
Increasing numbers of exotic animals are being kept as pets, and owners want to receive high-quality medical care for these pets. Treatment of hypovolemic shock and critical care monitoring in exotic pets are complicated by small patient size, physiological diversity, and lack of research and clinical data on their response to therapy. Despite these impediments, the same principles and techniques of monitoring used in domestic animals can be applied to the exotic patient. The goal of this article is to provide an in-depth presentation on the principles and pathophysiology of shock, types of fluids, monitoring techniques, and shock resuscitation methods for use in rabbits, ferrets, small mammals, and birds. An understanding by the veterinarian of the patient’s cardiovascular state and the characteristics of crystalloid and colloid fluids available is necessary for establishing a fluid therapy plan. Arterial blood pressure measurement is an important tool in the management of the critically ill pet. The message of clinical importance is that fixed fluid regimens (eg, Lactated Ringers), fixed volumes (eg, mL/kg) and rules of thumb are in most instances outdated, inappropriate and often times inadequate. Appropriate fluid therapy, combined with frequent patient evaluation and periodic blood pressure monitoring techniques, can produce astounding and at times miraculous results.
Cardiopulmonary-cerebral resuscitation (CPCR) is a comprehensive term used to describe both the basic principles of cardiopulmonary resuscitation (CPR) as well as advanced life support and postresuscitation care. Although there are numerous publications on CPCR in humans and small animals, there is little written on CPCR in special species. This article outlines the basic principles of CPCR, including the current recommendations from the human International Guidelines 2000 Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Although many of the basic principles of CPCR are applicable to any species, the important physiologic differences when applying these principles to special species are discussed. When appropriate, potential modifications are proposed for individual species. The final portion of the paper includes special considerations for avian, reptile and small mammals, as well as quick reference charts for CPCR in small mammals and avian/reptile patients.
Special species, such as rabbits, ferrets, rodents, parrots, turtles, and snakes, are becoming more popular as pets. Thus, it becomes more likely that a veterinarian may be presented with one of these species on an emergent basis. This article addresses the basic steps of vascular and airway access for each group of special species and will provide information on techniques that can be used to enable the clinician to quickly obtain basic diagnostics and provide the patient with emergency life support. This article also briefly describes methods for humane euthanasia of special species pets.
Therapeutic drugs legally available for human use have gone through exhaustive pharacodynamic testing and clinical drug trials. Far fewer drugs have been evaluated for common companion animals such as dogs and cats, and practically none have been rigorously evaluated for the exotic patient. Much of our information on dosing, efficacy, and adverse reactions is anecdotal or based on extrapolation from other species. Very little information exists on drug-to-drug interaction in vivo. However, a few recognized therapeutic contraindications exist, and many have been well documented in the field of laboratory medicine. A common example is corticosteroid usage in laboratory rabbits. The exotic animal practitioner needs to be fully aware of these limitations and implications and be willing to perform a thorough literature search for already established information when contemplating the use of a novel drug in exotic animal species.
Careful monitoring is essential to performing anesthesia safely in small exotic animals. Because there are no flawless electronic patient monitors, no device can replace the anesthetist. Numerous monitoring devices are available to assist the anesthetist. Unfortunately, many of the available monitoring tools and techniques do not adapt well to small exotic species, and their inability to adapt emphasizes the need for careful subjective monitoring of anesthetic depth and brevity of the anesthetic episode. The utility of available monitoring tools and techniques for small exotic animals is reviewed.
A wide range of soft-tissue surgery techniques are now conducted routinely on rabbits and rodents. Preoperative assessment with intraoperative and postoperative monitoring are vitally important to the success of the surgery. General surgical principles as they relate to small mammal surgery are discussed. The more common surgical procedures are described, often with more than 1 method, for rabbit and rodent species. Surgeries described include ovariohysterectomy, castration, ovariectomy, cesarian section, enucleation, gastrointestinal surgery, and cystotomy.
Antagonism of ketamine-xylazine (85 mg of ketamine/kg of body weight and 15 mg of xylazine/kg, IM) anesthesia in rats by yohimbine (YOH; 1, 5, 10, and 20 mg/kg, IP), tolazoline (TOL; 10, 20, or 50 mg/kg, IP), 4-aminopyridine (4-AP; 1 or 5 mg/kg, IP), or a combination of yohimbine and 4-aminopyridine (YOH:4-AP, 1 mg/kg:1 mg/kg or 5 mg/kg:1 mg/kg, IP) was studied. All dosages of YOH, TOL, 4-AP, and YOH:4-AP reduced the time to appearance of corneal and pedal reflexes. Only TOL was effective in reducing time to appearance of the crawl reflex and recovery time. Yohimbine, 4-AP, YOH:4-AP, and TOL were effective in reversing respiratory depression caused by ketamine-xylazine anesthesia, but anesthetic-induced hypothermia was not antagonized. When given to non-anesthetized rats, the antagonists had little influence on respiratory rate, but all antagonists caused significant (P less than 0.05) reduction in core body temperature for at least 90 minutes. When YOH was used as an anesthetic antagonist at dosage of 20 mg/kg, 20% mortality was observed and was attributable to acute respiratory arrest. The use of 4-AP and YOH:4-AP at the dosages studied induced moderate to severe muscular tremors. In conclusion, TOL at dosage of 20 mg/kg given IP, appears to be an appropriate antagonist for ketamine-xylazine anesthesia in rats.
Gerbils have been neglected in published reports on anesthesia. This study compared several dosages of Telazol used for anesthesia in the gerbil. Each group of animals injected with Telazol was evaluated for onset and duration of anesthesia and analgesia. Results showed Telazol to be a safe anesthetic and when dosed at 60 mg/kg to be suitable for major surgical procedures. Lower dosages of Telazol, in contrast, provided immobility and analgesia suitable for less nocioceptive and noninvasive experimental manipulations. Dosages of Telazol required for surgical depth of analgesia and anesthesia were accompanied by a prolonged recovery time. Gerbils should be monitored closely to insure a safe recovery when using the higher dosages.
This article attempts to cover the more specific pruritic problems encountered in rabbits, rodents, and ferrets. There are certainly other causes of pruritus in these animals. Dermatophytes in guinea pigs are not reported to be pruritic, but because they are pruritic in other species, they should be considered in a differential diagnosis. A cryptococcal dermatitis in a guinea pig that was pruritic has been reported. Although mites were not seen on scraping, the animal was treated for sarcoptid mites and apparently the pruritus lessened. Because the cryptococcis was still present, it is questionable whether it was causing the pruritus. Pruritic ulcerative dermatitis over the back and shoulders has been seen in some lines of rats. Staphylococcus aureus was cultured from many of the lesions. Clipping the toenails on the feet helped lessen the severity of the lesions. Syphacia spp. have been reported in rats, gerbils, and hamsters and should be considered if there is perineal pruritus. MOBS, or "move over buddy syndrome," is seen especially in mice and may be seen in hamsters, gerbils, and rats that are overcrowded or stressed. The lesions are actually bite wounds that have been inflicted around the tail base and the perineum and on the tail, but these wounds can be mistaken for self-inflicted trauma from pruritus. All of the recommended treatments are extralabel, and clients should be informed of this. I have observed a guinea pig become lethargic and anorexic after only one application of a flea powder approved for use in cats. Brushing most of the powder off and offering dandelion greens to stimulate appetite helped. The second dusting was done with the same flea powder diluted with baby powder. Whenever these animals are dipped, it is important to let them dry in a warm, draft-free area. Again, it is important to be aware that the ratio of surface area to body weight is much higher in these small animals than in the species routinely seen in veterinary practice especially to prevent toxicoses from topically applied medications and iatrogenic hypothermia or hyperthermia.
The combination of ketamine-xylazine was assessed as a surgical anaesthetic in Djungarian hamsters acclimatized to both long (16 h light: 8 h dark) and short (8 h light: 16 h dark) photoperiods. It was concluded that 50 mg/kg of ketamine with 10 mg/kg of xylazine or 100 mg/kg of ketamine with 5-10 mg/kg of xylazine when given together by intraperitoneal injection was a satisfactory general anaesthetic. Two hundred mg/kg of ketamine with 10 mg/kg xylazine caused death in 13 of 24 animals. There were no clinically significant effects on depth of anaesthesia due to photoperiod.
Liponyssoides sanguineus, principal vector of Rickettsia akari, infested mongolian gerbils (Meriones unguiculatus) mice (Mus musculus) and laboratory-reared egyptian gerbils (Meriones libycus). Only a few mites were present on each animal and no manifestations of disease were observed. Numerous mites were present in the bedding.
Small mammals receive analgesics much less frequently than more familiar species such as dogs and cats. This is probably related to the greater difficulty of recognizing pain in these species, and the uncertainty as to the most appropriate analgesic regimen to implement when the presence of pain is suspected. However, the same principles of pain assessment and analgesic use that are applied when dealing with other companion animals can be used to manage pain effectively in small mammals. All of the commonly used analgesic agents can be used safely and effectively in small mammals, although the size of many of these animals limits the use of techniques such as epidural administration or transdermal drug delivery systems. As with other species, it is important to integrate an analgesic regimen with the overall scheme of perioperative care, and to try to implement preemptive and multi-modal analgesic therapy.
Ferrets, rabbits, and rodents are increasingly being presented to veterinarians for evaluation and treatment. The owners of these animals expect high-level medical and surgical care. Consequently, veterinarians are more often required to provide intensive anesthetic management of these animals. The variability of anesthetic agents used and patient responses are addressed. The consequences of size for anesthetic management are discussed. Successful small mammal anesthesia requires following general anesthetic principles, awareness of limitations, and maintenance of high standards of care.
The intrinsic physiologic and anatomic differences between small exotic mammals and the species that are more familiar to veterinary practitioners (i.e., dogs and cats) are substantial. This discussion is limited to rabbits, mice and rats (murid rodents), hamsters and gerbils (cricetid rodents), and guinea pigs and chinchillas (hystricomorph rodents). In addition to their anatomic and physiologic differences, differences in behaviors, such as their reaction to stress and pain, exist. Preoperative and postoperative care, basic surgical techniques unique to these species, and useful materials are discussed.
Because many exotic pets are so small, the instrumentation and equipment used for surgery are different from in larger animals. Magnification greatly improves the surgeon's ability to accomplish surgeries in small patients and helps to provide hemostasis because small amounts of blood are significant in these tiny patients. Microsurgical instrumentation is important to allow for proper tissue handling and suture placement. Various other considerations, instrumentation, and equipment are useful when performing surgery on small exotic pets.
Practitioners may be called on to treat rodents with respiratory diseases or to advise clients concerning the care of these rodents. Respiratory diseases of mice, rats, guinea pigs, and Syrian hamsters are well known because of the use of these species in research, whereas few or no reports of respiratory disease in rodents of other species exist. Features of the respiratory diseases of these four commonly encountered species are reviewed, including causes; clinical signs; diagnostic procedures; preventive measures; and, where appropriate, therapies.
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.
The clinical examination of small rodents is like that of more conventional pets in that the same systematic approach is used to arrive at a problem list. The difference with these species is that their diminutive size, high metabolic rate, and lack of patience may be problematic for the clinician. With continued practice and patience, veterinarians can begin to feel comfortable in adding small rodents to the growing components of their practices.
In emergency situations, veterinarians often are presented with critical patients of any species. The principles for critical care in traditional species such as the dog or cat can be applied to other small mammals. Although there are many unique aspects of the anatomy and physiology of different species, emergency care of small mammals can be instituted with the adaptation of products found in many general practices. Careful assessment of the patient, prioritization of the injuries, and rapid intervention can be life saving in any species.
Small exotic mammals and rodents are becoming popular pets in the United States. Like most other exotics, the popularity of these animals has vastly preceded the accumulation of practical husbandry and veterinary information available about them. Several dermatologic conditions have been described in most rodents and small exotic mammals; however, the practitioner can assume that more exist that have not yet been diagnosed or documented. It is not unreasonable to assume that rodents and small exotic mammals could be affected by many of the same dermatologic conditions well described in other animals. Veterinarians are encouraged always to apply the same diagnostic protocols used to work up skin problems in dogs and cats when presented with an exotic pet with a dermatologic disease.
Although fungal disease is uncommon in rodents, dermatophytosis is the most common mycosis seen in clinical practice. T. mentagrophytes is the most common etiologic agent, and the guinea pig is the most common species affected, although there are reports in all pet and laboratory rodent species except the gerbil. Despite the low incidence of clinical disease, rodents are common asymptomatic carriers of dermatophytes, and ringworm is the most common zoonotic disease transmitted from rodents to people.
Most viral infections in small mammals are transient and rarely produce clinical signs. When clinical signs do appear, they are often of a multifactorial etiology such as respiratory infection with Sendai virus and the bacteria M. pulmonis in rodents. Diagnosis is generally made based on clinical signs, while therapy involves treatment for concurrent bacterial infections and supportive care. Small mammals may carry zoonotic viruses such as LCMV, but natural infections are uncommon. Viral diseases are rare (or largely unknown) for hedgehogs, chinchillas, and prairie dogs, while no known naturally occurring, clinically relevant viral diseases exist for gerbils and sugar gliders. This article is intended to aid the clinician in identifying viral infections in small mammals and to help determine the significance each virus has during clinical disease.