Effects of Lupron and surgical castration on fecal androgen metabolite concentrations and intermale aggression in capybaras (Hydrochoerus hydrochaeris).

To curb agonistic interactions in a bachelor group of three male capybaras (Hydrochoerus hydrochaeris), a single dose of leuprolide acetate (Lupron®) was used in an attempt to chemically sterilize the males. Concurrently, fecal androgen metabolite (FAM) concentrations were quantified via enzyme immunoassay to monitor changes in testosterone production after injection of the gonadotropin-releasing hormone agonist. When Lupron proved ineffective in suppressing intraspecific aggression, surgical castration was performed on two males, with continued noninvasive endocrine monitoring. In all three capybaras, FAM concentrations increased initially as a result of the luteinizing hormone surge, but then decreased significantly following chemical sterilization. Surgical castration resulted in further, persistent declines in FAM concentrations in two males, while the third, intact male demonstrated a rise in FAM to pre-Lupron concentrations at 8.5 and 9.5-month postadministration. Despite successful suppression of sperm and testosterone production, intermale aggression continued, ultimately necessitating separation of the animals and transfer to other holding institutions. Under this set of conditions, a single Lupron dose was inadequate for suppressing intraspecific aggression in a group of three males with a pre-established history of aggression.

A novel approach to scavenging anesthetic gases in rodent surgery.

Laboratory animal procedures using gas anesthetics may amass elevated waste gas concentrations in operating rooms if controls are not implemented for capturing and removing the vapors. Area sampling using an infrared analyzer indicated isoflurane concentrations likely to exceed occupational exposure guidelines. Our study showed environmental concentrations of oxygen as high as 40% and isoflurane concentrations >100 ppm when no controls or merely passive controls were utilized. These extraneous isoflurane emissions were determined to be originating from the pre-procedural induction process as well as the gas delivery nose cone. A novel waste gas collection cylinder was designed to enclose the gas delivery nose cone and animal head during the administration of anesthetic gases. The vented cylinder utilized a house vacuum to remove the waste anesthetic gases from the surgical field. A commercially available induction chamber designed to be actively and externally exhausted was used to lower concentrations during the induction process. With implementation of local exhaust ventilation controls, waste anesthetic gas concentrations decreased to below recommended occupational exposure levels. In vitro (sham) testing compared favorably to in vivo measurements validating the reduction capability of active ventilation during rodent anesthetic administration. In vivo isoflurane reductions for the induction chamber emissions, the operating room, and the surgeon's breathing zone were 95%, 60%, and 53%, respectively. The same measurements for an in vitro procedure were 98%, 84%, and 87%, respectively.

[Fractures and luxations in small mammals]. / Frakturen und Luxationen beim Kleinsäuger.

Most traumata in small mammals occur at home. Diagnosis and therapy can be compared with that in the dog and cat, but species-specific differences have to be considered. For fracture treatment a butterfly-cast can be sufficient for stabilization in special cases. In most cases satisfying results can be obtained with a "tie-in-fixator" treatment. Dislocations of the elbow joint are treated by reduction or stabilization through suture techniques or temporary arthrodesis.

Mandibular incisor apicoectomy in a Canadian Beaver.

A 52-month-old Canadian beaver was presented for treatment of lip trauma resulting from overgrowth of the right mandibular incisor tooth following earlier loss of the right maxillary incisor tooth. Extraction of the affected tooth was considered, but rejected due to the length of the embedded portion of rodent mandibular incisor teeth. The lip injury was managed by crown reduction (odontoplasty) of the overgrowing incisor tooth pending a more permanent treatment plan. A 2-cm apicoectomy of the right mandibular incisor tooth was performed to arrest growth of the tooth when the beaver was 82-months-old. The remainder of the tooth continued to erupt and was completely expelled during a 9-month period with one additional odontoplasty being required. The beaver continued to feed normally with just the left maxillary and mandibular incisor teeth until its death at 118-months, with odontoplasty performed twice on the remaining incisor teeth during the 30-months following exfoliation.

A program for simulated rodent surgical training.

For the inexperienced individual, learning surgical techniques can be taxing. The authors developed a rodent surgery dry lab training program to assist educational and research institutions in providing low-stress training for basic surgical techniques using handmade, cost-effective simulation models. The program not only helps students develop essential skills in basic surgery, but also fulfills the mandate of the 3Rs by allowing students to repeatedly practice and refine their skills on models rather than live animals. This type of training is a valuable tool in bridging the gap between computer training and training with live animals.

Small Mammals: Common Surgical Procedures of Rodents, Ferrets, Hedgehogs, and Sugar Gliders.

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.

A case of maloccluded incisor teeth in a beaver: castor canadensis.

A three-year-old female beaver (Castor canadensis) was referred to the Veterinary Teaching Hospital of Chungbuk National University. It had been raised in the Cheong-ju zoo and had a history of malocclusion caused by improper feeding. General anesthesia was induced, and preoperative intraoral dental radiographs of the rostal maxillary and mandibular dentition were taken and lateral and ventrodorsal extraoral radiographs of the cheek teeth were also taken. The radiographs were negative for apical pathology and revealed a normal appearance of the cheek teeth. The lesion was likely to be related to the excessive length of the maxillary and mandibular incisors. Odontoplasty was performed to reduce overgrowth of the crowns of the incisors. Sequential transverse sections were removed until the crown was reduced by approximately its original length. The pulp chamber was not approached during the operation, as confirmed by postoperative intraoral radiographic evaluation of the incisors. Recovery from anesthesia was uneventful and the beaver returned to normal masticatory activities immediately after the operation.

A hypothermic miniaturized stereotaxic instrument for surgery in newborn rats.

We describe a simple, scaled-down instrument which enables accurate, reproducible stereotaxic placements into specific sites in the brain of the newborn rat. The instrument is specially designed for the administration of long-term hypothermia, yet permits the use of alternative methods of anesthesia. The design of the head-stabilizing mechanism allows head positioning to be finely adjusted to achieve precise horizontal and vertical zero planes. This adaptability also allows the device to accommodate a large range of animal sizes and levels of maturity. Furthermore, the apparatus can be fitted onto a conventional adult stereotaxic frame or used by itself in combination with a free-standing manipulator. As a model preparation, we describe a procedure for stereotaxic surgery in the post-natal day (P1) rat. The versatility of the instrument has permitted successful stereotaxic surgery in adolescent as well as neonatal rats, newborn and adult mice, and newborn hamsters.

Midazolam and fentanyl-fluanisone: assessment of anaesthetic effects in laboratory rodents and rabbits.

The anaesthetic effects of a combination of midazolam, a water-soluble benzodiazepine, and fentanyl-fluanisone were assessed in laboratory rodents and rabbits. This combination of drugs produced good surgical anaesthesia in all of the species investigated. An important advantage of the combination was that it could be administered as a single intraperitoneal injection.

Small rodents.

Although rodent pets constitute only a small percentage of pets seen in practice, owners of rodents are as dedicated to those pets as are other owners to the more common dogs and cats. Rodents make excellent pets, with low space, feeding, and economic requirements. Medical care for rodents is based primarily on gross clinical signs, because most standard diagnostic tests done in larger animals cannot be done in small rodents. Even with that disadvantage, however, specific diagnosis of most rodent diseases is possible, and several of those diseases can be treated successfully. Among the common diseases of small rodents are ascariasis, pyoderma, incisor malocclusion and overgrowth, neoplasia and abcessation, nephrosis and amyloidosis, respiratory infection, enteritis, and neurologic disorders. Most drugs used in rodents, including anesthetics, are the same as those used in other species, with the exception of several drugs contraindicated in hamsters.

The use of surgical lasers in exotic and avian practice.

Use of diode laser energy with fiberoptic endoscopic delivery in exotic animal and avian practice offers a minimally invasive method for performing specific surgical procedures. Trauma and blood loss are minimized, but the absorption characteristics of the diode laser wavelengths (805/980 nm) must be considered to avoid potential postoperative complications due to collateral photothermal coagulative necrosis.

Alcohol as a disinfectant for aseptic surgery of rodents: crossing the thin blue line?

Recently, the use of alcohol (i.e., ethanol or isopropanol) has been discouraged as disinfectants for survival surgical procedures for rats and mice because of perceptions of inadequacy of killing of bacterial spores and lack of efficacy in the presence of organic debris. However, spore-forming bacteria are a minor (essentially nonexistent) threat for causing postoperative infections in rats and mice (but not necessarily hamsters, guinea pigs, or other rodents), and organic debris, with appropriate effort, can be removed from soiled instruments by using physical scrubbing. Although the metal-corrosive properties of alcohol and the lengthy times needed for adequate disinfection are drawbacks, there are essentially no microbiologically relevant reasons to discourage disinfection by ethanol or isopropanol in rat and mouse surgery.

Surgical sterilization in small mammals. Spay and castration.

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.

Nonreproductive surgery in small mammals.

The sophistication of soft-tissue surgery techniques in small mammals is increasing rapidly. Exotic animal practitioners must be familiar with the diseases, conditions, and anatomic variations of each small-mammal species. The small size of these patients should not preclude the use of technologic advances available for other small animals. Despite these challenges, successful resolution of surgical problems in small exotic mammals is not only possible but also should be the expected result of veterinarians' efforts in such cases.

Principles of rodent surgery for the new surgeon.

For both scientific and animal welfare reasons, training in basic surgical concepts and techniques should be undertaken before ever seeking to perform surgery on a rodent. Students, post-doctoral scholars, and others interested in performing surgery on rodents as part of a research protocol may not have had formal surgical training as part of their required coursework. Surgery itself is a technical skill, and one that will improve with practice. The principles of aseptic technique, however, often remain unexplained or untaught. For most new surgeons, this vital information is presented in piecemeal fashion or learned on the job, neither of which is ideal. It may also make learning how to perform a particular surgery difficult, as the new surgeon is learning both a surgical technique and the principles of asepsis at the same time. This article summarizes and makes recommendations for basic surgical skills and techniques necessary for successful rodent surgery. This article is designed to supplement hands-on training by the user's institution.

Development and implementation of multimedia content for an electronic learning course on rodent surgery.

The development of new rodent models of human disease and advances in surgical equipment and technologies have increased the demand for expertise in rodent surgery. Because of the limited availability of rodent surgical training courses, electronic (e-) learning is presented as an alternative to in-person education and as a means to hone the expertise of current surgeons in biomedical research, similar to e-learning applications for human surgery training. Translating this model to the biomedical research field provides participants with an opportunity to train themselves on rodent surgical techniques prior to operating on live models. An e-learning rodent surgery course was incorporated into a training class of undergraduate (n = 39) and graduate (n = 12) laboratory animal students, and a portion of the course was presented to laboratory animal professionals (n = 15). The effectiveness of the method was evaluated using written examination and postcourse surveys. The exam data demonstrated that the e-learning course transferred knowledge comparable to a lecture course on surgery that was presented in-person. Students responded favorably to videos, step-by-step photographs of surgical procedures, and the ready accessibility of the course. Critiques included the need to improve video resolution and quality of the voice-overs. These results support the continued development and implementation of electronic rodent surgical technique courses for use in laboratory animal and biomedical research communities.