Clinical Update on Diagnosis and Management of Disorders of the Digestive System of Reptiles

The diagnosis and treatment of digestive system disorders in reptile species continues to provide challenges owing to the differences in anatomy and physiology in this diverse group of animals. Continued research efforts into diagnostic techniques, in particular imaging (e.g., contrast radiography and ultrasonography), of gastrointestinal tract have resulted in clinical advancements for practicing veterinarians. The aim of this article is to provide veterinarians up-to-date and clinically relevant summaries on the diagnosis and therapy of digestive system disorders of reptiles commonly maintained as companion animals.     

Clinical Anesthesia and Analgesia in Fish

Fish have become a popular experimental model and companion animal, and are also farmed and caught for food. Thus, surgical and invasive procedures in this animal group are common, and this review will focus on the anesthesia and analgesia of fish. A variety of anesthetic agents are commonly applied to fish via immersion. Correct dosing can result in effective anesthesia for acute procedures as well as loss of consciousness for surgical interventions. Dose and anesthetic agent vary between species of fish and are further confounded by a variety of physiological parameters (e.g., body weight, physiological stress) as well as environmental conditions (e.g., water temperature). Combination anesthesia, where 2 anesthetic agents are used, has been effective for fish but is not routinely used because of a lack of experimental validation. Analgesia is a relatively underexplored issue in regards to fish medicine. However, recent studies have investigated opioid agents, nonsteroidal antiinflammatory drugs, and local anesthetics to determine their efficacy in minimizing pain and discomfort. The opioid morphine and the local anesthetic lidocaine do have significant effectiveness in reducing pain-related responses in rainbow trout (Oncorhynchus mykiss). Studies aimed at developing reliable analgesic protocols should explore a wide range of analgesic drug classes in several fish species.     

Venomous Snake Restraint and Handling

Venomous snakes may be maintained as captive animals and are commonly exhibited in both zoos and private zoological collections. Veterinarians who treat reptile species may be asked to provide medical care to venomous snakes. The addition of venomous snakes to the practice can be exciting and rewarding. Training and experience handling venomous snakes are required before treating these animals in a veterinary practice. Both training and experience with handling venomous snakes are important not only to protect hospital personnel but the owner and patient as well. Veterinarians who wish to provide care for venomous snakes need to be familiar with the many tools used to make restraint and handling venomous animals as safe as possible.     

Clinical Analgesia in Reptiles

Reptile pain and analgesia is only beginning to be understood in veterinary research and clinical medicine. The diversity of the class Reptilia also makes it difficult to extrapolate analgesic efficacy across species. Many veterinary clinicians argue that the administration of analgesic medication is risky to the patient and may mask behavioral signs of pain, which are considered evolutionarily adaptive for survival. However, veterinarians have an ethical obligation to treat painful conditions in all animals, including reptiles, because effective pain management reduces stress-induced disruption to homeostatic mechanisms and also decreases morbidity and mortality associated with trauma or surgery. Nevertheless, several obstacles limit successful analgesic use, including subjectivity of pain assessment, inadequate knowledge regarding analgesic efficacy across species, pharmacokinetics of analgesic drugs, and the unknown relationship between risks and benefits for this class of drugs. The objective of this review is to provide a current perspective on the practical application of analgesic medication in commonly maintained pet reptile species.     

Reptile respiratory medicine.

Respiratory tract disease is commonly diagnosed in captive collections of reptiles and associated with high morbidity and mortality. Improper environmental conditions are often contributing factors for the development of respiratory disease in reptiles. A detailed knowledge of the unique reptilian respiratory morphology and function is essential to successfully diagnose and treat respiratory disease. A variety of noninfectious and infectious causes have been identified in the etiology of reptile respiratory disease. Knowledge of the pathophysiology of reptilian diseases is increasing, and with the availability of new therapeutic agents and advanced diagnostic techniques, the diagnosis and treatment of reptile respiratory tract disease has become more successful.     

The immune response to anesthesia: Part 1

ObjectiveTo review the immune response to anesthesia including mechanical ventilation, inhaled anesthetic gases, and injectable anesthetics and sedatives.Study designReview.Methods and databasesMultiple literature searches were performed using PubMed and Google Scholar from spring 2012 through fall 2013. Relevant anesthetic and immune terms were used to search databases without year published or species constraints. The online database for Veterinary Anaesthesia and Analgesia and the Journal of Veterinary Emergency and Critical Care were searched by issue starting in 2000 for relevant articles.ConclusionRecent research data indicate that commonly used volatile anesthetic agents, such as isoflurane and sevoflurane, may have a protective effect on vital organs. With the lung as the target organ, protection using an appropriate anesthetic protocol may be possible during direct pulmonary insults, including mechanical ventilation, and during systemic disease processes, such as endotoxemia, generalized sepsis, and ischemia-reperfusion injury.     

Pharmacokinetics of ketoprofen in the green iguana (Iguana iguana) following single intravenous and intramuscular injections.

The nonsteroidal antiinflammatory drug ketoprofen (KTP) is a commonly used antiinflammatory and analgesic agent in reptile medicine, but no studies documenting its pharmacokinetics in this species have been published. Ketoprofen was administered as a racemic mixture to green iguanas (Iguana iguana) intravenously (i.v.) and intramuscularly (i.m.) at 2 mg/kg. Pharmacokinetic analyses were performed and indicated that ketoprofen in iguanas administered by the intravenous route has a classical two-compartmental distribution pattern, a slow clearance (67 ml/ kg/hr) and a long terminal half-life (31 hr) compared to ketoprofen studies reported in mammals. When delivered by the intramuscular route, bioavailability was 78%. These data indicate the daily dosing that is generally recommended for reptile patients, as an extrapolation from mammalian data, may be more frequent than necessary.     

Evaluation of the use of anesthesia and analgesia in reptiles

OBJECTIVE: To determine anesthetic techniques and the drugs used to provide anesthesia and analgesia to reptiles. DESIGN: Mail-out questionnaire. SAMPLE POPULATION: 367 members of the Association of Reptile and Amphibian Veterinarians. PROCEDURE: 1,091 members listed in the 2002 directory of the Association of Reptile and Amphibian Veterinarians were asked to complete a questionnaire regarding anesthesia and analgesia. RESULTS: 367 of 1,091 (33.6%) individuals completed the questionnaire; 88.8% used inhalants (particularly isoflurane) for anesthesia, and ketamine, propofol, and butorphanol were the most commonly used injectable agents. Intubation, fluids, and having a dedicated anesthetist were most commonly used for patient support, and pulse oximetry and Doppler ultrasonography were most commonly used for monitoring. Respiratory depression, difficulty monitoring anesthetic depth, prolonged recovery, and hypothermia were the most frequent complications. Nearly all respondents believed that reptiles feel pain, but analgesics were used infrequently for many reasons. CONCLUSIONS AND CLINICAL RELEVANCE: Providing anesthesia in reptiles is difficult, especially regarding anesthetic depth and vital parameters, and methods of support are used less frequently than in domestic species. Provision of analgesia is uncommon. Research regarding pain and its assessment, response to analgesics, and drug pharmacokinetics is needed. Dissemination of this information to practitioners needs to be improved for enhancement of the standard of care for reptiles.     

江西凌云山自然保护区两栖爬行动物多样性调查与区系分析

为掌握江西宁都凌云山省级自然保护区野生动物资源现状,促进自然保护区的有效管理和建设,作者于2012年至2013年多次对该保护区两栖爬行动物资源进行了实地考察。调查结果显示,凌云山保护区现已记录两栖爬行动物52种,隶属于2目13科37属。其中,两栖动物19种,隶属于1目6科14属,占江西省39种两栖动物的48. 7%;爬行动物33种,隶属于1目7科23属,占江西省80种的41. 3%。凌云山位于动物地理分布区中的东洋区系区的偏北位置,向古北区靠近,古北区的种类也会扩散到这一地区,成为东洋区、古北区的共有种。因此在两栖爬行种类组成上以东洋区的种类为主,具有多样性较为丰富的特点。最后对凌云山保护区的保护与管理工作提出了加大对当地群众的宣传和教育工作等建议。     

Disposition of anesthetic and anesthetic-related agents in ruminants

Many factors may influence the actions and fates of anesthetic and anesthetic-related agents in ruminant animals. These considerations need to be taken into account when these drugs are employed clinically. Some of the major principles governing the disposition of CNS-active drugs are reviewed, with special emphasis on the uniqueness of ruminant animals. General pharmacokinetic considerations are also covered as a preamble to a commentary on the kinetic characteristics of anesthetic and anesthetic-related agents that are commonly used in domesticated ruminants.     

Reptile anesthesia.

Successful reptile anesthesia requires patience, planning, and understanding of normal anatomy and physiology in health and disease. Reptiles make good anesthetic patients because of their physiologic resilience. New drugs that are not only safe and efficacious, but also result in relatively short recovery times, have greatly enhanced the design of anesthetic regimens. Further studies are required to quantitatively evaluate the physiologic effects of drugs used and validate available monitoring modalities for use in a wide variety of reptiles.     

Anesthesia and Analgesia in Rabbits and Rodents

Rabbits and rodents are popular pets and are often presented to veterinarians for evaluation and medical treatment. Anesthesia in exotic pets is required for many diagnostic and surgical procedures and is associated with a higher perioperative risk in rabbits and rodents when compared with dogs and cats. Inhalation anesthetic agents are commonly used as the sole source of anesthesia in small rodents, whereas injectable agents in combination with inhalation anesthesia are often used for rabbits and larger rodents. Analgesia is an important component of exotic pet medicine. Although it may be difficult to recognize signs of pain in companion exotic mammals, adequate pain management should always be provided. Opioid and nonsteroidal antiinflammatory drugs are the analgesic medications of choice, but others should be considered (e.g., local anesthetic agents). This article provides an update of the current literature regarding anesthesia and analgesia in rabbits and rodents.     

Equipment for inhalation anesthesia

Inhalation anesthesia has three requirements: delivery of oxygen, delivery of an appropriate concentration of a volatile anesthetic agent, and removal of carbon dioxide. Halothane and isoflurane are the most commonly used anesthetic agents. They are usually delivered with a semiclosed circle system using an out-of-the-circuit vaporizer. Carbon dioxide is eliminated by chemical absorption and by flow of excess oxygen and waste anesthetic agent through the pop-off valve. These gases should be scavenged to prevent room contamination. A variety of ancillary equipment is available to assist the anesthetist during the procedure.     

Comparison of sevoflurane and isoflurane in domestic ferrets (Mustela putorius furo)

Isoflurane anesthesia is commonly used in ferrets for routine examinations and diagnostics. Sevoflurane is now being used as well, but there have been no studies to date directly comparing these agents in domestic ferrets. A prospective study was designed to evaluate the quality and speed of anesthetic induction and recovery using isoflurane and sevoflurane in ferrets. In addition effects on heart rate, blood pressure and packed cell volume were also recorded. No significant differences were noted between anesthetic agents.     

Invertebrates and invertebrate disease; an introduction for the veterinary surgeon

The veterinary surgeon has a role to play in the care of invertebrates, many of which are kept as pets and for educational and scientific purposes. Some of those species commonly maintained in captivity are listed and their accommodation, feeding, handling and restraint are outlined. Invertebrate diseases may be due to (or associated with) infectious agents, parasites, environmental changes, trauma, faulty nutrition or poisons and each of these is discussed briefly. Particular attention is drawn to the need for good management and preventive measures, especially hygiene.     

Future directions in reptile medical education

Reptile medicine has emerged as a specialty area within the broader field of zoological medicine. It encompasses the medical needs of approximately 7,500 vertebrate species. This vertebrate class is highly diversified, having biological and medical peculiarities that differ both between and within major groups. Historically, veterinarians who have become recognized specialists with reptiles have had limited formal training in their medical management. The pet reptile trade is a multi-million-dollar business, and the popularity of reptiles as pets has resulted in a need for more veterinarians with training in their medical management. While few private practices have high volumes of reptile cases, many small-animal practices will have the opportunity to see a significant number of reptiles on an annual basis. Most practitioners with reptile medical expertise have merged their experiences as reptile pet owners with the principles of veterinary medicine taught in veterinary college. Several North American veterinary colleges have reptile medicine courses, and most have didactic and clinical courses in exotic and zoo animal medicine that include lectures and practical experience. Most accredited zoological medicine residency training programs include training in reptile medicine. The case load and interest in reptile medicine will probably never be sufficient to lead the average veterinary college to develop much more than what is currently offered. Consequently, those few colleges having more extensive course offerings, both didactic and clinical, will serve as educational centers for this discipline. Future Web-based teaching programs in reptile medicine will allow students nationally and internationally to have access to instructional material that can be continually updated.     

Anesthesia in the Llama

Anesthesia for llamas is similar to other domestic species, although adjustments in technique are required to allow for species variations. Xylazine (0.4-0.6 mg/kg) is well tolerated for sedation. The thiobarbiturates (8-10 mg/kg), ketamine (2.5-5.0 mg/kg), or combinations of guaifenesin and thiobarbiturates or guaifenesin and ketamine (to effect) can be used for induction of anesthesia. In juvenile or debilitated animals, anesthesia can be induced with halothane or isoflurane administered by mask. After tracheal intubation, anesthesia can be maintained with the inhalation agents, usually halothane or isoflurane. Supportive therapy and many anesthetic monitoring techniques used in domestic animals can be used in llamas. While under marginal planes of anesthesia, llamas can have more active physiologic responses to pain, including bradycardia and vasoconstriction, than domestic animals. Llamas are more prone to airway obstruction after tracheal extubation than domestic ruminants but otherwise recover as well from general anesthesia as domestic ruminants.     

Advantages of and guidelines for using neuromuscular blocking agents.

Neuromuscular blocking agents, although not commonly used in veterinary practice, should be considered when muscle relaxation is needed to facilitate surgical exposure and minimize tissue trauma. These drugs should be administered only once respiration has been controlled and anesthetic agents have been administered to induce unconsciousness and analgesia. Following administration of neuromuscular blocking drugs, neuromuscular and cardiovascular function must be monitored.     

Sedation and anesthesia of pet rabbits

Pet rabbits frequently become stressed when handled and may require sedation or chemical immobilization for procedures such as blood collection, IV catheter placement, radiography, deep ear cleaning, and dentistry. Common surgical procedures requiring general anesthesia include spay, castration, gastrotomy, cystotomy, and orthopedic procedures. Rabbits may be difficult to safely sedate or anesthetize. Individual rabbits may have varying sensitivity to the depressant effects of anesthetics. The apparent sensitivity of the rabbit's respiratory center to anesthetic drugs and the narrow range between anesthetic and toxic doses in this species add to the unpredictable character of rabbit anesthesia. Furthermore, mortality following anesthesia and surgery in sick rabbits is common. Strategically, safe anesthesia of rabbits must include the planning of procedures so that anesthetic time is minimized. Clinicians must be on guard for individual variation in response to drugs. Minimizing the use of cardiovascular depressant agents, use of agents with a high therapeutic index, and careful titration of doses to effect, along with thorough cardiorespiratory monitoring, will permit attainment of appropriate anesthetic depth with the widest margin of safety. This article presents several injectable and inhalant anesthetic protocols that may assist in effective management of many types of rabbit patient.