- Reproductive Postoperative Care In Laboratory Animals Pdf File
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6Control of Stress and DistressThis chapter provides guidance on the control of stress and distress in laboratory animals pharmacologically—presenting information on the clinical uses, effects, and dosages of four groups of drugs (see Tables and )—and nonpharmacologically.Distress in laboratory animals is usually unnecessary and unwanted. Despite an inability to define or measure distress in laboratory animals precisely, distress is used to describe a point at which adaptation to a stressor (environmental, psychologic, or physiologic) is not sufficient to maintain equilibrium and maladaptive behaviors appear. Users of animals are responsible for the prevention, alleviation, or elimination of distress. The possibility of distress is best considered before laboratory animals are used experimentally; that is, careful consideration should be given during experimental design to means by which non-pain-induced distress can be avoided (ideally) or minimized. Stressors that can lead to distress should be understood and identified (see ).
If one is to deal adequately with distress in laboratory animals, one must be able to recognize it (see ). That requires that species-typical behaviors associated with well-being be understood and that the normal behavior and appearance of the animals being used be known. Distress can be subtle; so too can its influence on experimental outcomes.Distress results from stress to which animals cannot adequately adapt.
The stressor can be an external or internal event that causes physical or psychologic trauma. For its purpose, the committee identified these stressors as pain-induced and environmentally induced. Nominal stress is usually cause for alarm only if an animal is unable to adapt properly to it. When that occurs and distress results. Treatment should begin with an identification of the underlying cause.
The principles of postoperative care Reasons for vital signs monitoring Considerations for transferring postoperative patients Monitoring, assessment and observation skills are essential in postoperative care. Nurses can support patients recovering from surgery and identify complications Principles of monitoring postoperative patients. Clinical Research Laboratory and Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology. Animal Welfare Act and the Guide for the Care and Use of Laboratory Animals.19 Surgery After a 2-week quarantine period, the rabbits. The usual postoperative care was given.
Pain-induced stress should then be alleviated by removal of the cause of the pain or through administration of analgesics, but non-pain-induced stress is seldom amenable to pharmacologic treatment alone. Rather, environmental stressors or factors should be addressed. The use of tranquilizers can sometimes help an animal adapt to necessary changes in its environment, but is seldom sufficient in itself.This report places considerable emphasis on the importance of recognizing maladaptive behaviors resulting from stress with which an animal is unable to cope effectively as evidence of distress. Some conditions of acute stress in which an animal's behavior is normal and adaptive also suggest that intervention is warranted. Such conditions are brought on typically when an animal is strongly motivated to avoid or escape a stimulus or set of conditions.
Such behaviors, like maladaptive ones, should be interpreted as causing harm to the animal and producing unwanted variability in research data. PHARMACOLOGIC CONTROL OF STRESS AND DISTRESSThe tranquilizers and sedatives used in animals today include drugs in four groups: phenothiazines, butyrophenones, benzodiazepines, and α2-Adrenergic agonists. Phenothiazines and butyrophenones have many common properties, especially general sympatholytic activity. They used to be considered 'major' tranquilizers in human medicine; currently preferred terms are antipsychotics and neuroleptics. Benzodiazepines, once considered 'minor' tranquilizers, are now thought of as antianxiety-sedative agents. Α2-Adrenergic agonists have emerged as a very important group of drugs for tranquilizing and sedating animals. Clinical UsePhenothiazines depress many physiologic functions, decrease motor activity, produce mental calming, and increase the threshold of response to environmental stimulation.
Thus, they are useful for animal restraint. They do not produce sleep, analgesia, or anesthesia. The sedation produced by phenothiazines differs from the state produced by barbiturates and opioids, in that sedation occurs without hypnosis and the effects produced in animals can be reversed with an adequate stimulus.In animals, adequate doses produce a quieting effect that includes sedation, ataxia, an increase in the threshold of response to environmental stimuli, relaxation.
Of the nictitating membrane in some animals, and abolition of conditioned reflexes. It must be emphasized that animals under the sedation produced by tranquilizers can still react in a coordinated manner. A large animal can still kick with full force in reaction to painful stimuli, a vicious animal can still bite, and nonhuman primates can become aroused unexpectedly. The degree of sedation and inactivity produced by the tranquilizers in many instances depends on the excitability of the animal being treated. That is especially true in wild animals: the tranquilization of free-living and captive undomesticated animals might not be possible, and more potent drugs might be necessary (Graham-Jones, 1960, 1964). It is also true of vicious animals; i.e., tranquilizers might produce insufficient restraint for safe management of extremely high-strung nervous animals. In those circumstances, neuroleptanalgesia might have to be administered with a combination of a tranquilizer and an opioid.
In stallions, many phenothiazine tranquilizers cause erections and temporary or permanent prolapse of the penis. In horses, phenothiazines and butyrophenones cause involuntary and hallucinatory activity (Muir et al., 1989). Pharmacologic EffectsThe major action of the phenothiazines is antagonism of the central dopamine receptors.
In addition to their sedative properties, the phenothiazines and the related butyrophenones (e.g., droperidol) produce a dose-dependent decrease in motor activity. At greater doses, they produce a cataleptic state that includes rigidity, tremor, and akinesia.
The phenothiazines are also useful in some species as antiemetics. However, they have important anticholinergic, antiadrenergic, and antihistaminic effects, which often lead to undesirable or unanticipated side effects and unpredictable drug interactions.The two most commonly used phenothiazines are promazine and acetylpromazine.
They produce numerous cardiovascular effects through central and peripheral actions on the sympathetic nervous system and the CNS and direct actions on vascular and cardiovascular smooth muscle. The CNS manifestation is inhibition of centrally mediated pressor reflexes, which reduces both vascular tone and the ability to respond reflexively to alterations in the cardiovascular system. The peripheral effects are related to α2-adrenergic receptor blockade.Phenothiazines are commonly administered intravenously to animals in the standing position, especially farm animals.
The cardiovascular actions have a more rapid onset than the sedative actions, and orthostatic hypotension might explain the occasional collapse. The extent of hypotensive effects of a tranquilizer varies and depends on the state of the cardiovascular system and the sympathetic tone when the drug is administered. Fatigue, hypovolemia, excitement, and trauma can increase sympathetic tone as a part of the adaptive homeostatic process. The administration of a sympatholytic drug under those circumstances can have a profound effect (Bahga and Link, 1966). Phenothiazines lessen the ability of the cardiovascular system to compensate for changes in vascular volume, changes in position,. Pharmacologic EffectsBarbiturates and benzodiazepines share many pharmacologic actions (e.g., sedation, muscle relaxation, anticonvulsant activity, and hypnosis) because of their interaction with the GABA-chloride ionophore receptor complex. GABA (yγaminobutyric acid) is an inhibitory amino acid neurotransmitter.
Benzodiazepines appear to increase the frequency of opening of the GABA-activated chloride ion channel in nerve membranes; barbiturates enhance the binding of GABA to its receptor and increase the time that the same GABA-activated ion channel is open. Thus, barbiturates and benzodiazepines both facilitate GABA-mediated inhibitory effects on the CNS.The sedative and anxiolytic effects of the benzodiazepines are produced by doses that also produce muscle relaxation. The most commonly used benzodiazepine is diazepam. As with other drugs, there is great species variability in its effects. The effects in dogs, cats, and horses (Muir et al., 1982) are not the anxiolytic effects noted in people.
Excitement, tremors, ataxia, dysphasia, and sometimes sedation occur in animals. There is no known explanation for the major species differences noted in response to the benzodiazepines in people and animals.
Dose RecommendationsDiazepam, usually administered intravenously, is painful if given intramuscularly. In rats, it is used as an anxiolytic at 1 mg/kg to lessen stress-induced increases in blood pressure, but not changes in heart rate (Conahan and Vogel, 1986).
It can be used in ruminants for sedation at 0.2–0.5 mg/kg. In small ruminants, it is used as a premedication before ketamine anesthesia.Diazepam and midazolam are usually used with other drugs in animals.
The water solubility of midazolam, as opposed to the water insolubility of diazepam (compounded with propylene glycol), might be advantageous in some drug combinations, and midazolam is less irritating to tissues. However, it is more expensive.
Tables and list combinations of diazepam with ketamine for surgical anesthesia in several species. The preanesthetic administration of the benzodiazepines with ketamine provides good muscle relaxation and eliminates tremors produced by ketamine. 1974; Klide et al., 1975; Muir et al., 1979). In horses and ponies, xylazine given alone produces a mild degree of CNS depression.
There is some ataxia, but animals are able to stand and walk. Horses and ponies can still respond to painful stimuli, so surgical procedures should not be attempted without opioid supplementation or local analgesia. Xylazine suppresses the excitatory effects of opioids in horses when these drugs are administered together for analgesic or preanesthetic purposes.Xylazine is used extensively in other species with other drugs, especially the dissociative anesthetic ketamine.
Xylazine is not recommended for use alone to produce analgesia or anesthesia in dogs and cats, but is commonly used with ketamine. Vomiting occurs in dogs and cats after intravenous or intramuscular administration of xylazine (Klide et al., 1975), and sedative effects occur in dogs within 5–10 minutes of administration. Sedative effects include lying down, lack of response to the environment, medial rotation of the eyes, and prolapse of the nictitans. Some degree of analgesia is apparent, but xylazine is not sufficient for surgery. Spontaneous arousal can occur, and the degree of sedation is inconsistent.
Pharmacologic EffectsXylazine is a potent adrenergic receptor aα2-agonist. The major CNS effect of the aα2-agonists is a decrease in sympathetic outflow from the medullary pressor center; this accounts for the sympatholytic actions of this class of drugs. Actions of xylazine at the central aα2-agonist adrenergic receptors produce a variety of effects, including sedation, analgesia, hypotension, bradycardia, hypothermia, mydriasis, and relief of anxiety.
Cardiovascular changes in dogs and horses have been attributed to them (Klide et al., 1975; Muir et al., 1979). After intravenous administration of xylazine in dogs, heart rate and aortic flow decreased, blood pressure changes were variable, and peripheral resistance increased; there were no significant changes in blood gases and pH; atrioventricular block and nonrespiratory sinus arrhythmia were seen; and atropine did not alter the changes in cardiac rhythm. Cardiovascular changes in horses were similar, except that a transient increase in blood pressure was followed by a decrease.Other aα2-agonists have similar actions.
Detomidine has recently been introduced in this country as Dormosedan® for use in horses. Detomidine(its intravenous and intramuscular dose is 0.02–0.04 mg/kg) is more potent than xylazine and can produce more profound analgesia, sedation, and bradycardia for a longer period (Kamerling et al., 1988). NONPHARMACOLOGIC CONTROL OF STRESS AND DISTRESSThis section considers nonpharmacologic ways of preventing, minimizing, and alleviating non-pain-induced distress in laboratory animals through husbandry and management practices, socialization and handling, environmental enrichment, and experimental design. (The pharmacologic management of pain, a major stress that often leads to distress, is discussed in and will not be discussed here, except to emphasize that the use of drugs to alleviate non-pain-induced distress is generally inappropriate.) As a general rule, nonpharmacologic approaches to the prevention or minimization of distress are more desirable than pharmacologic approaches (Wolfle, 1987). HUSBANDRY AND MANAGEMENT PRACTICESControl of non-pain-induced distress centers around three of the most common causes in laboratory animals: husbandry, environment, and experimental design.Management practices in animal care and housing can contribute to such stressors as fear, anxiety, loneliness, and boredom, which, if not prevented or minimized, have the potential to lead to distress and the appearance of maladaptive behaviors. Hence, understanding and meeting the social and physical needs of animals are essential to the prevention or minimization of distress. Identifies situations and practices that can contribute to distress and adversely affect an animal's well-being.
Two points require emphasis: a state of well-being is more than just good health and the absence of pain, and needs are species-specific.It is helpful to keep in mind that no environment is free of stressors. Furthermore, even if a stress-free environment could be achieved, it would not necessarily be desirable. Stress is not always abnormal or harmful to well-being.
Stressors are common in the lives of animals in their natural environments, and a captive animal that had never experienced stress would be quite different in its behavior and physiology from the typical members of its species.Whether stress will lead to distress, with the appearance of maladaptive behaviors and physiologic and pathologic changes, and create a serious risk to an animal's well-being depends on the intensity and duration of the stress and the animal's adaptability. Rather than strive to keep a captive environment free of stressors, it is more realistic, and will serve animals' interests better, to try to identify and eliminate extreme forms of chronic or acute stress.
That can be achieved partly by designing the physical environment, caretaking regimens, and research procedures from the animals' perspective. It is also helpful to consider the kinds of experiences that animals can be given to help them cope with stressors in situations they are likely to encounter in a captive setting. Animal-centered approaches to stress and distress are essential, but they can easily be carried to an extreme. There are no animal utopias in nature or in artificial environments. No environments are entirely animal-centered.
Even if they were, the biologic makeup of animals includes paradoxes and contradictions that environmental conditions cannot fully resolve. The assumption that animals 'know what is best' for them is a charming fiction. The various activities they engage in, the goals they seek to reach, and the functions they carry out do not necessarily constitute a coherent, harmonious, and entirely beneficial whole; more often, they reflect compromises within the individual between conflicting or incompatible needs and tendencies. Some of the compromises can actually be potent sources of stress and can lead to distress.
That is likely to be the case, for example, for both mother and offspring in many nonhuman primate species during the period surrounding weaning. The weaning process can, in fact, be so stressful that it increases the infant's vulnerability. Other examples can be found in.Even if measures of stress and distress were wholly objective, concordant, and unequivocal, that would not always provide sufficient information on which to base practical decisions. One price of human stewardship, even if animal well-being were the only concern, is that human knowledge and human values necessarily influence the decision-making process. When data are lacking, purely anthropomorphic considerations are often helpful, if they are based on a solid understanding of the behavior of the species and the context.
In some contexts, humans might make decisions that animals themselves would make, as is often the case between human parents and children. To ensure that decisions are as humane as possible, more information on the sources and manifestations of stress and distress in captive environments is helpful. Agreed-on guidelines for the identification and reduction of stress and the prevention and minimization of distress can also serve a useful purpose. In the pursuit of humane concerns, however, it is essential to recognize the need for professional judgment and to preserve as much flexibility as possible in the process by which practical decisions are reached and implemented.The solutions to most of the problems concerning environmental sources of stress and distress in captive animals will eventually be provided by research. In the meantime, it is necessary to be sensitive to signs of stress and to take whatever steps are possible to control them—not only on humane grounds, but also because of the impact of stress on reproduction and research results.
Animals that are chronically stressed are altered behaviorally and physiologically to the extent that they can experience reproductive failure.Knowing the species being used and being familiar with the normal appearance and behavior of individual animals are the best preparation for detecting signs of stress and distress. The next step is to determine their source. Except for pain and illness, stress, and distress in captive environments usually result from some degree of encroachment of the six ecologic dimensions (described in ) on species-typical needs and behavioral tendencies. Those dimensions should be considered in designing captive environments and in planning management proce. Dures, and they should be evaluated when conditions appear to be causing unacceptable stress.Husbandry practices that contribute to distress should be corrected. The environment should be well defined and controlled (e.g., established temperature, humidity, ventilation, and illumination standards should be met, noise reduced, etc.). The housing, feeding, and care of laboratory animals should be appropriate for the species to promote their health and well-being.
Personnel that care for and use animals should be adequately trained. Generally, these issues are not a major source of disagreement. The attainment of well-being, however, might require consideration of other factors, such as environmental enrichment and socialization.Given the present state of knowledge, specific recommendations and guidelines are necessarily tentative. It is possible, however, to indicate the kinds of questions that are reasonable to consider when evaluating environmental sources of stress and distress that can be addressed through changes in husbandry practices. With the discussion of the six ecologic dimensions in as a guide, we offer the following questions as examples for use in assessing the adequacy of husbandry practices. Relationships with Conspecifics.Should the animal be housed alone or with others?.Does the animal belong to a species that is mainly solitary (such as cats) or that normally lives in social groups (such as dogs, nonhuman primates, and most rodents)?.Is the animal is housed with others, is continuous group living characteristic of the species (such as sheep), or are seasonal or other cyclic variations in sociability the rule (such as hamsters)?.If animals are housed in groups, are the number of animals and available space such as to prevent crowding?.Are the members of the group compatible?
Are some animals being picked on or always causing trouble?.Are the numbers or proportions of adult males, adult females, and immature animals in the group appropriate?.Have all members of the group been adequately socialized with conspecifics during their early development?.Are the animals familiar with each other?.Is fighting or aggressive dominance a normal feature of social relationships in the species? If so, are physical arrangements—such as the volume of space, the location of barriers, and the placement of food sources—appropriate to minimize aggression?.If offspring are to be separated from parents, when should this occur, which sex normally leaves the family group, and at what age? What provisions have been made to keep stress from becoming extreme? Shelter.Is the animal in a species that normally uses shelters, dens, or cover?.What functions do shelters, dens, and cover normally serve for the species (e.g., protection from elements or from predators or a depository for young)?.If shelters, dens, and cover are provided in the captive environment, what purposes are they expected to serve?
Are they adequately designed to fulfill these purposes?.Is sanitation a problem?.Does it appear that the animal's behavior is altered by the presence of shelters, dens, or cover so as to make it more fearful or more difficult to handle or to cause other effects that are undesirable from the standpoint of management and well-being?.Does the animal scent-mark? If so, is this considered in the provisions for sanitation of the cage? Spatial Architecture (Volume, Structure, and Topography).Does the volume of space meet the standards for the species recommended by the Guide for the Care and Use of Laboratory Animals (NRC, 1985) and the Animal Welfare Regulations (CFR Title 9)?.How much of the available space is actually used by the animal, and how is it used?.Does the animal display repetitive and stereotyped motor patterns or other behaviors that point to some inadequacy?.Can caging arrangements be improved by adding perches, climbing devices, or other structures? Feeding and Foraging Patterns.Is the animal's food consistent in amount and quality with recommended standards for the species?.What is the normal feeding pattern of the species?.Do animals normally meet their nutritional requirements in a single meal with long intervals between feedings, eat intermittently throughout the day, or show some other predictable pattern?.Are animals characteristically picky or wasteful feeders? Do they accept standard foods readily and consume them completely?
SOCIALIZATION AND HANDLINGSocialization is achieved through conspecific housing or through interaction with other species, including humans. The benefit to any individual animal, however, should be carefully evaluated before pair-housing is implemented or an animal is introduced to a group, and a suitable period and method of adaptation should be provided. Many laboratory animals benefit from interaction with people, but this should be undertaken with due consideration for the animal's experience and zoonotic potential. There is general agreement about the value of conspecific socialization for the well-being of most laboratory animals, although it is not always easily achieved, because of the requirements of the protocol, space, finances, and other constraints.It is well known that dogs respond favorably to direct interaction with humans and that their well-being can be enhanced by social, conspecific housing of compatible dogs. Socialization of puppies to humans and continued interaction with them might be the most stress-relieving practice for dogs. Human socialization should be included in every dog breeding program and stipulated in contracts for the purchase of dogs for research. Nonhuman primates might receive the greatest benefit from socialization with conspecifics, but direct human interaction can be beneficial under some circumstances, especially for an animal that is immature and singly housed.
A predictable cause of maladaptive behaviors in nonhuman primates is social isolation when they are young. If early maternal separation is necessary, young primates will benefit from frequent exposure to cagemates. Continuous housing of very young animals together is not advisable, however, because it produces excessive mutual clinging and emotional dependence that impairs well-being and impedes normal social development.
Where possible, infant nonhuman. Primates should be raised, at least through weaning, with their biologic mothers in a stable, species-typical social group in a predictable environment. Conspecific housing of incompatible animals and frequent changes in group composition lead to socially induced stress. Technicians responsible for the day-to-day care of nonhuman primates should not only understand the social behaviors of the species for which they are responsible, but also understand their role in maintaining social stability and controlling stress within and between cages or pens.There is a substantial literature on the effect of human handling on the physiology, behavior, and development of various animals (Newton and Levine, 1968). The effects of handling are influenced by an animal's age and genotype and by the duration and frequency of handling.
Most information has been obtained on laboratory rats. Handling pups between birth and weaning has been reported to have effects on many characteristics, including rate of growth and weight gain, learning, exploratory behavior, emotionality, physiology, responses to food and water deprivation, and the occurrence of some diseases or pathogens (Ader, 1967; Denenberg, 1969; Daly, 1973). Handling rats after weaning tends to be less effective. Comparable data on other species are lacking, but there are good reasons to assume that early handling, aimed at gentling animals and accustoming them to contact with humans, is likely to improve the docility and adaptability (and thus decrease stress) of most laboratory animals. ENVIRONMENTAL ENRICHMENTAs defined in, the well-being of an animal encompasses more than freedom from pain and distress and is evaluated not just on the basis of growth and reproductive records, but from a global perspective of behavioral and physiologic stability. Because many stressors are of environmental origin, it is often assumed that the well-being of laboratory animals can be improved by environmental enrichment that permits animals an opportunity to express species-typical behaviors.
Laboratory animals given the opportunity to perform species-typical behaviors may interact voluntarily with the enriched environment and participate in activities whose cessation could be interpreted as a change in well-being.Enrichment devices and environmental changes to promote well-being of nonhuman primates are being studied extensively. However, what is appropriate for nonhuman primates (and other species) is a matter of some debate, and research is needed to determine which methods actually improve animal well-being (Beaver, 1989). For example, it is assumed that the creation of a more naturalistic environment for nonhuman primates will permit the expression of the normal range of behaviors. But there is some uncertainty about the validity of the assumption, because it has been reported that the 'naturalness' of the environment is not as important to an animal's well-being as are events that are arranged to be contingent on the animal's behavior. Feeding puzzles, manipulanda, and artificial appliances. With which the animals can interact encourage investigation and activity and are generally acknowledged to enrich the environment (see Beaver, 1989).Although attention is being focused on nonhuman primates, methods for environmental enrichment of other species should be evaluated.
Concentration on enrichment of the environment by incorporating objects or devices within the cage should cause the extreme importance of social interaction, possibly the most important form of enrichment for most laboratory animals, to be ignored. The proper balance between conspecific and human social interaction, a cage and room environment developed with an understanding of the normal behaviors of the species, and caring personnel trained to handle and care for the species should be the goal. EXPERIMENTAL DESIGNThe objectives of some experiments require the production of stress or even distress (e.g., through food and water deprivation, maternal deprivation, social isolation, etc.), and investigators should be sensitive to the ethical concerns raised by such objectives.
Experiments should be justified, use the minimal number of animals consistent with an effective design and statistical analyses, and minimize the duration and magnitude of stress. Restriction of food intake to develop appropriate reward-motivated behaviors in behavioral studies, usually in rats, is common. In those experiments, rats are usually maintained at about 80% of their ad libitum feeding weight, which is considered neither unethical nor excessive deprivation.
Although novel foods might be used as environmental enrichment , the response to novel foods, in either an experimental or a husbandry context, can be stressful. Foods usually should not be changed in the course of an experiment.Caging conditions (e.g., single housing of rodents) and restraint (e.g., of rodents and nonhuman primates) produce stress, which can be so extreme or prolonged that an animal is unable to adapt and becomes distressed and maladaptive.
Those procedures often can be minimized by handling and appropriate adaptation procedures, respectively. Because the novelty of an experience increases an animal's emotional response to it, habituating laboratory animals to experimental procedures by regular handling and adaptation to potentially stress-producing procedures should be incorporated into experimental protocols. For example, stress is associated with the first experience of dogs introduced to the leash, monkeys restrained in a chair, or cage-reared rats removed from their cage.
Whether the stress of those experiences manifests itself in maladaptive behaviors (e.g., twirling on the leash, self-mutilation in the chair, or freezing and immobility, respectively) and thus distress will likely depend on factors external to the procedures themselves, such as previous experiences of the animal that led to expectations of pleasure or stress, familiarity with people, development of coping strategies for other events, and even time of day. Likewise, the biologically adaptive.
Response to stressful stimuli has been shown to be subject to the early experience of the animal (Melzack and Scott, 1957; Green, 1978). Adaptation and handling to minimize stress and prevent distress can be applied to many experimental settings and procedures: chair restraining of nonhuman primates (when necessary for short periods) should be preceded by a series of brief introductions to the chair by a familiar person and rewarded by favorite foods either in the chair or immediately on returning to the home cage. Movement of animals to test chambers or laboratories should be preceded by several days or weeks of conditioning trips in which no aversive interaction takes place and food reward is provided. Through such means, a 'transfer cage' or leash can signal a pleasurable event for the animal and facilitate a difficult task for the responsible person. In each case, the goal should be the positive association of the desired task favorably with a conditioned stimulus, such as the transfer cage, leash, or familiar technician. The stimulus need not always be a physical entity; the time of day or the ring of a bell can come to convey the same information, if presented in a predictable and routine manner and associated with the event to which the animal is being adapted.
Adaptation to strange or unusual objects or environments, before the experimental introduction of the animal to the object or environment, reduces the novelty and stress of the experience and the likelihood that it will affect the experimental results.Other experimental procedures and poor or inappropriate techniques, such as those common in blood withdrawal or antibody production, also can lead to stress. Amyx (1987) summarized procedures for antibody production, emphasizing that a reduction in volumes injected and a change in the site of injection minimizes the pain and distress of immunization procedures. Distress can be further minimized by sedative pretreatment, rather than use of restrainers. Blood withdrawal can lead to stress if the amount removed exceeds 1% of the animal's body weight.Adaptation and socialization are strategies for reducing the distress of laboratory animals, preventing or alleviating distress, and thereby enhancing their well-being.
Find guidance on performing survival surgery on animals as part of a protocol approved by the Institutional Animal Care and Use Committee (IACUC).Guidelines pertain to all species. However, special considerations may be necessary based on experimental- or species-related needs. Please consult with a Research Animal Resources (RAR) veterinarian to discuss any specific considerations prior submitting a protocol or protocol amendment for IACUC review.In addition, the more detailed serves as a reference for developing a surgical plan in rodents. Survival surgery: Animal recovers from the procedure and anesthesia. This surgery requires aseptic procedures, including surgical gloves, masks, sterile instruments, and aseptic technique.Terminal, acute, or non-survival surgery: Animal is humanely euthanized while still under anesthesia. Certain principles of asepsis may not apply depending on the procedure length. (below).Major surgical procedure: Surgery that penetrates and exposes a body cavity or any procedure that permanently impairs physical or physiological functions (e.g., laparotomy, thoracotomy, craniotomy, amputations).Minor surgical procedure: Surgery that does not penetrate or expose a body cavity or permanently impair physical or physiological functions (e.g., subcutaneous osmotic pump placement, skin biopsy).Sterilize: To eliminate agents injurious to health on equipment and supplies used in aseptic surgery.
Common methods include steam autoclaving, ethylene oxide gas, and cold sterilization.Disinfect/sanitize: To make physically clean and to remove and destroy agents injurious to health, to the maximum degree that is practical.Aseptic technique: Procedures before and during surgery to limit microbial contamination of the surgical site. Facilities requirements.
Dedicated workspaceDefined as an area within the lab that is free from unnecessary equipment and materials, easily sanitizable, and has limited traffic flow during procedures. Pre-operative considerations are an important part of planning surgical procedures.
Using appropriate intraoperative technique is essential for a good surgical outcome. This involves maintaining aseptic technique and conscientious tissue-handling during surgery.Basics for a successful surgery: 1. Assessing and ensuring appropriate anesthetic depthPrior to initiating surgery, confirm the appropriate anesthetic depth by checking the reaction to stimuli (e.g., toe pinch, palpebral reflex), body tone (e.g., jaw tone in swine), and physiologic parameters (e.g., heart rate, respiratory rate, etc.). Use multiple parameters to assess depth. Aseptic technique procedure. Keep hands within the sterile field created by the drape or instrument tray.
If you touch areas outside the sterile field or if a glove breaks, immediately change the contaminated article (e.g., gloves, gown). Carefully place instruments to maintain sterility. Immediately replace contaminated instruments. Keep surgical drapes clean, dry, and in place to provide appropriate protection. Keep the drape in place using towel clamps, sutures, or adhesives.
Reproductive Postoperative Care In Laboratory Animals Pdf File
Remove these carefully to prevent injury to the animal’s skin.3. Appropriate tissue-handling. Limited, gentle handling of tissues is essential to prevent infection, delayed healing, and incision site dehiscence. Examples of gentle handling include using atraumatic forceps during organ manipulation and periodically wetting exposed abdominal organs. IACUC requires surgical experience. Training can be provided by an experienced lab member or through RAR.4.
Closure proceduresAppropriate suture size, type, and closure pattern are necessary to prevent dehiscence and delayed healing. Please discuss any questions about size, type, or pattern prior to surgery with an RAR veterinarian.
RAR offers a suture training class by request that covers all of these properties. Suture choice considerations:Size: Appropriate size will vary by species and tissue.
For example, skin closure in a mouse will require a 5-0 or 4-0 gauge, whereas skin closure in a dog will require a 3-0 or 2-0 gauge.Type: Suture type is dictated by the surgical site and tissues involved. Properties of suture material include:. Absorption properties (absorbable vs.
Non-absorbable): Absorbable sutures are most commonly used within tissues, as they don’t have to be removed. Non-absorbable sutures are most commonly used in skin and are removed in 7-14 days. Composition (monofilament vs. Braided): Monofilament sutures are recommended for skin closure because they don’t wick bacteria.
Reproductive Postoperative Care In Laboratory Animals Pdf Free
Braided sutures tend to wick bacteria and should not be used in skin or in organs where contamination may be present (e.g., intestine, bladder).Pattern: The most commonly used suture pattern is the simple interrupted closure. It is good for tissue apposition, holds the incision closed even when a few sutures fail, and can be used for most situations. In high-tension areas (e.g., around limbs, on head), other patterns may be more suitable.Decrease potential dead space by suturing tissues layers while closing. If space is left between tissues, it can fill with fluid or blood, leading to impaired healing, infection, and/or abscesses.
Alternatively, if tacking down tissues with sutures is impossible, use a drain to limit fluid accumulation during the healing process.Skin closures are difficult in animals as they tend to chew or lick at the closure sites. Your veterinarian may recommend using intradermal sutures, surgical glue, or metal clips instead of or in addition to regular sutures. If skin closures dehisce, immediately contact the area veterinarian to determine appropriate treatment steps. Anesthetic recovery and post-operative procedures.
Post-operative monitoring and care must be performed per the, which can be found on the IACUC’s.In addition, address the following post-procedural care items in the surgical description: 1. Anesthetic recovery. Upon completing the surgical procedure, monitor animals during recovery from the anesthetic event. This is a critical time; careful monitoring may prevent unintended complications.
Provide appropriate recovery conditions including a warm environment free from objects that could cause harm. For example, use paper towels instead of corn cob bedding when recovering rodents, and remove large toys or water bowls from large animal pens. Record recovery notes and stay with the animal until it is fully ambulatory and able to reach food and water.2. AnalgesiaProvide post-procedure analgesia per the IACUC-approved protocol.
Consult with your area veterinarian if animals show signs of unrelieved pain after receiving analgesics. Surgical site monitoring and suture/staple removal. Observe and record the animal’s post-operative health and surgical site for a minimum of three days per the. This is only the required minimum; post-surgical monitoring may be needed for longer time periods in more severe surgical cases or if complication arise. Remove sutures or wound clips from the skin 7-14 days after surgery. Veterinary staff recommend that sutures in large species stay in for 10 days.
Record the date of suture or staple removal in the animal’s health record. This is often the last health record entry for animals that have otherwise healed from their procedure.Acute or non-survival surgery exceptions. Following are requirements for personnel conducting non-survival surgery at the University of Minnesota.Guidelines are intended for appropriately trained personnel (listed on an IACUC-approved animal protocol) who will be performing approved non-survival surgical procedures.In some non-survival protocols, aseptic technique may still be necessary to produce the best experimental outcome (e.g., extended anesthetic times, tissue collection for transplant) and consideration should be given to each situation.
Please contact an RAR veterinarian to discuss your specific situation before determining the best surgical procedures to follow.In addition to these guidelines, please refer to the when developing protocol plans. Instrument and equipment preparation. Visibly clean instruments are required at the beginning of surgery. Expired surgical materials (e.g., sutures, bandage material, surgical gloves, catheters) are allowed during the procedure.2. Medications. It is never acceptable to use outdated anesthetics, analgesics, euthanasia agents, or emergency drugs on any animal.
Examples of acceptable expired materials for use in non-survival surgery include IV fluid solutions and non-emergency drugs such as diuretics, contrast material, and antibiotics. Clearly and individually label and identify each expired material. It is best to locate all expired materials in the same area – physically away from other materials or drugs – and label materials as, “Expired – for acute use only”.
Use a designated storage area (e.g., cabinet or plastic bin) for expired materials and also label it as, “Expired – for acute use only”.3. Surgery location. Keep the preparation area separate from the surgical area.
Minimize traffic flow through the surgical area. Use non-porous, easily sanitized work surfaces. Keep the surgery area free of all equipment and materials not necessary for the procedure.4. Surgeon preparationIt is acceptable to wear procedure or surgical gloves. Animal preparation. At a minimum, clip the surgical site and remove loose hair and visible dirt/debris. For non-survival procedures of extended duration, attention to aseptic technique may be more important to ensure stability of the model and a successful outcome.