Recognition and Alleviation of Pain and Distress in Laboratory Animals (1992) / Chapter Skim
Currently Skimming:
4 Recognition and Assessment of Pain, Stress, and Distress
4 Recognition and Assessment of Pain, Stress, and Distress
Pages 32-52
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 32... ...
It is intended to enable readers to recognize and assess pain, stress, and distress in laboratory animals for the purposes of developing therapeutic, environmental, and behavioral strategies for decreasing them and lessening their impact on experimental data. The recognition of pain, pain-induced distress, and non-pain-induced distress in animals is ethically necessary for proper clinical management of animals to ensure their well-being and to reduce research variability.
|
From page 33... ...
It must be emphasized that stress can still affect experimental results even if an animal under stress seems to be adapting and is manifesting no maladaptive behavioral or physiologic signs. CLINICAL APPROACHES TO THE ASSESSMENT OF PAIN One of the more important responsibilities in the use of animals for biomedical research is to recognize clinical signs associated with pain.
|
From page 34... ...
Assessment of signs of less severe pain involves at least some subjective interpretation and requires careful clinical observation and familiarity with animals' responses to similar situations (Some, 19871. Animals in pain often display an appearance that is best described as an "absence of normal behavior." Normal behavior can be characterized by various species-typical actions, such as cats' response to stroking, goats' head pushing, and pigs' or primates' general activity and vocalization.
|
From page 35... ...
Those signs can often be associated with activation of the sympathetic nervous system as manifested in increased heart and respiratory rate, dilated pupils, increased body temperature, sweating, and muscle tremors. Elicitation of a response associated with pain, such as movement of the head toward the area being palpated, might be necessary to show that the animal is in pain and to locate the painful area.
|
From page 36... ...
Even if a cause is identified and corrected, maladaptive behaviors might persist and require careful diagnosis and treatment (Chapter 51. Classification of Procedures Likely to Cause Pain As with all surgical procedures, appropriate anesthesia should be used to render the animal insensitive to pain.
|
From page 37... ...
, anorexia, moderate guarding Thorax Reluctance to move, Sternal approach, Continual respiratory changes high; lateral (rapid, shallow) , approach, slight depression to moderate Spine, cervical Abnormal posture of head Moderate to Continual and neck, reluctance severe to move, abnormal gait "walking on eggs" Spine, thoracic Few signs, often moving Slight Short or lumbar immediately aBased on observations of dogs.
|
From page 38... ...
38 Cal Cq so U)
|
From page 41... ...
Nonhuman Primates Nonhuman primates show remarkably little reaction to surgical procedures or to injury, especially in the presence of humans, and might look well until they are gravely ill or in severe pain. Viewing an animal from a distance or by video could aid in detecting subtle clinical changes.
|
From page 42... ...
Pain in one limb usually results in limping or holding up of the affected limb with no attempt to use it. Cats in severe or chronic pain look ungroomed and behave markedly differently from normal.
|
From page 43... ...
Horses Horses in acute pain show reluctance to be handled, and their other responses are varied: periods of restlessness, interrupted feeding with food held in the mouth uneaten, anxious appearance with dilated pupils and glassy eyes, increased respiration and pulse rate with flared nostrils, profuse sweating, and a rigid stance. In prolonged pain, their behavior might change from restlessness to depression with head lowered.
|
From page 44... ...
Rigid posture can lead to a lack of grooming because of an unwillingness to turn the neck. In acute abdominal conditions, such as intestinal strangulation, cattle adopt a characteristic stance with one hind foot placed directly in front of the other.
|
From page 45... ...
RECOGNITION AND ASSESSMENT OF STRESS AND DISTRESS The most potent sources of stress in captive environments, other than pain, are likely to fall within the six ecologic dimensions described in Chapter 3; some of the most common are summarized in Table 4-4. Some useful information for a given species on conditions in the captive environment that are likely to be stressful can be gleaned from descriptions of the behavior of the species in its natural habitat, but such information is no substitute for data based on experiments carefully conducted .
|
From page 46... ...
That variability can be decreased in some common laboratory animals, such as mice and rats, in which generations of breeding have tended to produce animals that respond to stressful stimuli relatively uniformly (Hughes and Lang, 1983~. But variability is accentuated in highly outbred populations, such as dogs and cats, or in such a highly diverse order as nonhuman primates.
|
From page 47... ...
TABLE 4-5 Some Behavioral, Physiologic, and Biochemical Indicators of Well-Being Behavioral Physiologic Biochemical Grooming Temperature Corticosteroids Appetite Pulse Catecholamines Activity Respiration Thyroxin Aggression Weight loss Prolactin Facial expression Blood-cell count p-Endorphin Vocalization Blood-cell structure ACTH Appearance Cardiac output Glucagon Posture Blood flow Insulin Response to handling Vasopressin Substance P aDepartures from normal behaviors and characteristics are suggestive of changes in wellbeing. A knowledge of species-typical and individual-specific behaviors and clinical values is essential.
|
From page 48... ...
The recent focus on the "psychologic well-being" of nonhuman primates has raised the issue repeatedly, and many have proposed to improve psychologic well-being with enrichment devices or programs. Although nonhuman primates have received nearly all the attention, it should be asked whether other laboratory animals are in distress as a result of environmental monotony in standard housing or lack of other unidentified components of the environment.
|
From page 49... ...
Although an animal that shows such behavior is not necessarily in distress, the potential transition period between acute stress and distress should be of concern to investigators and animal staffs. The duration of atypical behaviors and the type of behaviors involved should constitute a warning that an animal needs attention; serious attempts must be made to alleviate the potential for distress.
|
From page 50... ...
Skilled observers who know the behavior of a particular species or strain of animal and of the individual animals under their care could provide a reliable assessment of the state of the animals. That reliability is seriously compromised when few animal care staff and researchers are afforded the time or training necessary for them to become skilled observers.
|
From page 51... ...
The site of origin of those substances influences the physiologic stress response, which has two categories of duration: a rapid increase in circulating neurally derived substances with a short duration of action and a slower increase in endocrine-derived substances with a longer duration of action. Acute stress surgery, postoperative pain, burns, anesthesia, cardiac arrest, exercise, and sometimes headache-results in the hypothalamic secretion of corticotropin-releasing factor (CRF)
|
From page 52... ...
An acute stressor can produce a transient but important change in some characteristics; a chronic stressor can lead to the establishment of a new steady state of plasma hormones and heart function that might not be very different from the original. Different animals can respond to a given event differently, sometimes because of a lack of opportunity to habituate or acclimate.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.