Wolfle. Introduction: Environmental Enrichment, Pp. 79-82

ILAR Journal

Volume 46, Number 2, 2005

Wolfle. Introduction: Environmental Enrichment, pp. 79-82

The timely publication of this ILAR edition, with contributions from adozen authors offers insight and advice on environmental enrichment. Although environmental enrichment is now regarded as an integralcomponent of any experimental animal medicine program, until quiterecently, recognition of its importance and impact was of little or noconsequence. Ranging in topic from the USDA viewpoint, to speciesspecific enrichment strategies to facility design, this volume providesexpert advice on environmental enrichment that extends beyond theconfines of the animal facility, and takes into consideration itspotential positive and negative impacts on research results. Anotherinteresting perspective which is presented is whether or not theenrichment may actually be of less benefit than once assumed, or in theworst case scenario actually capable of harming the animals.

This volume comprises a balanced perspective on a fundamental building block of modern day laboratory animal medicine.

No questions or answers were provided with this summary.

Kulpa-Eddy et al. USDA Perspective on Environmental Enrichment for Animals, pp. 83-94

This article provides a brief historical background of the events & circumstances that led to the 1985 Animal Welfare Act (AWA) amendmentsand the development of the 1991 regulations promulgated by the USDA as aresult.

In the 1985 AWA amendments, two new mandatesbecame synonymous with environmental enrichment__exercise fordogs and environmental enhancement to promote the psychologicalwell-being of nonhuman primates.

Although Title 9 of the Code of Federal Regulations stated“Enclosures shall be constructed and maintained so as to providesufficient space to allow each animal to make normal postural and socialadjustments with adequate freedom of movement” the USDA prior to 1985 didnot believe exercise for dogs should be a mandatory requirement.

Throughout the 1990s the term “environmental enrichment” was definedin many ways but eventually came to refer to “any physical, social,design, or management feature that would improve the behavioralmicrohabitat for captive animals in any setting, including researchfacilities.”

Canine Exercise

USDA-APHIS in 1987 began promulgating regulations to enforce the AWAamendments of 1985. In 1989 a proposal was issued on standards for theexercise and socialization of dogs. It included standards on:

• Social contact while being housed, held or maintained
• Release for exercise and socialization
• Methods and periods of exercise
• Exemptions from exercise

In 1991 references to “socialization” were removed as APHISinterpreted the AWA as not including requirements for socialization, eventhough it was felt this was an integral part of the provision of adequateexercise. Instead dealers, exhibitors, and research facilities wereinstructed to consider providing positive physical contact with humansthat encourages exercise through play or similar activities

Nonhuman Primate Environment Enhancement

The intent of the1985 amendments and subsequent minimum standards was to allow for moreexercise, play, and compatible social interaction for laboratory primatesthrough requirements for:

• Sufficient space to engage in species-typical behavior
• Enclosure complexities
• Manipulable objects
• Varying methods of feeding

Marine Mammals

Title 9 of the CFR requires that marinemammals, known to be social in the wild, be housed in their primaryenclosure with at least one compatible animal of the same or biologicallyrelated species. Exemptions to such housing require a written planincluding:

• Justification for the length of time the animal will be isolated
• Information on the type and frequency of enrichment and interaction
• Periodic review by the attending veterinarian

For safety and health purposes restrictions are placed on the typeof any nonfood item provided for entertainment or stimulation of marinemammals.

Adequate Enclosures for Flying (bats) and AquaticSpecies

Bats must be provided with sufficient unobstructed flyingenclosure volume to enable movement by flying and sufficient roostingspace to allow all individuals to rest simultaneously.

Enclosures for species that spend a significant portion of their time inwater (capybaras, beavers, river otters, etc) must be designed with bothdry and aquatic portions.

Implementation

By August 1991 facilities were required tohave written plans for providing exercise of dogs and promoting thepsychological well being of nonhuman primates. In an internal survey 25%of USDA inspectors felt the criteria for dog exercise plans did not makeclear what facilities needed to do to be in compliance and 45% expressedthe same opinion of the criteria for primate enrichment.

In April 1999 APHIS-Animal Care developedwritten guidance for field inspectors in interpreting Exercise for Dogs(CFR Section 3.8) in its inspection manuals “Animal Care Resource Guides”( Here the regulatoryrequirements for dog exercise are clearly delineated into acceptable andunacceptable methods. APHIS-AC recognizes that facilities usually fulfillthe exercise requirement by providing a larger primary enclosure but theybelieve socialization with humans and/or other dogs is also important forthe well-being of the dog.

USDA-APHIS interpretation of the AWA languagewas that social grouping of nonhuman primates would be the defaulthousing scheme. “In most cases we expect group housing to be the mostefficient and appropriate method of ensuring that the animals’ socialneeds are met.” Instances will be evaluated on their own merit whereshared housing would interfere with IACUC-approved research or healthcare or times when other compatible primates are unavailable.

A good enrichment plan will ensure that thenonsocial aspect of the environment has all of the elements necessary toallow expression of species-typical behavior. As individuals may reactdifferently to the same enrichment, the exact choice of such enrichmentswould be made on the basis of individual response observations.

Primates in psychological distress are besttreated, as they would be with any other form of organic illness, asprescribed by the attending veterinarian. Appropriate ameliorationtherapy may be environmental change, psychoactive medications, and/orother adjuncts. In severe refractory cases euthanasia may be the mostappropriate therapy.

Questions

1. In 1990 APHIS concluded that the scientific evidence availableleads us to conclude that ______alone is not the key to whether adog is provided the opportunity for sufficient exercise.

2.In 1981 Alex Pacheco co-founder of ______volunteered at the Institute for Biological Research and documentednumerous violations of the Animal Welfare Act. This highly publicizedcase, known as the ______Case promptedcongressional hearings by the House of Representative Subcommittee onScience, Research, and Technology.

3.T/FIn 1993 in an internal questionnaire of APHIS-Animal Care inspectorveryfew of those polled felt they were unable to distinguish compliance ofstandards set forth bytheAWA of 1985 fromviolation.

4.Inspectors assure that primates are in an environment where theycan express the main species-typical behaviors within the bounds ofresearch study demands. These include all but:

a)Affiliative contact with one or moreother primates

b)Normal resting, comfort-seeking, andself-maintenance behaviors

c)Regular release from home cages forexercise

d)Normal movement

e)Expression of cognitive, exploratory andforaging skills

Answers

1. Space

2.People for the Ethical treatment of Animals (PETA), Silver SpringsMonkey

3. False- more than one third

4. c

Benefiel et al. Mandatory “Enriched” Housing of Laboratory Animals: The Need for Evidence-based Evaluation, pp. 95-105

Key points:

*Environmental enrichment for laboratory animals was originallydeveloped as a paradigm for learning how experience molds the brain; ithas evolved, however, to become widely viewed as a potential method forimproving animal well-being.

*The term "housing supplementation" better describes the widerange of alterations to laboratory animal housing that has been proposedor investigated.

*Research institutions that receive funds from PHS agencies areobliged to comply with the Guide, and must consider environmentalenrichment for more than non-human primates, particularly for socialanimals that must be housed singly. Although social animals are notlisted by species, common laboratory rodents (regardless of sex) areconsidered social animals and, when possible should be housed in groups.The structural environment in the cage should include items that promote"animal well-being" and allow performance of species-typical posturesand behaviors.

*The literature contains many interesting ideas on how to improvethe standard laboratory environment; what is lacking is research thatshows how the often precise laboratory conditions required for reliableresearch can be maintained across significant variations and housingconditions.

*Changes in the environments of animals have important effects onbrain structure, physiology, and behavior--including recovery fromillness and injury--and on which genes are expressed in various organs.

*Numerous studies show how the brain and other organs respond toenvironmental change, and the data warrant caution, in that minor cagesupplementation intended for improvement of animal well-being may alterimportant aspects of an animal's physiology and development in a mannernot easily predicted from available research, and increase bothvariability and confounding.

*There is a widespread assumption that cage supplementation isalways better for animals, despite the paucity of data to support thisassumption. There is also a growing tendency to allow animals'preferences to define and direct what constitutes enrichment. Variousforms of housing supplementation, although utilized or even preferred bythe animals, may not only NOT enhance laboratory animal well-being, theymay be detrimental to the research for which the laboratory animals areused.

*Production might benefit from cage supplementation, and cagesupplementation might be considered an essential part of animalhusbandry when a lack of environmental stimulation causes chronic stressor other pathological states, or maladaptive behaviors. Althoughcertain species appear to require a more stimulating environment, or atleast social contact, to prevent maladaptive behavior or to promoteessential (e.g., social, reproductive, and maternal) behaviors, researchhas yet to provide consistent arguments that all species needimprovements in standard laboratory housing, or to make in convincingcase for what constitutes appropriate improvement.

*A strong case can be made for object and housing supplementationin NHP's to prevent or ameliorate self-injurious behavior (SIB) orself-directed biting, extreme forms of self-directed stereotypycommonly seen in approximately 5-12% of non-human primates housed insmall single cages with few or no opportunities for exploration ormanipulation of objects. Alleviation of SIB in nonhuman primates isoften achieved by socialization through paired or group housing;supplementing the environment by making available manipulative objects(i.e., puzzle feeders) suppresses whole body stereotypy the (e.g.,pacing and rocking) but not SIB.

*Supplementation of standard laboratory cages is fast becomingrule rather than exception in rodent housing, and given the degree of"chaos" such widely varied supplementation may introduce to the researchprocess, some points are proposed to guide such changes:

1.Animal welfare and environmental enrichment comprise different,not synonymous, dimensions of animal housing, and enrichment does notguarantee improved animal welfare.

2.Animals' environmental preferences are not a guideline to theirwell-being and can be physically detrimental.

3.The term housing supplementation may better describe cageadditions beyond feed, water, and bedding. This term establishes noexpectation with regard to the effects on the animals, and thus can beused to describe an experimental condition when the effects on animals’well-being are not yet known or are not the subject of a primaryquestion.

4. In many cases, neither laboratory animal science experts norresearchers can be certain whether supplementing the standard rodentcage compromises animal well-being or research results. When eitheroutcome is in question, environmental enrichment should not be mandatedby the institution or oversight agencies.

5. Alterations in housing that clearly promote better health,reproduction, and fitness are valuable to animals and those who use andcare for them. However, attempting to improve emotional states thatcannot yet be reliably measured may not be valuable for either theanimals or the research in which they are used.

6. Variability can be very difficult to control both within andbetween laboratories. For this reason, it is important not tounderestimate the small environmental differences that can havesignificant effects on research results.

Questions:

1.Instead of "environmental enrichment," what term betterdescribes the wide range of alterations to laboratory animal housingthat has been proposed or investigated?

2.T/F: Small environmental differences may account for thestrikingly different behavioral outcomes observed in mice thatparticipated in seemingly identical procedures conducted in differentlaboratories.

3.According to the authors, is it appropriate to use preferencetesting paradigms to establish enrichment guidelines, particularly inrodents?

4.What are two specific areas in which housing supplementationmight be expected to be of benefit?

5.T/F: Housing supplementation is an effective means of dealingwith SIB in nonhuman primates.

6.T/F: Animal welfare and environmental enrichment comprisedifferent, not synonymous, dimensions of animal housing, and enrichmentdoes not guarantee improved animal welfare.

7.T/F: Animals' environmental preferences are not a guideline totheir well-being and can be physically detrimental.

8.T/F: The term housing supplementation establishes no expectationwith regard to the effects on the animals, and thus can be used todescribe an experimental condition when the effects on animals’well-being are not yet known or are not the subject of a primaryquestion.

9.T/F: When it is unknown whether or not supplementing thestandard rodent cage compromises animal well-being or research results,environmental enrichment should not be mandated by the institution oroversight agencies.

10.T/F: Attempting to improve emotional states that cannot yet bereliably measured may not be valuable for either the animals or theresearch in which they are used.

Answers:

1.Housing supplementation

2.True

3.No... various forms of housing supplementation, althoughutilized or even preferred by the animals, may not enhance laboratory animal well-being and may be detrimental to the research for which thelaboratory animals are used.

4.Production, and in situations where a lack of environmentalstimulation causes chronic stress or other pathological states, ormaladaptive behaviors.

5.False- supplementing the environment by making availablemanipulative objects (i.e., puzzle feeders) suppresses whole bodystereotypy the (e.g., pacing and rocking) but not SIB in NHP's.

6.True

7.True

8.True

9.True

10.True

Garner. Stereotypies and Other Abnormal Repetitive Behaviors: Potential Impact on Validity, Reliability, and Replicability of Scientific Outcomes, pp. 106-117

Summary

Behavior is important for homeostasis. Examples include food choice andnest building.

When an animal is housed under conditions that prevent species-typicalbehaviors (e.g. nest building), which would normally allow it to control itsenvironment, it is likely to be under stress.

Stress or the abnormal behavior itself may affect physiology andhomeostasis.

The following criteria may be used to identify abnormal behaviors:

1. May only occur in captivity (e.g. stereotypies)

2. May be seen in the wild or in captivity, but performed underinappropriate circumstances or excessively

3. May involve self-injury, affect social interactions, or have adverseeffects on growth or reproduction.

4. May be specific to a certain subset of animals

5. May induce signs of distress in the animal or its companions

Abnormal behavior may affect the validity, reliability or replicability ofexperiments.

Successful environmental enrichments often reduce or prevent malfunctionalor maladaptive behaviors.

Enrichment may result in more normal physiology.

Evidence suggests that most stereotypies involve abnormal brain function.

Evidence exists that the brain mechanisms that produce ARBs also affectmeasures in behavioral experiments.

Enrichment might improve the validity, reliability and replicability ofbehavioral experiments.

Additional studies are needed to determine whether ARBs and enrichmentaffect the results of behavioral experiments.

Definitions/Terminology

Maladaptive behaviors - reflect a normal animal in an abnormal environment.The animal responds appropriately to an abnormal situation. (e.g.infanticide in mice due to overcrowding).

Malfunctional behaviors - abnormal environment leads to abnormal physiology,brain development or neurochemistry. (e.g. isolation rearing)

Environmental enrichment - the provision of biologically relevant resourcesor structuring to the cage that facilitate natural behaviors, particularlythose that allow the animal to control its environment or homeostasis.

ARB (Abnormal Repetitive Behaviors) - behaviors that are inappropriate,repetitive and unvarying in either goal or motor pattern.

Stereotypies - unvarying inappropriate repetition of a set of movements thatlack any goal or function (e.g. bar-mouthing, jumping, somersaulting inmice).

Impulsive/Compulsive Behaviors - repetition of an inappropriate goal withvariable flexible goal-directed behavior (e.g. barbering in mice).

Questions

1. The unvarying inappropriate repetition of a set ofmovements that lack any goal or function is called:

a. Replication

b. Reinforcement

c. Stereotypical behavior

d. Extinction learning

e. Compulsive behavior

2. T/F? Abnormally repetitive behaviors may reflectabnormal brain function.

3. Captive environments may affect the followingexperimental parameters:

a. Reliability

b. Validity

c. Replicability

d. All of the above

Answers

1.c

2. True

3. d

Weed and Raber. Balancing Animal Research with Animal Well-being: Establishment of Goals and Harmonization of Approaches, pp. 118-128

Summary:

This article provides a resource for the creation of a program that balances scientific goals with the well-being of the animals used to accomplish these goals. The terms “well-being” and “animal welfare” are often used interchangeably to describe the biological, physical and mental aspects of animals maintained in various settings; however, there is a lack of consensus regarding the specific definition of these two terms, as well as how they should be measured. Traditionally, the presence or absence of species-specific behaviors has been used to assess an animal’s well-being. The NRC has proposed criteria to assess the well-being of NHP’s, though these measures are generally adaptable to other species, as well:

1) Able to cope effectively with daily changes in environment

2)Able to engage in species-typical behavior

3) Display of maladaptive behavior should be minimal

4) Should display a balanced temperament

Animal Welfare Regulations do specify certain types of enrichment for some animals; the Guide expands on the AWA requirements by including the statement that animals should be able to demonstrate species-typical behavior; additionally, it states that animals should be allowed opportunities for motor and cognitive activity or social interaction.

The three R’s are mentioned, specifying that refinement is directly related to the well-being of animals

The team approach to the establishment of strategies is emphasized. The specific team members and their associated roles are as follows:

• Institution: responsible for establishing the culture that defines the care and use of animals within the organization; also identifies the IO (Institutional Officer)
• IO: legally authorized to commit resources that will ensure compliance with all governing regulations and guidelines.
• IACUC: Appointed by the IO, the IACUC’s role is to view and approve study proposals, evaluate scientific outcomes that may adversely affect well-being, ensure compliance, and promote animal well-being and good science.
• Scientist: works closely with other members of the team to develop study protocols and ensure that all team members have a clear understanding of the scientific goals and methodology; strives to harmonize scientific requirements with animal well-being issues
• Veterinarian: Having legal accountability for animal care and the authority to make decisions on behalf of the animals, the veterinarian must strive to balance scientific goals with animal health and well-being.
• Facility management and care staff: Effective persons in this role are familiar with the normal, expected species-typical patterns and are trained to recognize abnormal presentations; have a daily responsibility for assessment of animal well-being.
• Animal behaviorist: As one of the newly identified members of the team, the behaviorist participates on many levels to facilitate assessment of animal well-being and the documentation of program effectiveness and humane treatment of animals.

The measurement of well-being can be difficult to assess, and many physiological measures have been proposed as indicators of well-being, including weight changes, TPR’s, and cortisol levels.