Hair pulling: a review.

Hair pulling has been reported in humans, six different non-human primate species, mice, guineapigs, rabbits, sheep and muskox, dogs and cats. This behaviour seems to occur only in subjects who are confined in an artificial environment. It has been classified as a mental disorder in humans, as a behavioural pathology in animals. The hair is not only pulled but also, in most species, ingested. Hair pulling can be both self-directed and partner-directed, contains elements of aggression, manifests more often in females than in males, is associated with psychogenic distress, and resists treatment. Research data collected from affected animals are probably not normative, hence scientifically unreliable. The preemptive correction of husbandry deficiencies causing long-term stress may prevent the development of this bizarre behaviour in healthy subjects.

Common husbandry-related variables in biomedical research with animals.

Common, often overlooked, variables in biomedical research with animals are reviewed. The barren primary enclosure is an abnormal living environment for laboratory animals. Species-appropriate enrichment attenuates some of the distress resulting from chronic understimulation. Social deprivation distress of individually-caged social animals is best mitigated by the provision of compatible companionship. Biotelemetry and positive reinforcement training avoid or minimize stress reactions that typically occur when animals are forcibly restrained during procedures. The variables, 'light' and 'position of living quarters' are inherent in the multi-tier caging system. To date there is no satisfactory alternative other than the single-tier cage arrangement that eliminates both variables. Removing test animals from their familiar home environment and from their cage mates for procedures introduces stress as an avoidable influential variable. Music may become an important variable if not all subjects are exposed to it. Disturbance time cannot be controlled as an extraneous variable but it should at least be mentioned to explain possible incongruities of data. A positive relationship between animal care personnel and research subjects is a key requisite to minimize stress as a data-confounding variable.

Working with rather than against macaques during blood collection.

Training macaques to cooperate during blood collection is a practicable and safe alternative to the traditional procedure implying forced restraint. It takes a cumulative total of about 1 hr to train an adult female or adult male rhesus macaque successfully to present a leg voluntarily and accept venipuncture in the homecage. Cooperative animals do not show the significant cortisol response and defensive reactions that typically occur in animals who are forcibly restrained during this common procedure.

Compassion for animals in the laboratory: impairment or refinement of research methodology?

There are now signs in the United States as well as in Europe that the importance of a positive human-nonhuman animal relationship in research laboratories is appreciated more seriously. In addition to knowledge and skills, primary attributes of animal research personnel must be feelings of compassion and sensitivity toward animals to safeguard the reliability of scientific research data.

Artificial weaning of Old World monkeys: benefits and costs.

Permanent mother-infant separation prior to natural weaning is a common hus-bandry practice in monkey breeding colonies. In the United States, all eight Re-gional Primate Research Centers have such colonies. Under undisturbed conditions, Old World monkey mothers wean their infants at the age of about 1 year (Hall & DeVore, 1965; Poirier, 1970; Roonwal & Mohnot, 1977; Southwick, Beg, & Siddiqi, 1965). Natural weaning is a gradual process. It implies that the mother, over a period of several weeks or months, more and more consistently discourages her infant to suck on her breasts. Once the mother stops nursing the infant for good, the affectionate bond between the two is not broken (Altmann, Altmann, Hausfater, & McCuskey, 1977; Lindburg, 1971; Poirier, 1970; Roonwal & Mohnot, 1977). The young usually remains in the ma-ternal group at least until prepuberty. Under confinement conditions, artificial weaning is an abrupt occurrence that takes place several months prior to the biologically normal age of weaning. It im-plies that the still-nursed infant is taken away from the mother and subsequently reared alone or with other artificially weaned infants.

The attending veterinarian's contract of employment: curse or blessing for animals in research institutions?

When attending veterinarians are not provided adequate job security by research in-stitutions, there is no guarantee that they are reliable allies of nonhuman animals and implement the provisions set forth in the federal animal welfare regulations.

The myth of the aggressive monkey.

Captive rhesus macaques are not naturally aggressive, but poor husbandry and handling practices can trigger their aggression toward conspecifics and toward the human handler. The myth of the aggressive monkey probably is based on often not taking into account basic ethological principles when managing rhesus macaques in the research laboratory setting.

Time budget of caged rhesus monkeys exposed to a companion, a PVC perch, and a piece of wood for an extended time.

The present investigation assesses the percentage of time that rhesus monkeys (Macaca mulatta) are kept occupied by a more complex cage environment. Sixty animals were continuously exposed for at least 1.5 years to a compatible companion for social interaction, a suspended plastic pipe for perching, and a branch segment for gnawing. The behavior of the partners of each pair was recorded for 60 minutes when the animals were not distracted by human activities. Individuals spent an average of 23.5% of the time interacting with the companion, but only 10.4% with the plastic pipe and 4.8% with the branch segment. Differences were statistically significant. Females were socially more active than males. Subadult animals (3.5-4 years) used both inanimate objects significantly more than did adult animals (9-30 years). It was concluded that (1) a compatible companion, a suspended plastic pipe, and a loose branch segment remain effective stimuli for caged rhesus monkeys after more than 1 year of exposure and (2) a compatible companion is of greater stimulatory value-particularly for adults-than are inanimate objects.

Behavioral responses of unrelated adult male rhesus monkeys familiarized and paired for the purpose of environmental enrichment.

An attempt was made to pair ten unrelated, adult male rhesus monkeys that had been kept in single cages for several years. Potential companions were first given the opportunity to establish clear-cut rank relationships (unidirectional fear-grinning and/or withdrawing) during a 5-day period of noncontact familiarization. Only then were they paired in a different double cage. Rank relationships were confirmed within the first 6 minutes after pairing without the occurrence of any biting and fighting. A total of four physical aggressions (slapping) were observed in all five dyads during 5 hours of observations on the first 5 days after pairing. It was concluded that the establishment of clear-cut rank relationships prior to pairing was instrumental in this extremely low incidence of aggression.

Behavioral responses of unrelated rhesus monkey females paired for the purpose of environmental enrichment.

An attempt was made to socialize unrelated and unfamiliar adult rhesus monkey females that had lived in single cages for more than one year. Partners first were given the opportunity for noncontact familiarization in partitioned double cages. They were then transferred into an ordinary double cage. Clear-cut rank relationships were evident within the first 90 minutes of pair formation in 94% (17/18) of dyads tested. Only 28% (5/18) of pairs resorted to fighting (in no case with infliction of serious injury), while 50% (9/18) engaged in social grooming or hugging during this initial phase of pair formation. Eighty-three percent (15/18) of pairs were compatible, with none of the partners showing signs of depression and none inflicting serious injury on the other. Seventeen percent (3/18) of pairs were incompatible (two cases of depression, one serious tail injury) and were separated. It was concluded that the barren environment of singly caged rhesus monkey females can be enriched with little risk by carefully making them compatible companions.