Improving transparency-A call to include social housing information in biomedical research articles involving nonhuman primates.

The social setting of animal subjects in the research environment has known effects on a variety of dependent measures used in biomedical research. Proper evaluation of the robustness of published research is dependent upon transparent, detailed, and accurate reporting of research methods, including the animals' social housing conditions. However, to date, most research articles utilizing nonhuman primates (NHPs) provide only partial data on this topic, hampering transparency, and reproducibility. Therefore, we call for the inclusion of information pertaining to the social aspects of the animals' housing conditions in publications involving NHPs to improve transparency. We argue that including this information in scientific publications is crucial for the interpretation of research findings in the appropriate context and for understanding unexplained variability in study findings. Finally, the inclusion of this information in publications will additionally familiarize scientists with how other researchers conducting similar studies are housing their animals and will encourage them to consider the implications of various housing conditions on their research outcomes.

Socialization in pigtailed macaques (Macaca nemestrina).

In response to new emphasis by regulatory agencies regarding socialization, behavioral management programs are allocating greater resources to maximize socialization opportunities for laboratory primates. Information regarding predictors of compatibility and risk of injury for all laboratory-housed species of macaques are needed to make social introductions and pairings as efficient and safe as possible. This study presents data on 674 pairs of pigtailed macaques (Macaca nemestrina) at the Washington National Primate Research Center over a 7-year period. During pair introduction, behavior was monitored while the degree of tactile contact was gradually increased. Based on observed behavior, pairs were assigned a behavioral introduction score (BIS), rating the quality of their interactions for each day of introduction. Animals deemed compatible, based on the BIS and technologist judgment, were allowed to progress to continuous contact with no staff present. A small proportion of animals deemed compatible at introduction was later separated for subsequent incompatibility or aggression; these proportions were higher in full contact compared to protected contact pairings. Of 674 pairs, 75% were deemed compatible at introduction in protected contact; 86 of these pairs were later transitioned to full contact with 98% compatibility. Predictors of decreased compatibility assessed during protected contact introductions included age (adult pairs were less compatible), the BIS on the last day of introduction, and aggression or injury during the introductory period. Predictors of injuries during the protected contact introduction process included: aggression on the first day of introduction, a negative BIS on the first or last day of introduction, and, surprisingly, the presence of grooming on the first day of introduction. Injuries during both introduction and subsequent pairing in protected contact were rare; however, injury rates increased significantly during full-contact pairing. These findings underscore the necessity of species-specific data to guide decision-making during the social introduction process. Am. J. Primatol. 79:e22556, 2017. © 2016 Wiley Periodicals, Inc.

Prior facility affects alopecia in adulthood for rhesus macaques.

Alopecia has proven to be a persistent problem for captive macaques; many cases continue to elude explanations and effective treatments. Although almost all captive populations exhibit alopecia rates higher than those seen in the wild, there also appear to be wide ranges in rates reported across primate facilities. In this study we looked at alopecia ratings for rhesus macaques (Macaca mulatta) obtained from five primary suppliers and currently housed at the Washington National Primate Research Center (WaNPRC). There were significant differences in alopecia ratings based on prior facility, despite the fact that animals had left their prior facilities at least 10 months previously and 60% had left more than 2 years previously. Possible explanations for the facility effect may include longer than anticipated time lines for alopecia amelioration, early experience effects, and genetic contributions. Our results should provide a cautionary note for those evaluating alopecia, treatments for alopecia, and the current environments of alopecic animals. It is possible that not all alopecia is caused, or can be ameliorated, by changes in the immediate environment. Am. J. Primatol. 79:e22551, 2017. © 2016 Wiley Periodicals, Inc.

A simple alopecia scoring system for use in colony management of laboratory-housed primates.

BACKGROUND: Alopecia in captive primates continues to receive attention from animal care personnel and regulatory agencies. However, a method that enables personnel to reliably score alopecia over time and under various conditions has proven difficult to achieve. METHODS: The scoring system developed by the behavioral and veterinary staffs at the Washington National Primate Research Center (WaNPRC) uses the rule of 9s to estimate the percentage of the body affected with alopecia (severity) and how the alopecia presents itself (pattern). Training and scoring can conveniently be managed using photographic images, cage-side observations, and/or physical examinations. RESULTS: Personnel with varying degrees of experience were quickly trained with reliability scores ranging from 0.82 to 0.96 for severity and 0.82 to 0.89 for pattern using Cohen's κ. CONCLUSIONS: This system allows for reliable and consistent scoring across species, sex, age, housing condition, seasons, clinical or behavioral treatments, and level of personnel experience.

Evaluating paint rollers as an intervention for alopecia in monkeys in the laboratory (Macaca nemestrina).

Adult female macaques (Macaca nemestrina) in the laboratory with alopecia from known or suspected overgrooming were subjects in a study evaluating effectiveness of a grooming device. The intervention evaluated was a paint roller on a metal bar hung on the cage, replaced weekly for 6 weeks. In a within-subjects design, 6 monkeys were randomly assigned to first experience the paint roller (PR) and later the control (C) condition (roller bar only); 6 monkeys were randomly assigned to C followed by PR. Coat condition scores quantifying alopecia were taken cageside weekly. During PR, PR use was scored 3 times a week based on wear. Alopecia scores during PR did not differ significantly from C. Although all the monkeys used the paint rollers, PR use scores did not correlate significantly with improvement in coat condition. Paint rollers do not appear to be an effective intervention for alopecia from overgrooming.

Floating limb behaviors and self-biting are associated in laboratory monkeys.

Early descriptions of floating limb behaviors in monkeys were associated with isolation rearing, a practice that ended more than two decades ago. The present authors named various forms of behaviors in which a leg is elevated for no apparent reason: "Floating Limb Suite" (FLS). Floating limb behaviors, identified in laboratory monkeys at the Washington National Primate Research Center (WaNPRC), consist of two subcategories distinguished by whether monkeys seem to react to the elevated leg or ignore it. Given the past association of isolation rearing with both self-biting (SB) and floating limb, the investigators predicted that SB and FLS would be associated in monkeys not reared in isolation. The investigators tracked, over a period of 3 years, the presence of FLS and SB in macaques (Macaca nemestrina, M. fascicularis, M. mulatta) and Papio cynocephalus at WaNPRC. SB and both subcategories of FLS occurred in mother-reared and surrogate-peer-nursery-reared monkeys. We analyzed presence of FLS, the two subcategories of FLS, and SB in 1,117 macaques monitored for up to 3 years, and 781 macaques observed for 8 min of structured data collection. The Papio sample size was insufficient for statistical analysis. Both sampling methodologies found FLS and FLS subcategories to be associated with SB. Nearly half the monkeys only engaging in seemingly harmless nonreactive forms of FLS also performed the potentially injurious behavior of self-biting. The positive association between FLS and SB suggests that monkeys exhibiting one of these behaviors are at a heightened risk for developing the other. One impediment to studying floating limb behaviors is lack of consensus on definitions. This study defined seven forms of apparently functionless elevated limb behaviors. Continued research on factors associated with floating limb behaviors across demographic groups and settings may provide insights into the etiology and treatment of self-biting.

Communicative contexts of the LEN facial expression of pigtailed macaques (Macaca nemestrina).

We have investigated the contexts of the LEN (lips forward-ears back-neck extended) or pucker, a species-specific facial expression of Macaca nemestrina, in four breeding groups. Using the behavior sampling method we recorded all LENs, associated behavior, and the identities of the individuals involved. Of 401 LENs initiated, 62% were directed to the observer, who never responded to them in any way. Infants and dams directed more LENs to the observer than did sires or other females. The average intraspecific LEN rate was 0.82 per monkey-hour, including LENs given in reciprocation. Excluding LENs given in reciprocation, sires LENned significantly more often to females and dams than to infants, and significantly more than females and dams LENned to them. Of LENs directed to conspecifics, 21% were reciprocated, 34% were followed by distance reduction, and 16% led to both. Reciprocating LEN responses occurred more often to LENs initiated by sires. Although primarily affiliative, some LENs occurred in agonistic contexts, suggesting a possible appeasing function or rejection of a LEN's social invitation. Aggression preceded 8% of conspecific LENs, and 15% of LENs were responded to by visual aggression. No response followed 47% of LENs. Affirming the conclusions of others, LENs are often directed by males to females before mating. LENs directed at cradled infants suggest that maternal LENs serve more than a summoning function. LENs directed to people by M. nemestrina usually seem to be inviting interaction or attention, but LENs by dams seem to reflect concerns over their infants. We speculate that at the most basic level the LEN emphasizes that the sender's gaze is fixed on the receiver. We propose that the LEN may have evolved in this quiet rainforest species to facilitate coordination of social activity when silence or stealth is advantageous.

Successful introduction of Macaca nemestrina infants to their mothers after cesarean delivery.

Four Macaca nemestrina infants delivered via cesarean section were introduced to their mothers after surgery. All 4 introductions were successful, although methods differed slightly between dam-infant pairs. Pairs were considered successful when the mother displayed affiliative behavior towards the infant (including grooming), cradled it ventrally, and nursed it sufficiently to maintain infant health. The dams were sedated lightly with ketamine prior to introduction to reduce the possibility of aggression to caregivers and infants. The dams were checked for lactation, and each infant was swabbed with its placenta and with its mother's vaginal secretions prior to placement in the dam's cage. During the initial exposure, all 4 mothers picked up their infants within 1.5 h after introduction. Three of the 4 dam-infant pairs were fully successful during the initial exposure (24 h postdelivery), that is, the infants began to nurse within 2.5 h of affiliative contact. The 4th dam-infant pair required 3 d of successive exposures before the infant was nursed adequately. Infant health and maternal behavior determined the length of exposure. The optimal duration of these introductory encounters appeared to be between 2 and 3.5 h, to allow sufficient time for the dam's recovery from sedation while avoiding adverse effects on infant health. These observations demonstrate that cesarean-delivered M. nemestrina infants can be successfully united with their mothers, although it sometimes may require prolonged exposures on successive days.

Subacute necrotizing encephalopathy in a pig-tailed macaque (Macaca nemestrina) that resembles mitochondrial encephalopathy in humans.

A male pig-tailed macaque (Macaca nemestrina), approximately 5 years old, was found to be vision-impaired and to have profound behavioral abnormalities, including hyperactivity and self-injurious behavior that was not amenable to amelioration by environmental enrichment. Facial and skeletal dysmorphisms also were noted. Magnetic resonance imaging (MRI) and positron emission tomography (PET) scanning revealed areas of possible infarction in the occipital lobes and megaventriculosis. At necropsy, following euthanasia for humane reasons, severe polio- and leukoencephalomalacia accompanied by megaventriculosis were seen in both occipital lobes and in several sulci of the parietal and frontal lobes. Light microscopic findings included loss of neocortical structure, with necrosis, neuronal loss, astrogliosis, vascular proliferation, mild spongiosis, and demyelination. The extent and severity of lesions were most pronounced in the occipital lobes and were greater in the left than in the right hemisphere. Other lesions included mild bilateral atrophy of the optic nerves, thymic involution, necrotizing dermatitis due to trauma, and a spectrum of spermatozoal abnormalities. The imaging and gross and light microscopic changes found in this animal resemble the mitochondrial encephalopathies of humans; this was corroborated by results of immunohistochemical analysis demonstrating decreased expression of enzymes of the mitochondrial oxidative complex ([OC]-I, -III, and -IV) in brain and muscle, and detection of fibrinogen immunoreactivity in neurons and glial cells. The spermatozoal defects may represent yet another aspect of a mitochondrial defect.

Factors predicting increased incidence of abnormal behavior in male pigtailed macaques.

To identify factors predicting abnormal behavior in laboratory monkeys, we observed all available singly housed 4- to 11-year-old male pigtailed macaques (Macaca nemestrina), the species/age/sex group most likely to be referred to the Washington National Primate Research Center's Psychological Well-Being Program for behavioral assessment. Of the 87 subjects, 29 had been referred to the program whereas 58 had not. Abnormal behavior was unrelated to the subject's housing location (biocontainment vs. other facility) or invasiveness of research. Nursery-reared subjects displayed more abnormal behavior than mother-reared subjects. Across and within rearing categories, the proportion of the first 48 months of life spent singly housed was positively related to the amount of abnormal behavior at maturity. This effect was stronger for subjects separated from the mother for clinical rather than experimental reasons, and least for mother-reared subjects. Locomotor stereotypy, by far the most frequent form of abnormal behavior, was positively related to time in single housing but was unrelated to rearing. These results reinforce the importance of tactile social contact during juvenility for the prevention of abnormal behavior in social primates. They also suggest that self-directed abnormal behaviors and locomotor stereotypies have different etiologies.