Restoration of Reproductive Hormone Concentrations in a Male Neutered Dog Improves Health: A Case Study.

This case study reports on the use of hormone therapy to treat a dog with a range of physical and behavioral signs that began after gonadectomy. A male mixed breed dog neutered at 7 months of age presented at 1 year with health issues impacting quality of life. Reduced mobility, limping, rapid weight gain, and fear of unfamiliar people were treated over the next 3 years with trials of pain medication, joint supplements, thyroxine, antidepressant, and significant diet restrictions. Frequent carprofen administration and daily joint supplements reduced limping, but mobility was still poor. Weight stabilized on a strict diet but fear and anxiety responses to strangers continued to worsen. Hormone restoration therapy was initiated when the dog was almost 4 years of age. Weekly subcutaneous administration of testosterone cypionate (0.5 mg/kg) significantly reduced pain and increased muscle mass, thereby improving mobility. However, supraphysiologic concentrations of luteinizing hormone were not reduced with testosterone therapy so a gonadotropin-releasing hormone agonist was implanted. After hormone restoration, appetite was reduced, and anxiety and fear behaviors became manageable. The testosterone and gonadotropin-releasing hormone agonist treatment was easily administered, had no known side effects, and the owners were pleased with the outcome.

Effects of intratesticular vs intraepididymal calcium chloride sterilant on testicular morphology and fertility in dogs.

BACKGROUND: Both stray and free-roaming owned dogs contribute to the serious global dog overpopulation problem. Many dog owners are unwilling to have their pet castrated for various reasons, including a reluctance to have their dog's behavior changed. A non-surgical method of sterilizing both stray and owned dogs would help to prevent unwanted litters. Previous studies have shown that intratesticular injection of calcium chloride dihydrate (CaCl2) in alcohol is a promising and cost-effective alternative to surgery for stray dogs, with testosterone significantly decreased and sexual activity eliminated. The aim of this study was to compare the use of a solution of 20% CaCl2 in 95% ethanol injected into the testicles or into the head of the epididymis. METHODS: A total of 148 dogs divided into 4 groups (2 experimental and 2 control) were respectively injected with CaCl2 or saline solution into the testicle or epididymal head (ultrasound-guided). The animals were examined at 0, 3, 6, and 9 months for sperm quality, concentration of testosterone in serum, and side effects; at 0 and 5 months with contrast-enhanced ultrasound (CEUS) to enhance the morphological aspects/alteration of the testicular parenchyma or epididymis; and at 9 months when all were castrated for histological examination. RESULTS: All dogs treated with CaCl2 became sterile with azoospermia achieved over the 9-month study. The concentration of testosterone in serum significantly decreased following intratesticular treatment with CaCl2. No adverse effects were noted. CONCLUSIONS: A single, bilateral intratesticular injection of 20% CaCl2 in 95% ethanol was confirmed to be a reliable method for induction of sterilization in male dogs. The approach showed long-term efficacy and may reduce sexual behavior, with the additional benefits of low-cost and ease of use, making this nonsurgical method appropriate for use in stray dogs. Sterility was also achieved if injected in the head of the epididymis but no significant decrease in serum concentration of testosterone occurred. Moreover, performing the intraepididymal injection into the epididymal head was as time consuming as orchiectomy. This approach may be optimal for use in owned dogs where anatomical integrity and testosterone maintenance is preferred by the owner.

Genetic influences on response to novel objects and dimensions of personality in Papio baboons.

Behavioral variation within and between populations and species of the genus Papio has been studied extensively, but little is known about the genetic causes of individual- or population-level differences. This study investigates the influence of genetic variation on personality (sometimes referred to as temperament) in baboons and identifies a candidate gene partially responsible for the variation in that phenotype. To accomplish these goals, we examined individual variation in response to both novel objects and an apparent novel social partner (using a mirror test) among pedigreed baboons (n = 578) from the Southwest National Primate Research Center. We investigated the frequency and duration of individual behaviors in response to novel objects and used multivariate factor analysis to identify trait-like dimensions of personality. Exploratory factor analysis identified two distinct dimensions of personality within this population. Factor 1 accounts for 46.8 % of the variance within the behavioral matrix, and consists primarily of behaviors related to the "boldness" of the subject. Factor 2 accounts for 18.8 % of the variation, and contains several "anxiety" like behaviors. Several specific behaviors, and the two personality factors, were significantly heritable, with the factors showing higher heritability than most individual behaviors. Subsequent analyses show that the behavioral reactions observed in the test protocol are associated with animals' social behavior observed later in their home social groups. Finally we used linkage analysis to map quantitative trait loci for the measured phenotypes. Single nucleotide polymorphisms in a positional candidate gene (SNAP25) are associated with variation in one of the personality factors, and CSF levels of homovanillic acid and 3-methoxy-4-hydroxyphenylglycol. This study documents heritable variation in personality among baboons and suggests that sequence variation in SNAP25 may influence differences in behavior and neurochemistry in these nonhuman primates.

An evaluation of nest-building behavior by sanctuary chimpanzees with access to forested habitats.

All of the great apes build nests, but captive chimpanzees rarely have vegetation from which to build nests. The forested environment at Chimp Haven does allow captive chimpanzees to build nests of natural vegetation. Between February 2007 and December 2010, 238 nests were found in 2 forested habitats. Nests were made of naturally available vegetation, and more nests were made on the ground than in the trees (Z = 7.27, p < 0.001); nests were also built in the interior forest rather than on the periphery (Z = 7.06, p < 0.001). There was no correlation between the number of months in the habitat and the nests built per chimpanzee (rs = -0.07, p = 0.52). More nests were observed when more wild-born females were in the group (rs = 0.27, p = 0.01), and during warmer temperatures (rs = 0.45, p < 0.001). These findings support the goal of naturalistic environments in suitable climates for captive chimpanzees.

Neurobehavioral Integrity of Chimpanzee Newborns: Comparisons across groups and across species reveal gene-environment interaction effects.

The aims of this article are to describe the neurobehavioral integrity of chimpanzee newborns, to investigate how early experiences affect the neurobehavioral organization of chimpanzees, and to explore species differences by comparing chimpanzee newborns to a group of typically developing human newborns. Neurobehavioral integrity related to orientation, motor performance, arousal, and state regulation of 55 chimpanzee (raised in four different settings) and 42 human newborns was measured with the Neonatal Behavioral Assessment Scale (NBAS) a semi-structured 25-minute interactive assessment. Thirty-eight chimpanzees were tested every other day from birth, and analyses revealed significant developmental changes in 19 of 27 NBAS scores. The cross-group and cross-species comparisons were conducted at 2 and 30 days of age. Among the 4 chimpanzee groups, significant differences were found in 23 of 24 NBAS scores. Surprisingly, the cross-species comparisons revealed that the human group was distinct in only 1 of 25 NBAS scores (the human group had significantly less muscle tone than all the chimpanzee groups). The human group was indistinguishable from at least one of the chimpanzee groups in the remaining 24 of 25 NBAS scores. The results of this study support the conclusion that the interplay between genes and environment, rather than genes alone or environment alone, accounts for phenotypic expressions of newborn neurobehavioral integrity in hominids.

Life-long well being: applying animal welfare science to nonhuman primates in sanctuaries.

Nonhuman primates have become common in sanctuaries, and a few such facilities even specialize in their care. Sanctuaries can improve the well being of many unwanted primates, especially in terms of housing and socialization. However, diverse facilities call themselves sanctuaries, and they have varying conditions, care programs, and restrictions. In addition, a general lack of regulation of sanctuaries for nonhuman animals creates problems in enforcing even minimal standards. The application of animal welfare science in the sanctuary setting can help foster high standards and empirically based decision making. Sanctuaries offer excellent environments for studying primates without the limitations inherent in breeding, exhibition, and medical research facilities. However, some sanctuaries avoid scientific study. Many sanctuaries have little opportunity to study animal welfare in a systematic manner due to financial considerations or a lack of specific expertise among staff and volunteers. Most published sanctuary research involves reintroduction procedures at sanctuaries in source countries. Nevertheless, one chimpanzee sanctuary's successes in performing long-term studies and using simple evaluation methods, such as check sheets, have demonstrated the benefits of applying animal welfare science to sanctuary-housed nonhuman primates.

Maternal care and development of stress responses in baboons.

The ability to mount a successful response to threats is critical for an organism's survival. A key element of the stress response is its nonspecificity toward the stress source, with similar endocrine and behavioral changes expected under a variety of stressors. In this project we utilized an experimental design that accounts for multiple sources of variation to further understand the nature of stress responsivity and its relationship to the early rearing environment. A sample of baboons (n=73) was observed during the early phase of life in their social group, and then tested as juveniles in a challenging situation. Maternal cortisol levels were measured during the peripartum period. The challenging situation (individuals were isolated for a few minutes in a single cage) was designed to be a moderate source of psychological stress. Patterns in individual differences during the stress test were "mapped" by means of multidimensional scaling (MDS). After the observation was made, the subject was sedated and a blood sample was taken to measure cortisol levels. Our results indicate that when juvenile baboons are confronted with a source of psychological stress, they show a multidimensional behavioral response, probably mediated by the activation and synergic interaction among different neurohormonal systems that, ultimately, act on the hypothalamus-pituitary-adrenal (HPA) axis. Different components of the multidimensional, or nonspecific, behavioral response are associated with the quality and quantity of interactions with their mothers during early life. Juveniles whose mothers displayed higher levels of positive interaction were characterized by vigilant but less active reactions to the stress test, whereas juveniles of mothers that displayed high levels of stress-related behaviors had higher cortisol and locomotion levels.

Hormonal correlates of changes in interest in unrelated infants across the peripartum period in female baboons (Papio hamadryas anubis sp.).

In past research on human and nonhuman primates, maternal responsiveness and behavior has been thought of as an experiential, cognitive mechanism; however, recent findings have shown that maternal motivation and behavior may not be entirely divorced from the endocrine system. To investigate the relationship between interest in infants and the hormonal changes related to pregnancy, we examined the nature of social interactions across parturition between a large sample (n = 133) of adult female baboons (Papio hamadryas anubis sp.) and unrelated infants. Prepartum data were collected during ten 30-min focal observations for each subject. Each mother-infant pair was then observed through the infant's first 8 weeks of life. A total of 2325 h of observation was recorded. Urine was collected on 65 subjects, starting 5 weeks before the expected date of parturition and ending 4 weeks after parturition. Evidence for a connection between endocrine function and responsiveness toward infants was found. Affiliative behaviors during the prepartum period were positively correlated to the estrogen/cortisol ratio and high dominance rank. In the postpartum period, affiliative behaviors were positively correlated with prepartum progesterone and dominance rank, and negatively correlated with postpartum cortisol levels. Finally, a positive correlation was recorded during the postpartum period between prepartum progesterone and aggression, and a negative correlation between postpartum cortisol and aggression and submission. Our data suggest that the endocrine changes that may help regulate maternal care of offspring also influence the way in which pre- and postpartum female baboons interact with unrelated infants in their social group.

Excretion of urinary steroids in pre- and postpartum female baboons.

Steroid hormones are important regulators of a wide variety of reproductive and behavioral functions. We investigated the ability to track sex steroids and glucocorticoids in urine samples collected noninvasively from pre- and postpartum female baboons. Paired plasma and urine samples were collected every 2 weeks prior to and following birth in 10 females. Changes in concentrations of plasma steroids (estradiol, progesterone, and cortisol) were reflected in changes in urinary metabolite excretion (estrone conjugates, pregnanediol conjugates, and cortisol; r's>0.36, p's<0.001). A low correlation between prepartum plasma and urinary cortisol may reflect late-gestational changes in the production and/or metabolism of glucocorticoids. Steroid excretion profiles in a large sample of females giving birth and caring for healthy infants (n = 108) were compared with profiles obtained from females with poor maternal-fetal outcomes (late-term stillbirth, n = 14) and from females with significant postpartum problems with maternal care (n = 20). Mothers giving birth to stillborn infants had lower prepartum levels of urinary estrone conjugates and cortisol, suggesting reduced placental steroidogenesis. Mothers with postpartum behavioral difficulties had higher concentrations of prepartum estrone excretion, lower cortisol excretion, and elevated E/P ratios throughout the peripartum period. Noninvasive sample collection and enzyme immunoassay, therefore, have predictive utility regarding circulating steroid concentrations and can identify important endocrine correlates of physiological and behavioral abnormalities in baboons.

The role of the endocrine system in baboon maternal behavior.

BACKGROUND: Human mothers display a wide range of parenting skills, and although we have gathered a large body of evidence on a variety of factors affecting maternal behavior, we still know relatively little about the physiologic correlates of variation in parental behavior in primates. METHODS: Excreted gonadal and adrenal steroids were measured across parturition in a large sample (n = 89) of group-living female baboons. Maternal behavior data were collected during the first 2 months of infants' life. RESULTS: We found that changes in the excreted sex steroid hormones and cortisol were associated with baboon mothers' infant-directed behaviors. Mothers who displayed more stress-related behaviors, who were also prone to maintain less contact with their infants, had higher postpartum cortisol levels, higher prepartum pregnanediol-3-glucoronide (PdG) levels, and lower postpartum PdG levels. Mothers with higher prepartum cortisol levels showed higher levels of infant-directed affiliative behaviors. CONCLUSIONS: These results point toward the importance of the whole endocrine system as a functional unit in terms of enhancing maternal care in primates. The dramatic physiologic changes occurring across parturition may act, in coordination with the cognitive-experiential system, to help the mother cope with the additional challenges imposed by the newborn.

Solutions for research chimpanzees.

As one of humankind's closest animal relatives, the chimpanzee has proven to be a valuable but controversial research model. The author provides an overview of efforts to improve chimpanzee welfare, and describes a facility dedicated to providing lifelong care for these nonhuman primates following retirement from research.

Abnormal, abusive, and stress-related behaviors in baboon mothers.

BACKGROUND: Psychiatric disturbances during pregnancy and the postpartum period are especially serious, given the negative effects on the mother as well as the child. Understanding the causes of such disturbances has been difficult owing to the complexity of psychological, social, experiential, biological, and genetic factors involved. METHODS: To determine the potential utility of a nonhuman primate model for the study of postpartum disorders, the pathologic and stress-related behavior of 62 female baboons living in social groups was studied during pregnancy and after the birth of an infant. RESULTS: The prevalence of abnormal behavior and self-directed scratching (a measure of stress response) was higher after birth of the infant. Subjects displayed a significantly higher frequency per hour of these behaviors postpartum, which increased over 8 weeks. Abusive behaviors toward the infant were common, occurring in 55% of the subjects. Mothers with low dominance rank, who usually have lower levels of social support, had higher levels of abusive behavior during the postpartum period. CONCLUSIONS: Baboons show variation in measurable behaviors related to stress and abnormal functioning during the pre- and postpartum periods, indicating that a nonhuman primate model may be useful in the study of factors affecting postpartum psychiatric disorders and infant abuse.