The oxytocin receptor gene (OXTR) polymorphism in cats (Felis catus) is associated with “Roughness” assessed by owners

Physiological Assessment of the Health and Welfare of Domestic Cats-An Exploration of Factors Affecting Urinary Cortisol and Oxytocin

Physiological samples are beneficial in assessing the health and welfare of cats. However, most studies have been conducted in specialized environments, such as shelters or laboratories, and have not focused on cats living in domestic settings. In addition, most studies have assessed physiological stress states in cats based on cortisol, and none have quantified positive indicators, such as oxytocin. Here, we collected urine samples from 49 domestic cats and quantified urinary cortisol, oxytocin, and creatinine using ELISA. To identify factors influencing hormone levels, owners responded to questionnaires regarding their housing environment, individual cat information, and the frequency of daily interactions with their cats. Using principal component analysis, principal component scores for daily interactions were extracted. These results showed that the frequency of tactile and auditory signal-based communication by owners was positively correlated with the mean concentration of oxytocin in the urine. Additionally, this communication was more frequent in younger cats or cats that had experienced a shorter length of cohabitation with the owner. However, no factors associated with urinary cortisol concentration were identified. Our study indicates that interactions and relationships with the owner influence the physiological status of cats and suggests that oxytocin is a valuable parameter for assessing their health and welfare.

Reliability and Validity of Seven Feline Behavior and Personality Traits

Domestic cats are popular pets, and they have personalities, with stable behavior differences between individuals. Lately, feline behavior and personality have been studied with different approaches, for example, with owner-completed questionnaires. The majority of these studies, however, lack a sufficient validation and reliability assessment of the questionnaires used. We designed an online feline behavior and personality questionnaire to collect cat behavior data from their owners. Then, we ran a factor analysis to study the structure of personality and behavior in a dataset of over 4300 cats. For validation, we studied the internal consistency, test-retest reliability, inter-rater reliability, convergent validity and discriminant validity of this questionnaire and extracted factors. In addition, we briefly examined breed differences in the seven discovered factors: fearfulness, activity/playfulness, aggression toward humans, sociability toward humans, sociability toward cats, excessive grooming and litterbox issues. Most of the rank ordering of breeds within each trait paralleled what has been found in previous studies. The validity and reliability of the questionnaire and factors were good, strengthening owner-completed questionnaires as a method to collect behavioral data from pet animals. Breed differences suggest a genetic background for personality. However, these differences should be studied further with multidimensional models, including environmental and biological variables.

Association between temperament related traits and single nucleotide polymorphisms in the serotonin and oxytocin systems in Merino sheep

Animal temperament is defined as the consistent behavioral and physiological differences that are seen between individuals in response to the same stressor. Neurotransmitter systems, like serotonin and oxytocin in the central nervous system, underlie variation in behavioral traits in humans and other animals. Variations like single nucleotide polymorphisms (SNPs) in the genes for tryptophan 5-hydroxylase (TPH2), the serotonin transporter (SLC6A4), the serotonin receptor (HTR2A), and the oxytocin receptor (OXTR) are associated with behavioral phenotype in humans. Thus, the objective of this study was to identify SNPs in those genes and to test if those variations are associated with the temperament in Merino sheep. Using ewes from the University of Western Australia temperament flock, which has been selected on emotional reactivity for more than 20 generations, eight SNPs (rs107856757, rs107856818, rs107856856 and rs107857156 in TPH2, rs20917091 in SLC6A4, rs17196799 and rs17193181 in HTR2A, and rs17664565 in OXTR) were found to be distributed differently between calm and nervous sheep. These eight SNPs were then genotyped in 260 sheep from a flock that has never been selected on emotional reactivity, followed by the estimation of the behavioral traits of those 260 sheep using an arena test and an isolation box test. We found that several SNPs in TPH2 (rs107856757, rs107856818, rs107856856 and rs107857156) were in strong linkage disequilibrium, and all were associated with behavioral phenotype in the nonselected sheep. Similarly, rs17196799 in HTR2A was also associated with the behavioral phenotype.

Temperament in Domestic Cats: A Review of Proximate Mechanisms, Methods of Assessment, Its Effects on Human-Cat Relationships, and One Welfare

Temperament can be defined as interindividual differences in behavior that are stable over time and in different contexts. The terms 'personality', 'coping styles', and 'behavioral syndromes' have also been used to describe these interindividual differences. In this review, the main aspects of cat temperament research are summarized and discussed, based on 43 original research papers published between 1986 and 2020. We aimed to present current advances in cat temperament research and identify potential gaps in knowledge, as well as opportunities for future research. Proximate mechanisms, such as genetic bases of temperament, ontogenesis and developmental factors, physiological mechanisms, and relationships with morphology, were reviewed. Methods traditionally used to assess the temperament of cats might be classified based on the duration of procedures (short- vs. long-term measures) and the nature of data recordings (coding vs. rating methods). The structure of cat temperament is frequently described using a set of behavioral dimensions, primarily based on interindividual variations in cats' responses toward humans and conspecifics (e.g., friendliness, sociability, boldness, and aggressiveness). Finally, cats' temperaments have implications for human-animal interactions and the one welfare concept. Temperament assessment can also contribute to practical aspects, for example, the adoption of shelter cats.

Normal feline behaviour: … and why problem behaviours develop

Practical relevance: Cats are descended from a solitary, territorial ancestor, and while domestication has reduced their inherited tendency to be antagonistic towards all animals larger than their typical prey, they still place more reliance on the security of their territory than on psychological attachments to people or other cats, the exact opposite to dogs. Many feline problem behaviours stem from perceived threats to this security, often due to conflicts with other cats. Others are more developmental in origin, often caused by inadequate exposure to crucial stimuli, especially people, during the socialisation period. Strongly aversive events experienced at any age can also contribute. A third category comprises normal behaviour that owners deem unacceptable, such as scratching of furniture. Evidence base: This review identifies three areas in which basic research is inadequate to support widely employed concepts and practices in feline behavioural medicine. First, classification of cats' problem behaviours relies heavily on approaches derived from studies of their behavioural ecology and, to some extent, extrapolation from canine studies. Few studies have focused on cats in the home, the environment in which most behavioural disorders are expressed. Secondly, cats' chemical senses (olfactory and vomeronasal) are far more sensitive than our own, making it difficult for owners or clinicians to fully comprehend the sensory information upon which they base their behaviour. Thirdly, although the concept of psychological distress is widely invoked as an intervening variable in behavioural disorders, there are still no reliable measures of distress for pet cats in the home. Global importance: Psychological distress of some kind is the primary cause of many of the behavioural problems presented to clinicians, but surveys indicate that many more cats display the same clinical signs without their owners ever seeking help. The welfare of this 'invisible' group could be improved by veterinarians taking a more proactive approach to educating their clients about the behavioural needs of pet cats.

Dog-Owner Attachment Is Associated With Oxytocin Receptor Gene Polymorphisms in Both Parties. A Comparative Study on Austrian and Hungarian Border Collies

Variations in human infants' attachment behavior are associated with single nucleotide polymorphisms (SNPs) in the oxytocin receptor (OXTR) gene, suggesting a genetic component to infant-mother attachment. However, due to the genetic relatedness of infants and their mothers, it is difficult to separate the genetic effects of infants' OXTR genotype from the environmental effects of mothers' genotype possibly affecting their parental behavior. The apparent functional analogy between child-parent and dog-owner relationship, however, offers a way to disentangle the effects of these factors because pet dogs are not genetically related to their caregivers. In the present study we investigated whether single nucleotide polymorphisms of pet dogs' OXTR gene (-213AG,-94TC,-74CG) and their owners' OXTR gene (rs53576, rs1042778, rs2254298) are associated with components of dog-owner attachment. In order to investigate whether social-environmental effects modulate the potential genetic influence on attachment, dogs and their owners from two different countries (Austria and Hungary, N = 135 in total) were tested in a modified version of the Ainsworth Strange Situation Test (SST) and questionnaires were also used to collect information about owner personality and attachment style. We coded variables related to three components of attachment behavior in dogs: their sensitivity to the separation from and interaction with the owner (Attachment), stress caused by the unfamiliar environment (Anxiety), and their responsiveness to the stranger (Acceptance). We found that (1) dogs' behavior was significantly associated with polymorphisms in both dogs' and owners' OXTR gene, (2) SNPs in dogs' and owners' OXTR gene interactively influenced dog-human relationship, (3) dogs' attachment behavior was affected by the country of origin, and (4) it was related to their owners' personality as well as attachment style. Thus, the present study provides evidence, for the first time, that both genetic variation in the OXTR gene and various aspects of pet dogs' environmental background are associated with their attachment to their human caregivers.

Microsatellite Polymorphisms Adjacent to the Oxytocin Receptor Gene in Domestic Cats: Association with Personality?

A growing number of studies have explored the oxytocin system in humans and non-human animals, and some have found important genetic polymorphisms in the oxytocin receptor gene (OXTR) associated with the bonding system, social behaviors, and personality in several species. Although single nucleotide polymorphisms in OXTR have been well-examined in various species, microsatellites (or short tandem repeats) adjacent to OXTR have rarely been studied, despite some suggestions that microsatellite polymorphisms near genes might play a role in genetic transcription and translation. In this study, we surveyed microsatellites in the upstream, intron, and downstream regions of OXTR in domestic cats (Felis catus). We succeeded in amplifying 5 out of 10 regions, and recognized these five regions as polymorphic. We compared allele frequencies in these five regions between mongrel cats in Japan (n = 100) and cats of 10 pure breeds (n = 40). There were significant differences in allele frequencies between the two populations in all microsatellite regions. Additionally, the owners of mongrel cats answered a comprehensive personality questionnaire, and factor analysis extracted four factors (Openness, Friendliness, Roughness, and Neuroticism). We examined the association between the microsatellite genotypes, age, sex, neutering status, and personality scores. Compared to their counterparts, younger cats tended to score higher on Openness, male cats scored higher on Friendliness, and female and neutered cats scored higher on Roughness. When we divided the sample into three groups depending on the length of alleles, we found a marginally significant association between Friendliness and MS3. Additionally, we found a sex-mediated effect of genotypes in MS4 on Friendliness, resulting in different effects on females and males. Our findings that mongrel cats had longer alleles in MS3 and MS4 than purebred cats, and that those cats tended to score higher on Friendliness, supported the previous findings. However, future studies such as comparison between purebred cats with apparently different origin or personality are required to determine the association of genetic variants in the OXTR with personality.

Oxytocin as an Indicator of Psychological and Social Well-Being in Domesticated Animals: A Critical Review

Oxytocin is often portrayed as a hormone specific to social behavior, reflective of positive welfare states, and linked to mental states. Research on oxytocin in domesticated animal species has been few to date but is rapidly increasing (in dog, pig, cattle, sheep), with direct implications for animal welfare. This review evaluates the evidence for the specificity of oxytocin as an indicator of: 1. Social, 2. Positive, and 3. Psychological well-being. Oxytocin has most often been studied in socially relevant paradigms, with a lack of non-social control paradigms. Oxytocin research appears biased toward investigating positive valence, with a lack of control in valence or arousal. Oxytocin actions are modulated by the environmental and social contexts, which are important factors to consider. Limited evidence supports that oxytocin's actions are linked to psychological states; nevertheless whether this is a direct effect of oxytocin per se remains to be demonstrated. Overall, it is premature to judge oxytocin's potential as an animal welfare indicator given the few and discrepant findings and a lack of standardization in methodology. We cover potential causes for discrepancies and suggest solutions through appropriate methodological design, oxytocin sampling or delivery, analysis and reporting. Of particular interest, the oxytocinergic system as a whole remains poorly understood. Appreciation for the differences that social contact and group living pose in domesticated species and the way they interact with humans should be key considerations in using oxytocin as a psychosocial indicator of well-being.

Oxytocin and Opioid Receptor Gene Polymorphisms Associated with Greeting Behavior in Dogs

Meeting humans is an everyday experience for most companion dogs, and their behavior in these situations and its genetic background is of major interest. Previous research in our laboratory reported that in German shepherd dogs the lack of G allele, and in Border collies the lack of A allele, of the oxytocin receptor gene (OXTR) 19208A/G single nucleotide polymorphism (SNP) was linked to increased friendliness, which suggests that although broad traits are affected by genetic variability, the specific links between alleles and behavioral variables might be breed-specific. In the current study, we found that Siberian huskies with the A allele approached a friendly unfamiliar woman less frequently in a greeting test, which indicates that certain polymorphisms are related to human directed behavior, but that the relationship patterns between polymorphisms and behavioral phenotypes differ between populations. This finding was further supported by our next investigation. According to primate studies, endogenous opioid peptide (e.g., endorphins) receptor genes have also been implicated in social relationships. Therefore, we examined the rs21912990 of the OPRM1 gene. Firstly, we found that the allele frequencies of Siberian huskies and gray wolves were similar, but differed from that of Border collies and German shepherd dogs, which might reflect their genetic relationship. Secondly, we detected significant associations between the OPRM1 SNP and greeting behavior among German shepherd dogs and a trend in Border collies, but we could not detect an association in Siberian huskies. Although our results with OXTR and OPRM1 gene variants should be regarded as preliminary due to the relatively low sample size, they suggest that (1) OXTR and OPRM1 gene variants in dogs affect human-directed social behavior and (2) their effects differ between breeds.

The 'Feline Five': An exploration of personality in pet cats (Felis catus)

The idea of animals possessing personalities was once dismissed by the scientific community, but has since gained traction with evidence for potential application to improve captive animal management and welfare. Although domestic cats are popular companion animals, research has tended to overlook the value of personality assessment for management and care of pet cats. The aim of this study was to investigate personality in a large sample of pet cats with a view to understanding practical implications for pet cats in the home. Personality of 2,802 pet cats, from South Australia and New Zealand, was rated by their owners utilising a survey measuring 52 personality traits. Five reliable personality factors were found using principal axis factor analysis: Neuroticism, Extraversion, Dominance, Impulsiveness and Agreeableness. Implications for the 'Feline Five' are discussed in relation to their potential application to improving the management and welfare of pet cats. Highly Impulsive cats for example, may be reacting to something stressful in their environment, whereas cats with low Agreeableness scores, showing irritability may indicate underlying pain or illness. Thus, the need for a systematic and holistic approach to personality that includes both the individual pet cat and its environment is recommended, and opens the door to future interdisciplinary intervention.

Social Behavior of Pet Dogs Is Associated with Peripheral OXTR Methylation

Oxytocin is a key modulator of emotional processing and social cognitive function. In line with this, polymorphisms of genes involved in oxytocin signaling, like the oxytocin receptor (OXTR) gene, are known to influence social behavior in various species. However, to date, no study has investigated environmental factors possibly influencing the epigenetic variation of the OXTR gene and its behavioral effects in dogs. Pet dogs form individualized and strong relationships with their owners who are central figures in the social environment of their dogs and therefore might influence the methylation levels of their OXTR gene. Here we set out to investigate whether DNA methylation within the OXTR promoter region of pet dogs is linked to their owner's interaction style and to the social behavior of the dogs. To be able to do so, we collected buccal epithelial cells and, in Study 1, we used pyrosequencing techniques to look for differentially methylated CpG sites in the canine OXTR promoter region on a heterogeneous sample of dogs and wolves of different ages and keeping conditions. Four identified sites (at positions -727, -751, -1371, and -1383 from transcription start site) showing more than 10% methylation variation were then, in Study 2, measured in triplicate in 217 pet Border Collies previously tested for reactions to an adverse social situation (i.e., approach by a threatening human) and with available data on their owners' interaction styles. We found that CpG methylation was significantly associated with the behavior of the dogs, in particular with the likelihood that dogs would hide behind their owner or remain passive when approached by a threatening human. On the other hand, CpG methylation was not related to the owners' behavior but to dog sex (at position -1371). Our findings underpin the complex relationship between epigenetics and behavior and highlight the importance of including epigenetic methods in the analysis of dog behavioral development. Further research is needed to investigate which environmental factors influence the epigenetic variation of the OXTR gene.