Orienting asymmetries and physiological reactivity in dogs' response to human emotional faces.

Recent scientific literature shows that emotional cues conveyed by human vocalizations and odours are processed in an asymmetrical way by the canine brain. In the present study, during feeding behaviour, dogs were suddenly presented with 2-D stimuli depicting human faces expressing the Ekman's six basic emotion (e.g. anger, fear, happiness, sadness, surprise, disgust, and neutral), simultaneously into the left and right visual hemifields. A bias to turn the head towards the left (right hemisphere) rather than the right side was observed with human faces expressing anger, fear, and happiness emotions, but an opposite bias (left hemisphere) was observed with human faces expressing surprise. Furthermore, dogs displayed higher behavioural and cardiac activity to picture of human faces expressing clear arousal emotional state. Overall, results demonstrated that dogs are sensitive to emotional cues conveyed by human faces, supporting the existence of an asymmetrical emotional modulation of the canine brain to process basic human emotions.

Auditory lateralization of conspecific and heterospecific vocalizations in cats.

Auditory lateralization in response to both conspecific and heterospecific vocalizations (dog vocalizations) was observed in 16 tabby cats (Felis catus). Six different vocalizations were used: cat "purring," "meowing" and "growling" and dog typical vocalizations of "disturbance," "isolation" and "play." The head-orienting paradigm showed that cats turned their head with the right ear leading (left hemisphere activation) in response to their typical-species vocalization ("meow" and "purring"); on the other hand, a clear bias in the use of the left ear (right hemisphere activation) was observed in response to vocalizations eliciting intense emotion (dogs' vocalizations of "disturbance" and "isolation"). Overall these findings suggest that auditory sensory domain seems to be lateralized also in cat species, stressing the role of the left hemisphere for intraspecific communication and of the right hemisphere in processing threatening and alarming stimuli.

Right-nostril use during sniffing at arousing stimuli produces higher cardiac activity in jumper horses.

Lateralization in horses, Equus caballus, has been reported at both motor and sensory levels. Here we investigated left- and right-nostril use in 12 jumper horses freely sniffing different emotive stimuli. Results revealed that during sniffing at adrenaline and oestrus mare urine stimuli, horses showed a clear right-nostril bias while just a tendency in the use of the right nostril was observed during sniffing of other odours (food, cotton swab and repellent). Sniffing at adrenaline and urine odours was also accompanied by increasing cardiac activity and behavioural reactivity strengthening the role of the right hemisphere in the analysis of intense emotion and sexual behaviour.

Laterality and performance of agility-trained dogs.

Correlations between lateralised behaviour and performance were investigated in 19 agility-trained dogs (Canis familiaris) by scoring paw preference to hold a food object and relating it to performance during typical agility obstacles (jump/A-frame and weave poles). In addition, because recent behavioural studies reported that visual stimuli of emotional valence presented to one visual hemifield at a time affect visually guided motor responses in dogs, the possibility that the position of the owner respectively in the left and in the right canine visual hemifield might be associated with quality of performance during agility was considered. Dogs' temperament was also measured by an owner-rated questionnaire. The most relevant finding was that agility-trained dogs displayed longer latencies to complete the obstacles with the owner located in their left visual hemifield compared to the right. Interestingly, the results showed that this phenomenon was significantly linked to both dogs' trainability and the strength of paw preference.

Catecholamine plasma levels, IFN-γ serum levels and antibodies production induced by rabies vaccine in dogs selected for their paw preference.

To explore the possible role of the sympathetic nervous activity in the asymmetrical crosstalk between the brain and immune system, catecholamine (E, NE) plasma levels, Interferon-γ (IFN-γ) serum levels and production of antibodies induced by rabies vaccine in dogs selected for their paw preference were measured. The results showed that the direction of behavioural lateralization influenced both epinephrine levels and immune response in dogs. A different kinetic of epinephrine levels after immunization was observed in left-pawed dogs compared to both right-pawed and ambidextrous dogs. The titers of antirabies antibodies were lower in left-pawed dogs than in right-pawed and ambidextrous dogs. Similarly, the IFN-γ serum levels were lower in left-pawed dogs than in the other two groups. Taken together, these findings showed that the left-pawed group appeared to be consistently the different group stressing the fundamental role played by the sympathetic nervous system as a mechanistic basis for the crosstalk between the brain and the immune system.

An Observational Study of Skeletal Malformations in Four Semi-Intensively Reared Carp Species.

Cyprinids include some of the most widely farmed freshwater species. The aim of this study was to assess the incidence of skeletal malformations in carp species reared in semi-intensive systems in Albania: common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and bighead carp (Hypophthalmichthys nobilis). The common carp fingerlings had a mean total length of 28.9 ± 5.0 mm; the frequencies of individuals with at least one anomaly and at least one severe anomaly were 79.2% and 43.4%, respectively. The silver carp juveniles had a mean total length of 21.6 ± 2.1 mm; the frequencies of individuals with at least one anomaly and one severe anomaly were 93.1% and 57.5%, respectively. The grass carp fry had a mean total length of 33.5 ± 2.6 mm; all the analyzed specimens showed almost one anomaly and 86.4% showed at least one severe anomaly. The bighead carp juveniles had a mean total length of 34.4 ± 5.7 mm; the frequencies of individuals with at least one anomaly and at least one severe anomaly were 95.0% and 62.5%, respectively. The development of a more suitable feeding protocol for herbivorous species and the setting up of more efficient broodstock management protocols are suggested to reduce the high incidence of skeletal malformations.

Detour behaviour in attack-trained dogs: left-turners perform better than right-turners.

Detour behaviour was investigated in attack-trained dogs faced with a "U"-shaped vertical barrier behind which a figurant (target) was located. Left-turners took less time to detour the barrier than right-turners. The most logical explanation for the lateral asymmetries observed in dogs' detour behaviour is to assume that they reflect preferential use of the right or the left eye in visual analysis of the target. Given that the lateral field of each eye of dogs projects mainly to the contralateral side of the brain, shorter latencies to solve the task observed in left-turners (right visual hemifield) with respect to right-turners (left visual hemifield) are consistent with specialisation of the left hemisphere in prey-catching behaviour. Overall our results supported previous evidence that cerebral lateralisation in vertebrates can directly affect visually guided motor responses and have practical implications for personnel involved in the selection of dogs trained specifically to assist police and other law-enforcement personnel in their work.

Effect of Attentional Bias on the 3D Rotated Objects Recognition Ability of Dogs.

The ability to recognize rotated objects has been widely reported in the animal kingdom. Studies on animal and human spatial cognition highlighted the importance of visuo-spatial cognitive capability for surviving in a dynamic world. Although domestic animals are frequently involved in activities requiring a high level of visuo-spatial ability, currently, little is known about their visuo-spatial skills. To investigate this issue, we trained six dogs to discriminate between 3D objects (using a modified version of the Shepard-Metzler task) that were then reproduced digitally on a computer. We found that the dogs recognized three-dimensional objects and their rotated versions (45° and 180°) more easily when presented on the left side of the screen, suggesting right hemisphere superiority in the control of visuo-spatial functions. Moreover, we report inter-individual variability in their performance in the visuo-spatial task. Our preliminary results suggest that dogs could use a rotational invariance process for the discrimination of 3D rotated shapes that deserves further investigation.

Relationship between asymmetric nostril use and human emotional odours in cats.

Cat social behaviour and cognition has received a growing interest during the last decades. Recent studies reported that cats efficiently engage in interspecific communication with humans and suggest that cats are sensitive to human emotional visual and auditory cues. To date, there is no evidence on the social and informative role of human emotional odours, which may affect human-cat communication. In this study, we presented cats with human odours collected in different emotional contexts (fear, happiness, physical stress and neutral) and evaluated the animals' behavioural responses. We found that "fear" odours elicited higher stress levels than "physical stress" and "neutral", suggesting that cats perceived the valence of the information conveyed by "fear" olfactory signals and regulate their behaviour accordingly. Moreover, the prevalent use of the right nostril (right hemisphere activation) with the increase of stress levels, particularly in response to "fear" odours, provides first evidence of lateralized emotional functions of olfactory pathways in cats.

Reproductive Maturation of Meagre Argyrosomus regius (Asso, 1801) Reared in Floating Cages.

The meagre Argyrosomus regius (Asso, 1801) is a promising aquaculture species that shows reproductive dysfunctions when reared in tanks. The aim of this study was to assess the capacity of meagre, reared in cages under routine farming conditions, to mature gonads and reproduce spontaneously. Meagre adults, reared in a fish farm located in the Gulf of Taranto (Italy), were sampled from March to July 2021. The gonadosomatic index and sex steroid plasma concentrations increased from March-April to June, and then decreased in July. In March-April, most of the females showed perinucleolar or cortical alveoli oocytes as the most advanced stages in the ovaries, and most of the males had testes at early spermatogenesis stage. In June, most of the sampled females had oocytes at late vitellogenesis or early post-vitellogenesis stages, and males had seminiferous tubules filled with spermatozoa. In July, most of the females had signs of previous spawning, and males showed scarce amounts of luminal spermatozoa. The present study demonstrated the capacity of meagre, reared in sea cages under commercial conditions, to carry out gametogenesis and spontaneously release gametes. Meagre reproduction, under routine farming conditions, may represent an opportunity for the expansion of meagre aquaculture production.

Are temporal features crucial acoustic cues in dog vocal recognition?

To investigate the perceptual mechanisms underlying conspecific vocal recognition in canine species, eighteen dogs were presented with playbacks of normal and reversed versions of typical dog vocalizations. Auditory perception was analysed using the head-turn paradigm, a non-invasive technique extensively employed to study hemispheric specializations for processing conspecific vocalizations in primates. The results revealed that dogs usually turn their heads with the right ear leading (left hemisphere activation) in response to the forward version of their typical calls, and with either no bias and the left ear leading (right hemisphere activation) in response to the reversed call versions. Overall, our findings suggest that temporal features are determinant auditory cues for call sound recognition in dogs, and support earlier findings of the role of the left hemisphere in the analyses of intraspecific communication.

Facial asymmetry in dogs with fear and aggressive behaviors towards humans.

There is now scientific evidence that, in dogs, distinctive facial actions are produced in response to different emotionally-arousing stimuli suggesting a relationship between lateralized facial expressions and emotional states. Although in humans, relationships between facial asymmetry and both emotional and physiological distress have been reported, there are currently no data on the laterality of dogs' facial expressions in response to social stimuli with respect to canine behavioral disorders. The aim of the present work was to investigate the facial asymmetries of dogs with fear and aggressive behavior towards humans during two different emotional situations: (1) while the dogs were alone in the presence of their owners and (2) during the approach of an unfamiliar human being. Overall, our results demonstrated high levels of asymmetries in facial expressions of dogs displaying fear and aggressive behaviors towards humans indicating that measuring facial asymmetries in dogs could prove to be a useful non-invasive tool for investigating physiology-based behavioral disorders.

The Potential Impact of a Dog Training Program on the Animal Adoptions in an Italian Shelter.

One of the main concerns of the human-dog relationship is today associated with the quality life inside the kennels, which are very often regarded as animal dump where dogs are exiled, representing a burden on society. In the present study we sought to investigate the importance of performing an appropriate behavioral program on the adoption chances within an Italian shelter, near Naples (Ottaviano). In this respect, we enrolled 555 adopted dogs of different ages, who followed a tailored-4-month lasting training program between 2018 and 2020. Once entered there, they were carefully examined by the veterinary behaviorist, and directed towards a suited training program, to improve living conditions. We documented a higher number of both adult and senior dogs who left the kennel and were adopted, compared to the age-matched untrained animals (n = 479), housed in the same kennel from 2015 to 2017. Taken together, the present data highlight an important role for training in improving the natural attitudes of the companion dogs, thus pointing towards a better human-animal bond.

Motivations of Human Helping Behavior towards Dogs.

Human-dog interactions have a positive effect on human sociality and health. The relationship with dogs helps humans to cope with stress during an emotionally challenging period, such as the COVID-19 pandemic. During this period, a growing global interest in pets has been registered, including the volunteering for shelter/stray dog protection. However, a considerable increase of human dysfunctional interventions toward dogs has been observed in Southern Italy. In this study, we investigated the psychological characteristics of humans volunteering at animal shelter or engaged in stray dog protection. The effect of psychological training and education about dog ethological needs on volunteers' helping behavior was also analyzed. We report that the intervention can improve volunteers' physiological features and, consequently, may enhance human management and dog welfare.

Volumetric assessment of cerebral asymmetries in dogs.

In the present study we quantified volumetric brain asymmetries from computed tomography (CT) scans in 12 healthy dogs, using a semi-automated technique for assessing in vivo structure asymmetry. Volumetric assessment of asymmetrical cerebral lateral ventricle (ALV) was also investigated. Our results showed that seven dogs exhibited a right hemisphere significantly greater than the left, two dogs had a left-greater-than-right hemisphere asymmetry, and finally two dogs displayed no significant brain volumetric asymmetry. This right-biased hemispheric asymmetry supports data reported previously using post-mortem morphological studies in both dogs and other mammalian species.

Emotions and Dog Bites: Could Predatory Attacks Be Triggered by Emotional States?

Dog biting events pose severe public health and animal welfare concerns. They result in several consequences for both humans (including physical and psychological trauma) and the dog involved in the biting episode (abandonment, relocation to shelter and euthanasia). Although numerous epidemiological studies have analyzed the different factors influencing the occurrence of such events, to date the role of emotions in the expression of predatory attacks toward humans has been scarcely investigated. This paper focuses on the influence of emotional states on triggering predatory attacks in dogs, particularly in some breeds whose aggression causes severe consequences to human victims. We suggest that a comprehensive analysis of the dog bite phenomenon should consider the emotional state of biting dogs in order to collect reliable and realistic data about bite episodes.

Cortisol Levels of Shelter Dogs in Animal Assisted Interventions in a Prison: An Exploratory Study.

Previous studies regarding the Animal Assisted Interventions (AAI) have mainly focused on the beneficial effects of human-animal interactions on human health; whereas the impact of such activities on the welfare of the animals involved has received limited attention. So far, few studies have addressed this issue by evaluating the physiological and behavioral reactions of therapy dogs during the interventions. The aim of this study was to evaluate the potential effect of AAI on the cortisol levels of shelter dogs. Five dogs participated in weekly AAI working activities with adult inmates held at a prison of the South of Italy for two months. Saliva samples were collected every two weeks in three conditions: at the kennel (baseline), after transportation and at the end of the working sessions. The results revealed a significant decrease in the cortisol baseline at the end of the AAI program, suggesting that the activities carried out with humans and in a different environment could improve the welfare of dogs housed in kennels. Moreover, we found that transportation significantly increased subjects' cortisol levels, suggesting that it is a critical phase that deserves particular care.

Odour-Evoked Memory in Dogs: Do Odours Help to Retrieve Memories of Food Location?

The ability of odors to spontaneously trigger specific memories has been widely demonstrated in humans. Although increasing evidence support the role of olfaction on dogs' emotions and cognitive processes, very little research has been conducted on its relationship with memory in this species. The present study aimed at investigating the role of olfaction in the recall of detailed memories originally formed in the presence of a specific odor (i.e., vanilla). To test this, three groups of participants were trained with the same spatial learning task while a specific odor (i.e., vanilla) was dispersed in the testing room. Subjects were then divided in three experimental groups and after 24 h delay, they were presented with the same spatial task. The first group (Group 1) performed the task in the presence of a novel odor (i.e., control), whereas the second (Group 2) and the third group (Group 3) carried out the test in the presence of the vanilla odor and no odor (Group 3), respectively. After a brief delay, the test was presented again to the three groups of dogs: subjects of Group 1 were now tested in the presence of the vanilla odor, whereas the Group 2 was tested with the control odor. The Group 3 received no odor in both tests. A significant improvement of dogs' performance was registered in the control-vanilla odors condition (Group 1), suggesting that the exposure to the odor presented at the encoding time would prompt the recall of spatial memories in dogs.

Emotion Recognition in Cats.

Recent studies demonstrated that cats form social bonds with both conspecifics and humans. One of the key factors regulating social interactions is the transfer of emotions between the individuals. The present study aimed at investigating cats' spontaneous ability to match acoustic and visual signals for the recognition of both conspecific and human emotions. Different conspecific (cat "purr" and "hiss") and heterospecific (human "happiness" and "anger") emotional stimuli were presented to the tested population using a cross-modal paradigm. Results showed that cats are able to cross-modally match pictures of emotional faces with their related vocalizations, particularly for emotions of high intensity. Overall, our findings demonstrate that cats have a general mental representation of the emotions of their social partners, both conspecifics and humans.

Human-Animal Relationship Dysfunction: A Case Study of Animal Hoarding in Italy.

"Animal hoarding" or "compulsive hoarding of animals" is a psychiatric disease, which has important social implications and a profound influence on animal welfare. To date, this phenomenon has been little investigated and largely unexplored. The present study aims to systematically describe a case of animal hoarding, which remains unresolved. The report refers to a case of a woman suffering from animal hoarding that emerged in 2005. From March 2014 to December 2019, 450 animals were seized over nine different occasions. This disease had significant implications on the welfare of the animals collected, which lived in poor housing and hygiene conditions that frequently led to their death. Since animal hoarding cases involve sanitary, legal, and veterinary aspects, we believe that a multidisciplinary approach is necessary in order to prevent a recurrence and a new accumulation of animals. A holistic approach should be taken according to the One Health principle that involves different stakeholders at every level in order to adopt an efficient solution.