No abstract

Previous studies have demonstrated similarities in gazing behaviour of dogs and humans, but comparisons under similar conditions are rare, and little is known about dogs' visual attention to social scenes. Here, we recorded the eye gaze of dogs while they viewed images containing two humans or dogs either interacting socially or facing away: the results were compared with equivalent data measured from humans. Furthermore, we compared the gazing behaviour of two dog and two human populations with different social experiences: family and kennel dogs; dog experts and non-experts. Dogs' gazing behaviour was similar to humans: both species gazed longer at the actors in social interaction than in non-social images. However, humans gazed longer at the actors in dog than human social interaction images, whereas dogs gazed longer at the actors in human than dog social interaction images. Both species also made more saccades between actors in images representing non-conspecifics, which could indicate that processing social interaction of non-conspecifics may be more demanding. Dog experts and non-experts viewed the images very similarly. Kennel dogs viewed images less than family dogs, but otherwise their gazing behaviour did not differ, indicating that the basic processing of social stimuli remains similar regardless of social experiences.

The neuropeptide oxytocin plays a critical role in social behavior and emotion regulation in mammals. The aim of this study was to explore how nasal oxytocin administration affects gazing behavior during emotional perception in domestic dogs. Looking patterns of dogs, as a measure of voluntary attention, were recorded during the viewing of human facial expression photographs. The pupil diameters of dogs were also measured as a physiological index of emotional arousal. In a placebo-controlled within-subjects experimental design, 43 dogs, after having received either oxytocin or placebo (saline) nasal spray treatment, were presented with pictures of unfamiliar male human faces displaying either a happy or an angry expression. We found that, depending on the facial expression, the dogs’ gaze patterns were affected selectively by oxytocin treatment. After receiving oxytocin, dogs fixated less often on the eye regions of angry faces and revisited (glanced back at) more often the eye regions of smiling (happy) faces than after the placebo treatment. Furthermore, following the oxytocin treatment dogs fixated and revisited the eyes of happy faces significantly more often than the eyes of angry faces. The analysis of dogs’ pupil diameters during viewing of human facial expressions indicated that oxytocin may also have a modulatory effect on dogs’ emotional arousal. While subjects’ pupil sizes were significantly larger when viewing angry faces than happy faces in the control (placebo treatment) condition, oxytocin treatment not only eliminated this effect but caused an opposite pupil response. Overall, these findings suggest that nasal oxytocin administration selectively changes the allocation of attention and emotional arousal in domestic dogs. Oxytocin has the potential to decrease vigilance toward threatening social stimuli and increase the salience of positive social stimuli thus making eye gaze of friendly human faces more salient for dogs. Our study provides further support for the role of the oxytocinergic system in the social perception abilities of domestic dogs. We propose that oxytocin modulates fundamental emotional processing in dogs through a mechanism that may facilitate communication between humans and dogs.

Summary Background Severe malocclusions appear in up to 20 per cent of the population. Many neuropsychiatric diseases are likely to have a neurodevelopmental, partially genetic background with their origins as early as fetal life. However, the possible relationship between neurodevelopmental disorders and severe malocclusions is unclear. The aim of this study was in a population-based setting (270 000 inhabitants) to investigate whether patients with severe malocclusions have more mental and behavioural disorders and growth or speech problems than controls without severe malocclusion. Material and Methods The study group consisted of patients from the Espoo Health Care Center, Finland, born in year 2000, who were retrospectively screened for their medical and dental records, including their possible mental and behavioural disorders (i.e. attention deficit hyperactivity disorder, Asperger’s syndrome, autism, mood disorder, or broadly defined behavioural abnormalities, learning problems, mental disorders, sleep disturbances, anxiety symptoms, depressive symptoms, and eating-related symptoms) and their need of orthodontic treatment according to the Treatment Priority Index (TPI). The study group consisted of a severe malocclusion group (n =1008; TPI 8–10) and a control group (n = 1068) with no severe malocclusion (TPI 0–7). Results Patients with severe mandibular retrognatia (P < 0.000), lip incompetence (P = 0.006), or neurodevelopmental disorders (mental and behavioural; P = 0.002) were found to have significantly more speech problems than the controls. The patients with severe malocclusions were leaner, that is, body mass index (kg/m2) <17, underweight; 17–25, normal weight; >25, overweight) than controls (P = 0.003), and underweight patients had a significant association with retrognathic maxilla (P < 0.000) compared to normal or overweight patients. No significant relationship between neurodevelopmental disorders and severe malocclusions, that is, retrognatia of maxilla, hypodontia, and severe dental crowding was observed. Conclusion Our results indicate that patients with severe mandibular retrognatia, lip incompetence, or neurodevelopmental disorders were found to have significantly more speech problems than controls. During orthodontic treatment of patients with severe malocclusion, special attention should be paid to patients with severe mandibular retrognatia, lip incompetence, and speech problems to detect signs of possible neurodevelopmental disorders and record if potential follow-up measures are in place.

Fear of loud noises is a common welfare problem in pet dogs. Commercial treatment vests have been tested on dogs to relieve noise phobia, and peripheral oxytocin has been suggested to be one of the stressrelieving mediators. The effect of vests has not, however, been tested in a controlled situation. We tested whether individually customized vests, have an effect on behaviour of severely noise phobic dogs in a double-blinded experiment, where dogs are exposed to loud noises. We also investigated the possible effect of pressure by using two types of vests; a deep pressure vest (DEEP, c. 10-12 mmHg) and a light pressure vest (LIGHT, c. 2-3 mmHg). In addition to behaviour, we studied if the pressure vest has an effect on urine oxytocin level and on saliva cortisol levels. A total of 28 dogs (2-11 years), both female (18) and male (10), were recruited via an ongoing study on the genetic background of noise sensitivity by the Finnish Canine Genetic Research Group. Each dog was tested three times either without vest (CONTROL) or with DEEP or LIGHT vests in a semi-randomized order. The dogsí behaviour was video recorded for 6 min, including three 2 min intervals: pre-noise, noise (70-73 dB firework sound) and recovery. Behavioural parameters included activity, body and tail postures, vocalization, and time spent near owner. Saliva samples were collected twice before and twice after the noise test. Urine samples for oxytocin analyses were collected when the deep pressure vest was first fitted: before dressing the dog and 30 min later. The DEEP vest reduced the lying time of the dogs during the noise interval. During the noise interval total lying time with any vest correlated positively with saliva cortisol, measured after noise interval, indicating that the increased lying time was a sign of a higher stress level in the dogs. Wearing either vests increased the time the dogs spent near their owners during noise interval. Time spent near the owner when wearing the DEEP vest during the recovery interval correlated positively with the urine oxytocin. These results indicate oxytocin might be related to the dogís tendency to seek owner support and the vests might effect this behaviour positively. We did not find a clear therapeutic effect of using pressure vests in noise phobic dogs. However, our results indicate the pressure vest might reduce the acute stress reaction and speed up the recovery after stress.