Claudio Sighieri

Post-conflict friendly reunion in a permanent group of horses (Equus caballus).

Gregarious animals living in permanent social groups experience intra-group competition. Conflicts over resources can escalate into costly aggression and, in some conditions, non-dispersive forms of conflict resolution may be favoured. Post-conflict friendly reunions, hence reconciliation, have been described in a variety of species. The aim of this study was to explore, for the first time, the occurrence of reconciliation in a group of domestic horses (Equus caballus) and learn more about strategies used to maintain group cohesion. The behaviour of seven horses living as permanent group in an enclosure for at least 2 years was observed by video for 108h from June to August 2007. We used a Post-Conflict/Matched Control method to assess the existence of reconciliation and third-party affiliation. Behaviours recorded Post-Conflict, or during Matched Control periods, were classified as affiliative based on previous descriptions of visual communication patterns in horses. The proportion of attracted pairs over total post-conflict situations was significantly greater than the proportion of dispersed pairs, both during dyadic interactions (p<0.001) and during triadic interactions (p=0.002). The results of the present study show that both dyadic reconciliation and third-party post-conflict affiliative interactions form important social mechanisms for managing post-conflict situations in horses.

Behaviour of mean erythrocyte volume during submaximal treadmill exercise in the horse

Abstract: The aim of this work was to study the role of spleen contraction in the modification of circulating erythrocyte mean volume during treadmill exercise in the horse. Red blood cells count (RBC), haematocrit (Hct), haemoglobin (Hgb), mean cellular volume (MCV), mean cellular haemoglobin (MCH), mean cellular haemoglobin concentration (MCHC) and red cell distribution width (RDW) were evaluated in five Haflinger mares performing a submaximal incremental test on the treadmill. Blood was collected every minute during the trial without stopping the treadmill. Significant changes of all measured parameters, except for MCH, have been observed. Hct values increased significantly from the 2nd minute from the start of the test. MCV and MCHC values were significantly different from their basal values from the 6th minute of exercise, with MCV being increased and MCHC decreased, suggesting cellular swelling. Hct modifications during brief submaximal exercise have been shown to be mainly and directly related to mobilization of the pool of red blood cells stored in the spleen. However, the evidence in this study of different times of onset of changes between Hct and erythrocyte indices (MCV and MCHC) suggests that exercise-induced alterations in red cell indices are not related to spleen emptying.

Detour behaviour in horses (Equus caballus)

The objective of this study was to investigate the ability of horses (Equus caballus) to detour around symmetric and asymmetric obstacles. Ten female Italian saddle horses were each used in three detour tasks. In the first task, the ability to detour around a symmetrical obstacle was evaluated; in the second and third tasks subjects were required to perform a detour around an asymmetrical obstacle with two different degrees of asymmetry. The direction chosen to move around the obstacle and time required to make the detour were recorded. The results suggest that horses have the spatial abilities required to perform detour tasks with both symmetric and asymmetric obstacles. The strategy used to perform the task varied between subjects. For five horses, lateralized behaviour was observed when detouring the obstacle; this was consistently in one direction (three on the left and two on the right). For these horses, no evidence of spatial learning or reasoning was found. The other five horses did not solve this task in a lateralized manner, and a trend towards decreasing lateralization was observed as asymmetry, and hence task difficulty, increased. These non-lateralized horses may have higher spatial reasoning abilities.

Effect of aging on behavioural and physiological responses to a stressful stimulus in horses (Equus caballus)

In humans the expression of emotions varies with aging, but for domestic animals we have little information on this subject. Our aim was to verify the influence of aging (life experience) on the expression of emotions in horses (Equus caballus) in reaction to a stressful stimulus. A total of 98 horses were subjected to the sudden inflation of a balloon in a familiar environment for a period of 5 min, on the assumption that this would induce a negative state. When the balloon was inflated, heart rate variability as an indicator of stress response was monitored. Behaviour related to emotional expression (latency of onset, frequency and length of looking and exploration, frequency of avoidance) was also monitored. The younger horses showed a significantly higher frequency of avoidance as well as greater exploratory activity, while the older subjects were less behaviourally responsive and showed a shift toward control by the sympathetic nervous system, as indicated by lower heart rate variability. The results suggest that aging influences the behaviour and physiology of emotional expression to stressful stimuli in horses. Knowing the effect of aging on stress response could be a critical factor in understanding equine welfare and the development of behavioural patterns.

Influence of emotional balance during a learning and recall test in horses (Equus caballus)

Modern day horse-human relationships entail different types of sport and riding activities, which all require learning. In evaluating the interaction between learning and emotions, studying normal coping strategies or adaptive responses to the surroundings is critical. 34 horses were involved in a cognitive test, in the absence of physical effort, to analyze performance, as well as physiological and behavioral responses related to learning, memorization and recall, associated to the capacity to reverse a learned model. Synthetic Equine Appeasing Pheromone (EAP) was used in 17 horses in order to modulate their emotional state and evaluate differences in cognitive-emotional response during cognitive effort in comparison to the control group (placebo group). Both groups showed statistically significant changes in heart rate during the test, indicating emotional and physio-cognitive activation. The EAP group produced fewer errors and made more correct choices, showing behaviors related to increased attention, with less influence from environmental stimuli. The capacity to learn to learn, as shown in the bibliography, allows animals to establish conceptual learning, when a normal or positive emotional state (in this case modulated by semiochemicals) is used to control limbic system activation and, consequently, decrease stressful/fearful reactions, resulting in better learning capacities during the cognitive test.

Application of a constant blood withdrawal method in equine exercise physiology studies

The aim of the present study was to test a constant blood withdrawal method (CBWM) to collect blood samples from horses during treadmill exercise. CBWM was performed in 4 Standardbreds and 5 Haflinger horses. A peristaltic pump was used to control blood aspiration from an i.v. catheter via an extension line. Blood was collected using an automatic fractions collector, with a constant delay time between the drawing of blood and sample collection. Blood withdrawal using CBWM was made during a treadmill standardised exercise test (SET). A blood flow of 12 m/min was used and samples collected every 60 s during the entire period of exercise. The volume of blood collected in each sample tube was 12.1+/-0.2 ml, with a delay time of mean +/- s.d. 25.3+/-0.8 s. Plasma lactate kinetics based on measurement of lactate in each fraction showed an exponential increase during the first 13 min of exercise (10.5 min of SET and 2.5 min recovery). The peak plasma lactate concentration was observed between 2.5 and 5.5 min after the end of SET. CBWM permits the kinetics of lactate and other blood-borne variables to be studied over time. This method could be a valuable aid for use in studying equine exercise physiology.

Analysis of the intraspecific visual communication in the domestic dog (Canis familiaris): A pilot study on the case of calming signals

ABSTRACT Studying the signaling of domestic dogs is crucial to have a better understanding of this species. The aim of this study was to scientifically assess if the behaviors called calming signals have a communicative and a calming function (i.e., de‐escalating the aggressive display in the other dog). Twenty‐four dogs, 12 females and 12 males, acted as senders; they were observed for the display of the behaviors considered by Rugaas (2006) as calming signals (CSs). The behavior of each sender dog was analyzed during four 5‐minute off‐leash encounters, in which the dog met 4 different recipients, respectively: a familiar and an unfamiliar dog of the same sex; a familiar and an unfamiliar dog of the other sex. The display and trend of aggressive behaviors in recipient dogs was also analyzed. In total, 2,130 CSs were observed. Some behaviors were displayed more often than others, especially, head turning, licking nose, freezing, and turning away. It was statistically more likely that the CSs were sent while the 2 dogs were interacting rather than when there was no interaction (χ2 = 836.155; P < 0.001), suggesting these signals have a communicative role. The statistical analysis revealed that a higher number of signals were observed during meetings between unfamiliar dogs (χ2 = 108.721; P < 0.001). Head turning, nose licking, freezing, making him/herself smaller, and paw lifting were displayed by the sender statistically more frequently while interacting with unfamiliar dogs. Licking the other dogs mouth was more commonly directed toward familiar dogs. In total, 109 episodes of aggressive behaviors were displayed by the recipient dogs. Aggressive episodes were never preceded by the display of a calming signal from the other dog. In 67.0% of cases (N = 73), at least 1 CS was displayed by the sender dog after having received an aggressive behavior from the recipient. When CSs were displayed after an aggressive interaction, in 79.4% of cases (N = 58), there was a de‐escalation in the aggressive display of the other dog. It was statistically less likely that the intensity of aggressive behaviors increased (5.5%/N = 4) or remained unvaried (15.1%/N = 11; χ2 = 13.17; P < 0.001). These findings suggest that these CSs indeed may have a role in social facilitation and preventing further aggressive behaviors.

Brief note about plasma catecholamines kinetics and submaximal exercise in untrained standardbreds

Four untrained standardbred horses performed a standardized exercise test on the treadmill and an automated blood collection system programmed to obtain blood samples every 15 s was used for blood collection in order to evaluate the kinetics of adrenaline and noradrenaline. The highest average values obtained for adrenaline and noradrenaline were 15.0 +/- 3.0 and 15.8 +/- 2.8 nmol/l respectively, with exponential accumulation of adrenaline (r = 0.977) and noradrenaline (r = 0.976) during the test. Analysis of the correlation between noradrenaline and adrenaline for each phase of the test shows that correlation coefficient decreases as the intensity of exercise increases (from r = 0.909 to r = 0.788). This suggests that during submaximal exercise, the process for release, distribution and clearance of adrenaline into blood circulation differs from that of noradrenaline.

Potential involvement of ubiquinone in myotonic dystrophy pathophysiology: new diagnostic approaches for new rationale therapeutics

Abstract An impairment of mitochondrial function may contribute to the pathophysiology of myotonic dystrophy (MyD). Coenzyme Q10 (CoQ10) deficiency has been previously observed, even if in an restricted sample of patients. The aim of this investigation was to obtain more information about coenzyme Q10 and its relationships to the aerobic metabolism in a group of MyD patients. Serum CoQ10 appeared significantly reduced with respect to normal controls: 0.93±0.22 vs. 1.58±0.28 μg/ml (p<0.05). Moreover, the results demonstrated an inverse tendency between CoQ10 levels and the CTG expansion degree. Basal blood lactate levels were significantly higher than controls (p<0.05). A borderline inverse correlation between CoQ10 and lactate, corresponding to lactate threshold, was found. These data suggest a possible role of CoQ10 in the pathogenesis of MyD, which may be mediated by mechanisms of cellular damage common to the oxidative pathway. Therapeutic strategies may be devised by virtue of this rationale.

Consistency and flexibility in solving spatial tasks: Different horses show different cognitive styles

Individual animals vary in their behaviour and reactions to novel situations. These differences may extend to differences in cognition among individuals. We tested twenty-six horses for their ability to detour around symmetric and asymmetric obstacles. All of the animals were able to get around the barrier to reach a food target, but varied in their approach. Some horses moved slowly but were more accurate in choosing the shortest way. Other horses acted quickly, consistently detoured in the same direction, and did not reliably choose the shortest way. The remaining horses shifted from a faster, directionally consistent response with the symmetric barrier, to a slower but more accurate response with the asymmetric barrier. The asymmetric barrier induced a reduction in heart rate variability, suggesting that this is a more demanding task. The different approaches used to solve the asymmetric task may reflect distinct cognitive styles in horses, which vary among individuals, and could be linked to different personality traits. Understanding equine behaviour and cognition can inform horse welfare and management.