Abstract: Six ponies were used to investigate the effect of tolazoline antagonism of detomidine on physiological responses, behavior, epinephrine, norepinephrine, cortisol, glucose, and free fatty acids in awake ponies. Each pony had a catheter inserted into a jugular vein 1 hour before beginning the study. Awake ponies were administered detomidine (0.04 mg/kg intravenously [i.v.]) followed 20 minutes later by either tolazoline (4.0 mg/kg i.v.) or saline. Blood samples were drawn from the catheter 5 minutes before detomidine administration (baseline), 5 minutes after detomidine administration, 20 minutes before detomidine administration which was immediately before the administration of tolazoline or saline (time [T] = 0), and at 5, 30, and 60 minutes after injections of tolazoline or saline (T = 5, 30, and 60 minutes, respectively). Compared with heart rate at T = 0, tolazoline antagonism increased heart rate 45% at 5 minutes. There was no difference in heart rate between treatments at 30 minutes. Blood pressure remained stable after tolazoline, while it decreased over time after saline. Compared with concentrations at T = 0, tolazoline antagonism of detomidine in awake ponies resulted in a 55% increase in cortisol at 30 minutes and a 52% increase in glucose at 5 minutes. The change in free fatty acids was different for tolazoline and saline over time. Free fatty acids decreased after detomidine administration. Free fatty acids did not change after saline administration. After tolazoline administration, free fatty acids increased transiently. Tolazoline tended to decrease sedation and analgesia at 15 and 60 minutes postantagonism. Antagonism of detomidine-induced physiological and behavioral effects with tolazoline in awake ponies that were not experiencing pain appears to precipitate a stress response as measured by cortisol, glucose, and free fatty acids. If antagonism of an alpha-agonist is contemplated, the potential effect on hormones and metabolites should be considered.

Abstract: Social relationships significantly influence physiology and behavior, including the hypothalamo–pituitary–adrenal axis, anxiety, and mental
health. Disruption of social bonds through separation or death often results in profound grieving, depression, and physical illness. As the
monogamous prairie vole forms enduring, selective pair bonds with the mating partner, they provide an animal model to study the
physiological consequences of pair bonding and, thus, the loss of the bonded partner. Male prairie voles were paired with a novel female
or male sibling. After 5 days, half of the males of each group were separated from the partner. Elevated plus-maze, forced swim, and tail
suspension tests were used to assess anxiety-like and passive stress-coping behaviors indicative of depressive-like behavior. Following 4
days of separation from the female but not the male partner, experimental males displayed increased passive stress-coping. This effect
was abolished by long-term intracerebroventricular infusion of a nonselective corticotropin-releasing factor (CRF) receptor antagonist
without disrupting the bond itself. Both CRF type 1 and 2 receptors were involved in the emergence of passive stress-coping behavior.
Furthermore, pairing with a female was associated with elevated CRF mRNA in the bed nucleus of the stria terminalis, and partner loss
elicited a pronounced increase in circulating corticosteroid and adrenal weight. We speculate that the CRF system may mediate an
aversive affect following separation from the female partner, which may facilitate proximity seeking between the pair-bonded individuals.
Hence, the prairie vole model may provide insights into brain mechanisms involved in the psychopathological consequences of partner
loss.

Abstract: Socially acquired predator avoidance is a phenomenon in which individuals acquire an avoidance response towards an initially neutral stimulus after they have experienced it together with the antipredator signals of social companions. Earlier research has established that alarm calls used for intraspecific communication are effective stimuli for triggering acquisition. However, animals produce a large range of other antipredator responses that might engage antipredator learning. Here, I examine the effects of conspecific distress calls, a signal that is produced by birds when restrained by a predator, and that appears to be directed towards predators, rather than conspecifics, on predator avoidance learning in Indian mynahs, Acridotheres tristis. Distress calls reflect high levels of alarm in the caller and should, therefore, mediate robust learning. Experiment 1 revealed that subjects performed higher rates of head movements in response to a previously unfamiliar avian mount after it had been presented simultaneously with playbacks of conspecific distress vocalizations. Experiment 2 revealed that increased rates of head saccades resembled the spontaneous response evoked by a novel stimulus more closely than it resembled the response evoked by a perched raptor, suggesting that distress calls inculcated a visual exploratory response, rather than an antipredator response. While it is usually thought that the level of acquisition in learners follows a simple relationship with the level of alarm shown by demonstrators, the present results suggest that this relationship may be more complex. Antipredator signals with different functions may have differential effects on learners.

Abstract: Stress in humans has been reported to be associated with a decrease in the salivary immunoglobulin A (s-IgA) levels enabling the possible use of s-IgA to assess stress. Prolonged stress, if reliably assessed in a non-invasive manner, may be used to assess animal welfare. This study analysed groups of dogs undergoing physical and temperamental training and s-IgA levels were measured by rocket immunoelectrophoresis in prospective samples. Behavioural assessment was carried out and cortisol levels in saliva were measured by ELISA. A significant negative correlation (P < 0.007) between the logarithmic cortisol concentrations and s-IgA levels in saliva was recorded. The behavioural assessment of the dogs agreed well with the biochemical markers. It is concluded that IgA levels in saliva may be a useful marker of dog well-being and that stress results in decreased s-IgA levels.

Abstract: Summary The effects of various factors on the inflammatory and stress response in horses during transportation were examined in Experiments 1 and 2, carried out in April and August, respectively. In Experiment 1, three groups (G1-G3) of four Thoroughbreds were used, and in Experiment 2, two groups (G4, G5). G1 animals were loaded into lorries with their heads facing forwards (FF) and given periods of short rest (SR) (30 min for every 4 h driven). G2 horses were loaded facing rearwards (FR) and given SR. G3 horses were FF and given periods of long rest (LR) (2 h rest for every 4 h driven). G4 horses were transported FF with hay suspended in front of them and no cleaning of faeces or urine during rest stops. G5 horses were FF and given pellets instead of hay, and the lorry was cleaned and washed at each rest stop. G4 and G5 horses were rested for 1 h after every 5 h of driving. All groups were driven a distance of 1500 km, and the total journey time was 37 h for G1 and G2, 49 h for G3, and 40 h for G4 and G5. In Experiment 1, indicators of inflammatory and stress responses tended to be highest in G1, intermediate in G2 and lowest in G3. In Experiment 2 they tended to be higher in G4 than in G5. The results suggested that increasing the rest time and cleaning the interior of the vehicle during rest stops reduced transportation stress and respiratory insults, factors that may lead to respiratory disease.