Do predator attacks on productive species and the respective economic losses influence the psychological distress of farmers in Uruguay? A cross-sectional study.

INTRODUCTION: In Uruguay, productive animals are attacked by various predators, causing injuries and financial losses, leading to great concern for farmers. The objective of this study was to determine, using a cross-sectional study, if predator attacks on productive animals during the year 2021 influenced the psychological distress of farmers. METHODS: Four hundred and forty-two farmers from around the country were surveyed with questions according to the Kessler Psychological Distress Scale (dependent variable), and predator attacks received in 2021 (independent variable). RESULTS: Of the total number of farmers surveyed, approximately 49% (216/442) had animals that had been attacked by predators. Farmers whose productive species were attacked in 2021 had higher levels of psychological distress than those whose animals were not attacked (p<0.01). Additionally, farmers who reported the highest levels of psychological distress had more deaths of productive species (and more financial losses) from predator attacks in 2021 than those who did not. CONCLUSION: The losses of productive species and the financial costs negatively influenced the psychological distress of farmers. This information highlights the need to generate public policies about farmers wellbeing that help them in these situations.

Identification of Candidate Genes and Pathways Linked to the Temperament Trait in Sheep.

Temperament can be defined as the emotional variability among animals of the same species in response to the same stimulus, grouping animals by their reactivity as nervous, intermediate, or calm. Our goal was to identify genomic regions with the temperament phenotype measured by the Isolation Box Test (IBT) by single-step genome-wide association studies (ssGWAS). The database consisted of 4317 animals with temperament records, and 1697 genotyped animals with 38,268 effective Single Nucleotide Polymorphism (SNP) after quality control. We identified three genomic regions that explained the greatest percentage of the genetic variance, resulting in 25 SNP associated with candidate genes on chromosomes 6, 10, and 21. A total of nine candidate genes are reported for the temperament trait, which is: PYGM, SYVN1, CAPN1, FADS1, SYT7, GRID2, GPRIN3, EEF1A1 and FRY, linked to the energetic activity of the organism, synaptic transmission, meat tenderness, and calcium associated activities. This is the first study to identify these genetic variants associated with temperament in sheep, which could be used as molecular markers in future behavioral research.

Sexual behaviour of young rams is improved and less stressful after intranasal administration of oxytocin.

The aim of this study was to determine if intranasal administration of oxytocin modifies sexual behaviour and the stress response in young rams during sexual tests with ewes in oestrus. Ten rams were used in a cross-over design. At Day 0, the control group (CG, n = 5) received isotonic saline spray intranasally, and the treated group (OTG, n = 5) received oxytocin (24 IU) intranasally, 40 min before the sexual test. At Day 15, the groups were reversed. In each sexual test (20 min) with an oestrous-induced ewe, the sexual behaviour of the young rams was recorded. Serum cortisol concentrations were determined before and after the test. Less flehmen was observed in the OTG, but mounts with ejaculation were increased. The OTG presented lower serum cortisol concentration than the CG. In conclusion, intranasal administration of oxytocin modified the sexual behaviour of rams, evidenced by a decrease in flehmen behaviour and an increase in mounts with ejaculation, making sexual activity more efficacious. In addition, the treatment decreased the stress response of the rams in the sexual tests. Therefore, intranasal administration of oxytocin could be used to increase sexual activity in rams, and with less stress, providing better welfare conditions.

Clinical signs associated with prostatic disorders in canines: Retrospective study in Uruguay (2011-2019).

Background: Prostate disease represents about 0.7% of diseases in canines. The main diagnosed pathology is benign prostatic hyperplasia (BPH). However, the reports that study the association of a certain clinical sign with a specific prostate disease are scarce. Aim: The main objective of this study was to evaluate the clinical relevance of the most commonly observed clinical signs associated with the different prostatic disorders in canines admitted to the hospital of the Facultad de Veterinaria-Universidad de la República between 2011 and 2019. Methods: This retrospective study included 7,729 male canines treated at the hospital de la Facultad de Veterinaria-Universidad de la República (Montevideo, Uruguay) between 2011 and 2019. 289 canines with a presumptive/definitive diagnosis of prostate diseases were selected, recording the presence/absence of associated clinical signs. Results were reported in terms of odds ratios (ORs) using logistic regression (p < 0.05). Results: The five most frequently reported clinical signs were tenesmus (34%), anorexia (32%), lethargy (27%), prostatomegaly or pain during rectal examination (25%), and abdominal pain from palpation (22%). Diarrhea (3.39 vs. 0.33 OR), anorexia (2.07 vs. 0.39 OR), weight loss (2.27 vs. 0.27 OR), hematuria (3.25 vs. 0.44 OR), and urinary incontinence (2.96 vs. 0.33 OR) indicated a highest predictive value (p < 0.05) with prostatitis versus BPH, respectively. Being weight loss, the clinical sign is more frequently associated with neoplasia (20.2 OR, p = 0.002). Conclusion: This study shows that there are clinical signs with a higher degree of association for certain canine prostatic disorders than others.

In Vivo Ultrafast Doppler Imaging Combined with Confocal Microscopy and Behavioral Approaches to Gain Insight into the Central Expression of Peripheral Neuropathy in Trembler-J Mice.

The main human hereditary peripheral neuropathy (Charcot-Marie-Tooth, CMT), manifests in progressive sensory and motor deficits. Mutations in the compact myelin protein gene pmp22 cause more than 50% of all CMTs. CMT1E is a subtype of CMT1 myelinopathy carrying micro-mutations in pmp22. The Trembler-J mice have a spontaneous mutation in pmp22 identical to that present in CMT1E human patients. PMP22 is mainly (but not exclusively) expressed in Schwann cells. Some studies have found the presence of pmp22 together with some anomalies in the CNS of CMT patients. Recently, we identified the presence of higher hippocampal pmp22 expression and elevated levels of anxious behavior in TrJ/+ compared to those observed in wt. In the present paper, we delve deeper into the central expression of the neuropathy modeled in Trembler-J analyzing in vivo the cerebrovascular component by Ultrafast Doppler, exploring the vascular structure by scanning laser confocal microscopy, and analyzing the behavioral profile by anxiety and motor difficulty tests. We have found that TrJ/+ hippocampi have increased blood flow and a higher vessel volume compared with the wild type. Together with this, we found an anxiety-like profile in TrJ/+ and the motor difficulties described earlier. We demonstrate that there are specific cerebrovascular hemodynamics associated with a vascular structure and anxious behavior associated with the TrJ/+ clinical phenotype, a model of the human CMT1E disease.

Epidemiology of dog bites to people in Uruguay (2010-2020).

BACKGROUND: Dog bites to people are a serious public health problem. Limited information exists at the country level in Latin America. The COVID-19 pandemic changed people's lifestyles and their relationship with pets, and this could potentially affect the incidence of dog bites injuries. OBJECTIVE: The main objectives of our study were to determine the prevalence of dog-bite injuries in Uruguay from 2010 to 2020 and to compare the prevalence in 2020 to that of pre-pandemic years. METHODS: Cross-sectional study. Dog-bite notifications for the 2010 and 2020 period were analysed using data from the Uruguayan Ministry of Public Health. RESULTS: The annual dog-bite injury rate for the 2010-2020 period was 87.51 per 100,000 people. The frequency of bites varied with the victims' sex, with males accounting for 51.8% of the bites (p < 0.0001), and with age, with a higher frequency of bites in the ≤14 years old age group (p < 0.01). The frequency of dog bites was also higher in spring and summer than in autumn (p < 0.0001). There was no statistical difference in the frequency of dog-bite injuries when comparing 2020 with the pre-COVID-19 pandemic years. CONCLUSIONS: In Uruguay, the frequency of dog-bite injuries varied with season and with the age and sex of the victim. In the first year of the COVID-19 pandemic, the number of people bitten by dogs was no different than that of previous years. This is the first study in Latin America to report national rather than regional data and to include all age groups.

The environment matters: season and female contact affect the behavior of captive Addax nasomaculatus male antelope.

The addax antelope (Addax nasomaculatus) is a species under serious threat of extinction, as it is more abundant in captivity than in the wild. However, little is known about its basic biology. The aims of this study were to determine how locomotor, feeding, aggressive, marking, and sexual behavior of male addax allocated in all-male groups vary with season and with female contact (i.e., biostimulation). The study was conducted in captive conditions, in two groups of adult males: one with no-physical contact with females, aside from visual and olfactory interactions (CF group, n = 4), and another group completely isolated from females (IF group, n = 4). The frequency of behaviors was recorded during the daytime, 4 days per season (total time of observation = 256 h). Lying, standing, walking, aggressive, marking, grazing, and ruminating behaviors as well as water and supplement consumptions varied with season (all p < 0.05). The lying, walking, marking, grazing, and ruminating behaviors were more frequently observed for CF than IF males (all p < 0.05). Also, all behaviors, except for marking, varied with the interaction between the group and seasons (all p < 0.05). Sexual behavior was extremely scarce, so it was not possible to analyze how it varied with seasons and the group. The present study suggests that management program and housing conditions, especially in ex situ breeding plans, should consider the influence of the season and the sociosexual context on the behavior of addax males.

Characterization of the Domestic Cat Population of Uruguay: Breeds, Coat Colors, Hair Length, Lifestyle, Sex and Spay/Neuter Status According to Guardian Report.

The objective of this study was to characterize the domestic cat population of Uruguay in relation to breed, coat color, hair length, lifestyle (indoor vs. outdoor), age, sex, and spay/neuter status according to a survey completed by their owners or guardians. An online survey, distributed to residents of Uruguay, was completed in full by 2561 cat guardians. Descriptive statistics and Chi-squared tests were performed. The population of cats with guardians in Uruguay is characterized by the following data: higher frequency of female cats (53%), most of the cats were between two and six years old (49%), most of them were neutered (84%, mainly those older than one year of age), most of them have outdoor access (87%), a very low percentage (6%) are purebred (Siamese being the most frequent: 86%), and within the non-pure breeds, short hair cats were the most frequent (79%). This study, in addition to expanding the information on the characteristics of cats with guardians from other countries and continents, is the first study in Latin America to describe some key demographic aspects such as cat breeds, coat color, hair length, lifestyles, and frequency by age, sex, and spay/neuter status (spayed/neutered or not) at the country level.

Udder Hygiene and Mastitis Indicators in Contrasting Environmental Conditions during Half-Time Confinement in Pasture-Based Dairy Systems.

This study aimed to compare the association between two types of housing, compost barns (CB) vs. outdoor soil-bedded yard (OD), and udder hygiene and mastitis indicators in Holstein dairy cows calving in autumn (n = 31) and spring (n = 27). After calving, cows were transferred to a pasture-based system with half-time confinement in one of two treatments: CB or OD. The udder hygiene score (UHS) was evaluated monthly and on days after rainfall over the entire lactation period. Individual somatic cell count (SCC) was determined throughout lactation, and the prevalence of intramammary infection (IMI) was estimated. Cows confined in OD presented higher UHS compared to cows in CB (p < 0.05) in both calving seasons. After rains, autumn-calving cows in OD were dirtier than on days without previous rain (OR = 1.85, CI 95%: 1.1-3.1; p < 0.02). However, no differences in IMI and clinical mastitis were found between OD and CB cows in either calving season.

Characterization of Raid Hipico Uruguayo Competencies by Ride Type: Causes of Death and Risk Factors.

RHU is the oldest endurance sport in Uruguay. However, despite 80 years of racing, there are no studies to characterize this type of competition, explore rates and causes of death, and identify the associated risk factors. The aim was to characterize the Raid Hipico Uruguayo (RHU) competencies according to the distance (short (SR, 60 km) vs. long (LR, 80-115 km)), the causes of deaths, and the associated risk factors. The study population comprised horses (n = 16,856) that participated in RHU rides from 2007 to 2018. LR were more frequent than SR (p < 0.001). The average speed of winners was higher in SR (32.12 km/h) than in LR (28.14 km/h) (p < 0.001). There were 99 fatalities (5.9 per 1000 starts). SR had greater frequency of high comfort index (CI = Temp [°F] + Humidity [%]) than LR, and LR had greater frequency of low CI than SR (p < 0.001). The percentage of inexperienced horses and those who completed the ride was greater in SR than in LR (p < 0.001). In both types of rides, more horses died during than after the ride, and inexperienced horses were more likely to suffer fatalities than horses with prior experience in the sport (p < 0.05). SR were associated with increased risk of sudden death, while LR were associated with increased risk of death due to metabolic alterations. The high fatality index shown in this work warrants urgent investigation in this sport to minimize mortality associated with RHU-specific diseases.

Different Conditions during Confinement in Pasture-Based Systems and Feeding Systems Affect the Fatty Acid Profile in the Milk and Cheese of Holstein Dairy Cows.

The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how these are affected by different conditions during confinement in a mixed system (MS:grazing + total mixed ration:TMR) is not known. The aim of this study was to compare the FAs of the milk and cheese from MS in a compost-bedded pack barns (CB-GRZ) versus an outdoor soil-bedded pen (OD-GRZ) during confinement, and with a confinement system (100%TMR) in a compost-bedded pack barns (CB-TMR). Individual milk samples (n = 12 cows/group), cheese, and pooled milk (MilkP) samples were collected. The saturated FA percentages in the milk and the omega 6/omega 3 ratio in the MilkP and cheese were greater for the CB-TMR (p < 0.0001), while the unsaturated and monounsaturated FA percentages in the milk were lower for the CB-TMR than the MS (p < 0.001). The milk n-3, C18:3, and conjugated linoleic acid percentages were lower for the CB-TMR than the MS (p < 0.001). The milk n-3 and C18:3 were higher for the CB-GRZ than the OD-GRZ (p < 0.01), but no differences were observed between the MS in the MilkP and cheese. In conclusion, CB-GRZ cows during confinement produced better quality milk compared to OD-GRZ cows. However, the FA profiles of the milk, MilkP, and cheese were affected to a greater extent by the feeding management than by the conditions during confinement.

Dairy Cows' Temperament and Milking Performance during the Adaptation to an Automatic Milking System.

Adaptative responses of cows to an automatic milking system (AMS) could depend on their temperament, i.e., cows with certain temperament profiles could be able to cope more successfully with the AMS. The relationships between dairy cows' temperament, behaviour, and productive parameters during the changeover from a conventional milking system (CMS) to an AMS were investigated. Thirty-three multiparous cows were classified as 'calm' or 'reactive' based on each of the temperament tests conducted: race time, flight speed (FS), and flight distance, at 5, 25, and 45 days in milk at CMS, then the cows were moved from the CMS to the AMS. During the first five milkings in AMS, the number of steps and kicks during each milking were recorded. The daily milk yield was automatically recorded. The number of steps did not vary by temperament classification, but the number of kicks per milking was greater for calm (0.45 ± 0.14) than for reactive cows (0.05 ± 0.03) when they were classified by FS (p < 0.01). During the first seven days in the AMS, reactive cows for the FS test produced more milk than calm cows (36.5 ± 1.8 vs. 33.2 ± 1.6 L/day; p = 0.05). In conclusion, behavioural and productive parameters were influenced by cows´ temperament during the milking system changeover since the calm cows kicked more and produced less than the reactive ones.

CaMKIV/CREB/BDNF signaling pathway expression in prefrontal cortex, amygdala, hippocampus and hypothalamus in streptozotocin-induced diabetic mice with anxious-like behavior.

Individuals with diabetes mellitus (DM) tend to manifest anxiety and depression, which could be related to changes in the expression of calcium/calmodulin-dependent protein kinase IV (CaMKIV), transcription factor cyclic AMP-responsive element binding protein (CREB), phosphorylated CREB (pCREB) and brain-derived neurotrophic factor (BDNF) in different brain regions. The objective of this study was to determine whether mice with type 1 diabetes (T1DM) induced with streptozotocin show a profile of anxious-type behaviors and alterations in the expression/activity of CaMKIV, CREB, pCREB and BDNF in different regions of the brain (prefrontal cortex, amygdala, hippocampus and hypothalamus) in comparison to non-diabetic mice (NDB). Mice with 3 months of chronic DM showed an anxious-like behavioral profile in two anxiety tests (Open Field and Elevated Plus Maze), when compared to NDB. There were significant differences in the expression of cell signaling proteins: diabetic mice had a lower expression of CaMKIV in the hippocampus, a greater expression of CREB in the amygdala and hypothalamus, as well as a lower pCREB/CREB in hypothalamus than NDB mice (P < 0.05). This is the first study evaluating the expression of CaMKIV in the brain of animals with DM, who presented lower expression of this protein in the hippocampus. In addition, it is the first time that CREB was evaluated in amygdala and hypothalamus of animals with DM, who presented a higher expression. Further research is necessary to determine the possible link between expression of CaMKIV and CREB, and the behavioral profile of anxiety in diabetic animals.

Intensity distribution segmentation in ultrafast Doppler combined with scanning laser confocal microscopy for assessing vascular changes associated with ageing in murine hippocampi.

The hippocampus plays an important role in learning and memory, requiring high-neuronal oxygenation. Understanding the relationship between blood flow and vascular structure-and how it changes with ageing-is physiologically and anatomically relevant. Ultrafast Doppler ([Formula: see text]Doppler) and scanning laser confocal microscopy (SLCM) are powerful imaging modalities that can measure in vivo cerebral blood volume (CBV) and post mortem vascular structure, respectively. Here, we apply both imaging modalities to a cross-sectional and longitudinal study of hippocampi vasculature in wild-type mice brains. We introduce a segmentation of CBV distribution obtained from [Formula: see text]Doppler and show that this mice-independent and mesoscopic measurement is correlated with vessel volume fraction (VVF) distribution obtained from SLCM-e.g., high CBV relates to specific vessel locations with large VVF. Moreover, we find significant changes in CBV distribution and vasculature due to ageing (5 vs. 21 month-old mice), highlighting the sensitivity of our approach. Overall, we are able to associate CBV with vascular structure-and track its longitudinal changes-at the artery-vein, venules, arteriole, and capillary levels. We believe that this combined approach can be a powerful tool for studying other acute (e.g., brain injuries), progressive (e.g., neurodegeneration) or induced pathological changes.

Post-castration prostatic involution: A morphometric and endocrine study of healthy canines and those with benign prostatic hyperplasia.

The objective of this study was to evaluate the effect of castration on dimensions of the prostate by B-mode ultrasound for 90 days, as well as to evaluate changes in serum concentrations of testosterone and oestradiol in clinically healthy canines and those with benign prostatic hyperplasia (BPH). Three groups of animals were used: healthy canines castrated on day 0 (HCC, n = 8), canines with a diagnosis of benign prostatic hyperplasia (BPHC, n = 9) castrated on day 0 and healthy uncastrated canines (IHCC, n = 10). Prostate size was obtained by B-mode ultrasound, while blood samples were collected (days 0, 7, 14, 28, 60 and 90 post-castration) to determine the serum testosterone and oestradiol concentration. Castration did not affect serum oestradiol concentrations. Castration led to a decrease in serum testosterone (reaching values <20 ng/dl in the first week, p < .05), causing a gradual decrease in dimensions of prostate parameters relative to body weight (p < .05). Canines with BPHC had similar prostate dimensions as the IHCC group 2 weeks post-castration. In relation to the prostate's relative parameters, the decrease with time was greater in canines with BPHC than those in the HCC group. When evaluating parameters as a percentage of relative change, the decrease with time was similar in both castrated groups, except for relative length percentage, which presented a more pronounced decline in BPHC canines than HCC canines. In conclusion, castration is an effective, fast and long-lasting treatment for canine patients with BPH, as it causes a rapid decrease in blood testosterone concentrations and a decrease in glandular volume, but does not affect serum oestradiol concentrations. This study did not determine the mechanisms of action, but allowed us to observe (based on morphometric variables) that characteristics of prostate involution after castration differed between canines with BPH and healthy canines.

Central Alteration in Peripheral Neuropathy of Trembler-J Mice: Hippocampal pmp22 Expression and Behavioral Profile in Anxiety Tests.

Charcot-Marie-Tooth (CMT) type 1 disease is the most common human hereditary demyelinating neuropathy. Mutations in pmp22 cause about 70% of all CMT1. Trembler-J (TrJ/+) mice are an animal model of CMT1E, having the same spontaneous pmp22 mutation that is found in humans. We compared the behavior profile of TrJ/+ and +/+ (wild-type) in open-field and elevated-plus-maze anxiety tests. In these tests, TrJ/+ showed an exclusive head shake movement, a lower frequency of rearing, but a greater frequency of grooming. In elevated-plus-maze, TrJ/+ defecate more frequently, performed fewer total entries, and have fewer entries to closed arms. These hippocampus-associated behaviors in TrJ/+ are consistent with increased anxiety levels. The expression of pmp22 and soluble PMP22 were evaluated in E17-hippocampal neurons and adult hippocampus by in situ hybridization and successive immunohistochemistry. Likewise, the expression of pmp22 was confirmed by RT-qPCR in the entire isolated hippocampi of both genotypes. Moreover, the presence of aggregated PMP22 was evidenced in unmasked granular hippocampal adult neurons and shows genotypic differences. We showed for the first time a behavior profile trait associated with anxiety and a differential expression of pmp22/PMP22 in hippocampal neurons of TrJ/+ and +/+ mice, demonstrating the involvement at the central level in an animal model of peripheral neuropathy (CMT1E).

Intranasal oxytocin affects the stress response to social isolation in sheep.

Oxytocin (OT) is a neuropeptide hormone that modulates several social behaviors and can affect the anxiety and stress response. The aim of this study was to determine if administration of intranasal OT affects the stress response to social isolation in sheep. Twenty adult Merino ewes were assigned to two groups; 1) Control group (CG, n = 10), which received an intranasal administration of isotonic saline and 2) Oxytocin-treated group (OTG, n = 10), which received an intranasal administration of OT (24 IU) 40 min before the animals were placed in the social isolation test. During the social isolation test (10 min), the behavior of the sheep was recorded, and blood samples were obtained before and after the test for the determination of cortisol, glucose and serum proteins, and heart rate and surface temperature were recorded. The OTG ewes had a higher cortisol concentration (P = 0.04) after social isolation, tended to vocalize more (P = 0.06) during isolation, and tended to have lower globulin concentrations (P = 0.10) than the CG ewes. Contrary to what we expected, the administration of intranasal OT increased the stress response to social isolation in ewes, which was evidenced by endocrine (greater increase in cortisol concentration), physiological (a tendency to present lower concentration of globulins in blood) and behavioral (a tendency to vocalize more) indicators. This study suggests that the administration of intranasal OT increased the stress response to isolation possibly by strengthening the social bond among ewes.

Growth of foetal bones and metabolic profile during gestation in primiparous ewes and multiparous ewes.

Primiparous ewes and multiparous ewes show physiological differences during pregnancy, which can have an impact on the development of their offspring. The objective of this study was to compare the changes in the metabolic profile and in the size of some foetal bones throughout gestation between primiparous and multiparous ewes. Twelve primiparous (PM) ewes and 14 multiparous (MT) ewes were used. According to the dates of lambing, two groups of ewes were formed: Group 1 (G1, n = 6 PM and n = 7 MT) and Group 2 (G2, n = 6 PM and n = 7 MT). The body weight, body condition score, metabolic and foetal morphometric parameters were determined from before conception until the end of gestation. After lambing, the body weight and survival rate during the first 72 hr of life of lambs, as well as the maternal behaviour score were recorded. The PM ewes were lighter (p < .01) and had a greater mobilization of body reserves during gestation, mainly evidenced by a greater serum concentration of NEFAs and lower serum concentration of total proteins (p < .05) compared with the MT ewes. The parity did not affect the foetal morphometric variables. The lambs of MT ewes were heavier at parturition (p = .002) and tended to have a greater survival rate than those lambs of PM ewes (p = .09). In conclusion, PM ewes and MT ewes differ in their metabolic profile throughout the gestation. However, in the present study, we did not find parity differences in the dimensions of foetal bones during growth in gestation.

Do dogs rescue their owners from a stressful situation? A behavioral and physiological assessment.

Rescue behavior is considered a type of pro-social response, defined as a voluntary action directed to benefit another individual who is in a stressful or dangerous situation. In two experiments, we investigated whether dogs would rescue their owners when the person was trapped inside a wooden box and emitted clear signs of stress. The performance of these dogs was compared against that of a control group in which the owners remained calm while trapped. In addition, to assess if training modulated this behavior, we tested a group of dogs from the military trained in search and rescue tasks (Experiment 1). Results showed that dogs opened the box more frequently when the owner pretended to be stressed than when calm. Training shortened latencies to open the door but not the frequency of the behavior. In Experiment 2, we investigated if emotional contagion could be a possible mechanism underlying dogs' rescue responses by measuring dogs' behavior, heart rate, and saliva cortisol level in the stressed and calm conditions, and also controlled for obedience by having the calm owners call their pets while trapped. We replicated the findings of Experiment 1 as more dogs opened the door in the stressed owner condition than in the calm condition. In addition, we observed an increase in heart rate across trials in the stressed condition and a decrease across trials in the calm condition, but no differences in cortisol levels or stress-related behaviors between conditions. In brief, we found evidence that approximately half of the dogs without previous training showed spontaneous rescue behaviors directed to their owners. Neither was this behavior motivated by obedience nor by the motivation to re-establish social contact with the owner. We conclude that emotional contagion is a plausible mechanism underlying dogs' rescue behavior in the present protocol.