Objective: In recent years, the use of zebrafish (Danio rerio) as laboratory models has significantly increased. Ensuring their welfare is crucial, with the cognitive bias test emerging as a valuable tool to assess their emotional state. This systematic review examines the application of the cognitive bias test in zebrafish research. Data: The review adhered to PRISMA guidelines. Sources: A systematic search was conducted in scientific databases, including PubMed and Scopus, yielding 30 articles. Additionally, one abstract identified through bibliographic screening of selected papers was included. Study Selection: Six studies were selected for analysis, and their quality was assessed using SYRCLE’s risk-of-bias tool. Results: Three experimental models were employed to conduct the cognitive bias test in zebrafish, focusing on the relationship between their affective state and environmental conditions, cognitive abilities, and life-history strategies but none of the studies adequately reported the techniques employed to reduce bias. Discussion: The cognitive bias test proved effective in assessing the emotional state of zebrafish; however, methodological biases may have influenced the results. Conclusion: The cognitive bias test offers valuable insights into how emotional states affect cognitive abilities, responses to environmental changes (e.g., physical enrichment), and stress responses. Further research addressing methodological limitations is necessary to validate these findings and improve data reproducibility.

The gut microbiota plays a basic role in maintaining the psychophysical health and well-being of horses. Understanding the complex interactions among microbial communities in relation to age, management, and health is a topic of growing interest. The equine microbiota, given its complexity, is subject to variations caused by internal or external stressors that can lead to metabolic problems and pathologies, i.e., obesity and laminitis. The aim of this study was to characterize the fecal microbiota of 12 purebred Arabian horses and to compare the microbial communities in two distinct management systems (Group 1 = box 22 h/day + paddock 2 h/day and Group 2 = paddock 24 h). Fecal samples were analyzed using high-throughput sequencing of 16S rRNA V3-V4 amplicons. The microbiota was predominantly composed of Firmicutes (32–53%) and Bacteroidetes (32–47.8%), with Ruminococcaceae emerging as the most prevalent bacterial family (10.9–24%). Comparisons of alpha and beta diversity revealed no statistically significant differences between the groups based on different management systems. This preliminary characterization contributes valuable data for understanding the equine fecal microbiota and lays the groundwork for future studies on the relationship among intestinal microbiota and equine health, performance, and management strategies.

Animal-assisted services (AAS) have been shown in multiple studies to improve a range of human psychological and physical health benefits. The aim of this pilot study is to investigate simultaneously two psycho-physiological indicators of the valence of interactions in the context of dog-assisted activities in children diagnosed with autism spectrum disorder. Ten children and four dogs experienced in AAS were involved, lasting 90 days, in weekly one-hour sessions. Before and after each session, saliva was taken in both dogs and children for determination of salivary oxytocin and cortisol levels. In addition, at the end of the program, a questionnaire was administered to both parents and dog handlers to assess the impact of AAS in children and dogs. Our results revealed no statistically significant change in cortisol and oxytocin levels in dogs enrolled throughout the sessions, while an increasing trend was noted for salivary oxytocin in 50% of the dogs and for salivary cortisol in all dogs at the end of the AAS, when compared to the pre-AAS. Salivary cortisol measurement in children with an autistic neurotype highlighted a statistically significant increase at the end of the AAS when compared to the pre-AAS, but this was not observed for oxytocin level evaluations. Regarding the perception of the children’s parents about the effects of the program, our data reported an improvement in sociability of the children in 100 percent of the cases. Furthermore, dog handlers reported an absence of signs of stress in their dogs during the sessions. Although the perceived effectiveness and quality of AAS has been demonstrated in the literature, the need to carefully select the dogs involved, considering their skills and needs, is critical to ensure their well-being in various therapeutic settings.

Shelter environments can be inherently stressful for dogs, a highly social species that forms strong attachment bond with humans. This study evaluated stress responses in 26 shelter dogs during routine veterinary examinations, analyzing behavioral scores alongside physiological and hormonal parameters, including heart rate, body temperature, cortisol (CRT), oxytocin (OXT), serotonin (5-HT), tryptophan (TRP), and interleukin-6 (IL-6). A significant negative correlation was observed between OXT and CRT (ρ = –0.540, p = 0.007), particularly in dogs exhibiting relaxed behavior. OXT was also negatively correlated with body temperature (ρ = –0.435, p = 0.034), supporting its potential role in modulating stress-induced hyperthermia. No significant associations were found between TRP, 5-HT, IL-6, or other physiological measures and behavioral scores. The absence of correlation between TRP and 5-HT may be due to blood–brain barrier regulation, while IL-6′s lack of association suggests further investigation is needed to clarify its role in canine stress responses. These findings highlight OXT’s possible buffering effect on the hypothalamic–pituitary–adrenal axis and suggest that behavioral assessment may offer a more sensitive measure of canine stress than hormonal or physiological parameters alone. Future studies with larger and more diverse samples are needed to confirm and expand upon these results.

Studies on short- and long-term memory and their decline with aging in horses are still limited. This research aimed to assess the learning and short- and long-term memory abilities of adult and senior horses. A total of 21 adult horses (5–15 years) and 23 senior horses (16 years and older) were subjected to a behavioral test (Target Touch Test), which was repeated three times each for the initial test (T1) and again after 10 days (T10). Statistical analysis revealed no significant differences between adult and senior horses in the three tests conducted at T1. However, a significant difference was observed at T10 (χ² = 42.1; p < 0.001). In fact, senior horses took longer to complete the test than adults. A significant difference between males and females, adults and seniors, at T1 and T10 (χ² = 56.3; p < 0.001) was found, but no difference between male and female adult and senior horses in completing the three single tests at T1 and T10 was evidenced. In conclusion, even senior horses are capable of associative learning, maintaining the memory of this learning even after 10 days. However, they show slower recovery times for recalling memorized information compared to animals under 16 years of age.

The impact of enrichment on stress reduction in zebrafish (Danio rerio) exposed to a novel environment was assessed. Four control shoals (CTRL) and five treated shoals (TRT), each with eight fish, were observed; in TRT tanks, a PVC pipe was included (three-way tube, 11.7 × 4 cm) as enrichment for 90 days. Subsequently, fish were moved to a new tank for a shoaling test, and behavior was evaluated over periods of 0′–5′ and 5′–10′. Cortisol dissolved in water was measured before and after the test. No differences were found between the two groups in distance moved, swimming speed, or shoal acceleration. Both groups reduced interindividual distance in the second phase of the test (CTRL: t = 8.977, p ≤ 0.0001; TRT: t = 8.247, p ≤ 0.0001), though TRT fish maintained greater spacing (t = 2.292, p ≤ 0.05). TRT fish spent more time without contact during both phases (first: t = 2.645, p ≤ 0.05; second: t = 3.134, p ≤ 0.01), while CTRL fish reduced this time in the second phase (t = 2.991, p ≤ 0.05). Cortisol rose significantly in CTRL after the test (t = 2.452, p ≤ 0.05) but not in TRT fish. These results suggest that environmental enrichment mitigates stress, as seen by reduced cohesiveness and cortisol in TRT fish.