Elephant endotheliotropic herpesvirus (EEHV) haemorrhagic disease is a major threat for juvenile Asian elephants. This study reports a proof-of-concept trial that evaluates the safety and immunogenicity of a vaccine against EEHV.

Behavioural addictions, characterised by compulsive engagement in rewarding activities despite adverse consequences in the long term, are more heterogeneous and less well-understood than substance addictions, and there is a relative lack of translational research. This study investigates “excessive toy motivation” in domestic dogs as a potential parallel to behavioural addictions in humans. Employing a combination of a behavioural test and an owner questionnaire, we examined whether a subset of highly play-motived dogs meet key behavioural addiction criteria, including craving, salience, lack of self-control, and mood modification. Data from 105 highly play-motivated dogs revealed that 33 subjects exhibited behaviours consistent with addictive-like tendencies, including an excessive fixation on toys, reduced responsiveness to alternative stimuli, and persistent efforts to access toys. Owner-reported behaviours not only corroborated these findings but also demonstrated significant associations with behavioural test scores. Our results highlight parallels between excessive toy motivation in dogs and human behavioural addictions, with dogs as the only non-human species so far that appears to develop addictive-like behaviours spontaneously without artificial induction. This exploratory study provides foundational insights and proposes future research directions that have the potential to significantly deepen our understanding of the psychological mechanisms underlying behavioural addictions across species.

To mark World Mental Health Day 2025, we are sharing a selection of Springer Nature journal articles, collections, clinical study registrations and blog posts chosen by our publishers.

Hear the biggest stories from the world of science | 01 October 2025

Stereotypes of age-related gender bias are socially distorted, as evidenced by the age gap in the representations of women and men across various media and algorithms, despite no systematic age differences in the workforce.

A controversial prediction about black holes and the expansion force of the universe could explain a cosmology mystery

Bioplastics derived from biomass show promise as sustainable alternatives to petrochemical plastics, but their adoption is hindered by their inferior mechanical properties and processability. Here, the authors report a deep eutectic solvent treatment process which yields bamboo plastics with high mechanical properties and processability.

Early-career scientists face a tough choice: chase “hot” topics for quick publications or pursue risky, innovative ideas. Limited resources worsen this dilemma. To foster true innovation, funding agencies and institutions must support diversity in research beyond short-term outputs.

Tandem electro-biocatalytic systems present a versatile platform for producing a variety of synthetic products using CO2 as a starting material. Here direct ocean carbon capture is incorporated into an electrolysis scheme to produce formic acid from CO2 dissolved in seawater that is subsequently converted to succinate in a bioreactor.