Conditioned placebo effect in dogs decreases separation related behaviours

The behaviour of overweight dogs shows similarity with personality traits of overweight humans

Excessive food intake and the resulting excess weight gain is a growing problem in human and canine populations. Dogs, due to their shared living environment with humans, may provide a beneficial model to study the causes and consequences of obesity. Here, we make use of two well-established research paradigms (two-way choice paradigm and cognitive bias test), previously applied with dogs, to investigate the role of obesity and obesity-prone breeds for food responsiveness. We found no evidence of breed differences in food responsiveness due to one breed being more prone to obesity than another. Breed differences found in this study, however, can be explained by working dog status, i.e. whether the dog works in cooperation with, or independently from, humans. Our results also confirm that overweight dogs, as opposed to normal weight dogs, tried to maximize food intake from the higher quality food and hesitated to do the task when the food reward was uncertain. These results are very similar to those expected from the parallel models that exist between certain personality traits and being overweight in humans, suggesting that dogs are indeed a promising model for experimentally investigating obesity in humans.

Comparison of veterinary drugs and veterinary homeopathy: part 1

For many years after its invention around 1796, homeopathy was widely used in people and later in animals. Over the intervening period (1796-2016) pharmacology emerged as a science from Materia Medica (medicinal materials) to become the mainstay of veterinary therapeutics. There remains today a much smaller, but significant, use of homeopathy by veterinary surgeons. Homeopathic products are sometimes administered when conventional drug therapies have not succeeded, but are also used as alternatives to scientifically based therapies and licensed products. The principles underlying the veterinary use of drug-based and homeopathic products are polar opposites; this provides the basis for comparison between them. This two-part review compares and contrasts the two treatment forms in respect of history, constituents, methods of preparation, known or postulated mechanisms underlying responses, the legal basis for use and scientific credibility in the 21st century. Part 1 begins with a consideration of why therapeutic products actually work or appear to do so.

Oxytocin induces positive expectations about ambivalent stimuli (cognitive bias) in dogs

Expectancy bias towards positive outcomes is a potential key to subjective well-being, and has been widely investigated in different species. Here we test whether oxytocin, suggested to play a role in human optimism and emotional processing, influences how dogs judge ambivalent situations (in a cognitive bias paradigm). Subjects first learned in a location discrimination task that a bowl either contained food (at the 'positive' location) or was empty (at the 'negative' location). Then, after receiving oxytocin or placebo nasal spray, they were presented with the bowl located halfway between the positive and negative positions in communicative or non-communicative contexts (N=4×16). A Positive Expectancy Score was calculated for each subject using the latency to approach this ambivalent location. Compared to placebo groups, subjects that received oxytocin pretreatment showed a positive expectation bias in both contexts, and this effect was more pronounced in the communicative context. Our study provides the first evidence for the impact of oxytocin on dogs' judgement bias and also shows that the social-communicative nature of the task situation modulates the effect of oxytocin.