Nina Cracknell

Animals can assign novel odours to a known category

The ability to identify a novel stimulus as a member of a known category allows an organism to respond appropriately towards it. Categorisation is thus a fundamental component of cognition and an essential tool for processing and responding to unknown stimuli. Therefore, one might expect to observe it throughout the animal kingdom and across sensory domains. There is much evidence of visual categorisation in non-human animals, but we currently know little about this process in other modalities. In this experiment, we investigated categorisation in the olfactory domain. Dogs were trained to discriminate between 40 odours; the presence or absence of accelerants formed the categorical rule. Those in the experimental group were rewarded for responding to substrates with accelerants (either burnt or un-burnt) and inhibit responses to the same substrates (either burnt or un-burnt) without accelerants (S+ counterbalanced). The pseudocategory control group was trained on the same stimuli without the categorical rule. The experimental group learned the discrimination and animals were able to generalise to novel stimuli from the same category. None of the control animals were able to learn the discrimination within the maximum number of trials. This study provides the first evidence that non-human animals can learn to categorise non-biologically relevant odour information.

Professionalism, public opinion and placebos

In an age where information is everywhere, there is no shortage of opinion from owners about what we should be doing as clinicians but, as professionals, it is our job to make informed evidence-based decisions and resist popular pressure and media hype. Two excellent examples of why this is so important are given in the current edition. In the first, Talbot et al. [1] highlight the importance of appreciating the power of the placebo. Although no better than placebo, they found that 79% of owners said they would use a supplement again, and in our own work on headshaking [2], we have found that 70% of subjects improved to some degree, regardless of the treatment used, with 30% of owners using a placebo reporting a reduction in the frequency of signs of more than 50%. When faced with a condition for which efficient diagnoses and reliable treatments have yet to be established, the knowledge void can be expected to be filled by individuals and organisations offering potential solutions, which may even seem effective, but which are not specifically useful. In practice, it is important to recognise that there are at least 4 general reasons why we might observe a change in a patient’s condition following intervention: nonspecific effects such as the placebo effect, natural resolution, regression to the mean (the natural drift towards the typical severity of the condition that you would expect to occur if you start with more extreme individuals at the outset, as might occur when trying to recruit subjects for a clinical trial), and the specific effects of treatment. Evidence of efficacy based on personal experience (whether that be the client’s or our own) is not sufficient since, as Talbot et al. [1] show, owners are biased observers; where there is hope there is often a similar change in perception even when there is no physical change. It is also very human to look for causal associations in the relationships between events, and while this may be at the root of some of our intellect, it can also undermine proper understanding, in the absence of a scientific approach. In a condition such as headshaking that is associated with seasonal remission in approximately 64% of cases [3], it is inevitable that some animals will recover around the time a new treatment is tried. Those without a scientific perspective will then be tempted to see a causal link between intervention and recovery, when, in reality, there is none. This risk is greater when owners keep trying new options as they get frustrated with a lack of progress to date. And there is no shortage of new options, with perhaps celebrity endorsement or testimonials appearing regularly on the Internet and especially special interest discussion forums to tempt them further. Such claims are far from harmless, and do more than simply waste owners’ money. In some cases, the ingredients have the potential to be positively harmful, but even if they are harmless, they may delay the implementation of treatments that genuinely improve the well-being of the patient. Similar problems can beset an unscientific approach to the wealth of opinion on equine management and training. Electronic discussion boards and magazines are filled with details about the latest training methods and why one individual’s approach is better than another. Personal opinions abound and may be reinforced by celebrity endorsement to persuade the impressionable. In some cases, scientific principles may be misrepresented in order to make a claim that one particular method is more ‘humane’ than another. A little knowledge can be a dangerous thing as it leads to the oversimplification of complex issues. Christensen [4] shows that forced exposure using controlled negative reinforcement in the form of pressure and release increases the rate of acceptance of a novel stimulus in an open field setting, compared with a simple habituation procedure in which no aversive is used. Although the procedure increases arousal, if well managed, as in her case, then it does not appear to compromise welfare. Like Talbot et al. [1], this work illustrates the danger of drawing conclusions from popular perceptions of what is good for a horse, and the importance of an objective scientific approach. There has been growing interest in a more scientific approach to horse management and training with the creation of organisations such as the International Society for Equitation Science (http://www.equitationscience.com), and this has quite rightly led to the questioning of some traditional practices. This is partly fuelled by evidence of an apparent lack of understanding about learning theory by those involved in training [5]. However, this questioning has sometimes gone beyond the level and style of scientific enquiry and become more like a fanatical rejection of certain methods. This has led some to propose alternatives, that do not involve the deliberate application of aversives, and claims that these alternatives are more humane as a result. However, the popular understanding of the underpinning theory may be equally confused or deliberately misrepresented by these practitioners. For example, anyone who claims to use rewards only and never punishment in their training, fails to acknowledge that the omission of a reward is a form of punishment (negative punishment), and so either does not attend to the impact of this in their work or is misrepresenting what they do. Science is focused on uncovering the truth as best we can, and if we genuinely care for horses, we should not be afraid of what it tells us. However, we do need to beware of the pressure that comes from popular opinion if we are to maintain professional standards. In this age of ubiquitous electronic information, it is perhaps more important than ever, that we make sure we educate owners about the benefits that come from a professional scientific approach. In particular, it teaches us to distinguish between what we know and what we believe. Professional opinion is not simply the personal opinion of someone educated to a professional standard, but rather it is an opinion reached in a professional way, and that means, when it comes to evaluating treatments, having a thorough understanding of the placebo effect, especially given a common false belief that you cannot have a placebo effect with a nonhuman animal, as it does not know it is being treated. The placebo effect refers to the positive, but nonspecific effects of being treated, which are not specifically attributable to the treatment being administered [6]. Two mechanisms, which are commonly ascribed to the placebo effect in man, are expectancy and conditioning, and these also provide plausible explanations for apparent placebo effects in the reported treatment of animals. Expectancy relates to the client’s or trial participant’s preconceptions and expectations following a veterinary consultation or interaction with a researcher. Expectancy effects can be induced by many factors and can lead to the owner perceiving a treatment effect, even if none exists. In human medicine it has been shown that the attentiveness of the doctor [7], the size and colour of pills [8,9], the cost of the treatment [10] and the use of ‘different’ forms of treatment such as injections [11] can all enhance the expectancy effect. Thus alternative therapies may experience high rates of placebo effect due to the generally longer and more personal interaction that occurs between owner and therapist, and the potential for the characteristics of the therapies, such as novelty or cost, to provoke more expectancy of effect in patients. It seems reasonable to suppose that a similar expectancy effect exists in the treatment of animals. Conditioning may also play a role in the owner’s expectation of effect. For example, if the owner has a history of their animal getting better following a visit from the vet they may expect that this will happen on subsequent visits irrespective of the treatment given. Both expectancy and conditioning may have an indirect effect on the animal through the owner, especially in the case of a management related problem. An owner’s optimism that there will be a change may lead to a change in their behaviour and/or body language that in turn could cause a change in the horse’s behaviour [12], or could lead to a change in the owner’s interpretation of their horse’s behaviour. So, for example certain types of shaking of the head may now be dismissed as being more incidental. As a result of these expectancy and conditioning effects, the placebo effect will typically play a greater role in clinical trials where the outcome measures are assessed by owner report. bs_bs_banner

A Systematic Review of the Reliability and Validity of Behavioural Tests Used to Assess Behavioural Characteristics Important in Working Dogs

Background Working dogs are selected based on predictions from tests that they will be able to perform specific tasks in often challenging environments. However, withdrawal from service in working dogs is still a big problem, bringing into question the reliability of the selection tests used to make these predictions. Methods A systematic review was undertaken aimed at bringing together available information on the reliability and predictive validity of the assessment of behavioural characteristics used with working dogs to establish the quality of selection tests currently available for use to predict success in working dogs. Results The search procedures resulted in 16 papers meeting the criteria for inclusion. A large range of behaviour tests and parameters were used in the identified papers, and so behaviour tests and their underpinning constructs were grouped on the basis of their relationship with positive core affect (willingness to work, human-directed social behaviour, object-directed play tendencies) and negative core affect (human-directed aggression, approach withdrawal tendencies, sensitivity to aversives). We then examined the papers for reports of inter-rater reliability, within-session intra-rater reliability, test-retest validity and predictive validity. Conclusions The review revealed a widespread lack of information relating to the reliability and validity of measures to assess behaviour and inconsistencies in terminologies, study parameters and indices of success. There is a need to standardise the reporting of these aspects of behavioural tests in order to improve the knowledge base of what characteristics are predictive of optimal performance in working dog roles, improving selection processes and reducing working dog redundancy. We suggest the use of a framework based on explaining the direct or indirect relationship of the test with core affect.

Treatment for fear of fireworks in dogs

SIR, — We are currently undertaking an extensive series of studies into the efficacy of homeopathic remedies. Having already completed a placebo-controlled study in the efficacy of a homeopathic treatment for firework fear in dogs, we will next be undertaking a twin cohort study at the end of this

Management of fear of fireworks in dogs

SIR, – We have been approached by a company to independently coordinate a clinical trial of a homeopathic remedy for the management of fear of fireworks in dogs. However, we should emphasise we are not applying for the recognition of the study by the James Randi Educational Foundation ( VR ,