UK animal welfare, behaviour, training and veterinary organisations1 are warning of the possible dangers of using techniques for training dogs that can cause pain and fear, such as some of those seen used by Cesar Millan, who has announced a UK tour next year. The organisations have joined forces to voice their serious concerns about techniques which pose welfare problems for dogs and significant risk to owners who may copy them. These concerns are shared, and the statement supported, by similar organisations around the world2 and in continental Europe3. Aversive training techniques, which have been seen to be used by Cesar Millan, are based on the principle of applying an unpleasant stimulus to inhibit behaviour. This kind of training technique can include the use of prong collars, electric shock collars, restricting dogs′ air supply using nooses/leads or pinning them to the ground, which can cause pain and distress. The use of such techniques may compromise the welfare of dogs and may worsen the behavioural problems they aim to address, potentially placing owners at considerable risk. A number of scientific studies have found an association between the use of aversive training techniques and the occurrence of undesired behaviours in dogs.