The Social Behaviour of Neutered Male Dogs Compared to Intact Dogs (Canis Lupus Familiaris): Video Analyses, Questionnaires and Case Studies

Introduction: Gonadectomy is a regularly performed procedure in domestic dogs. Apart from preventing reproduction, neutering is also conducted for reasons of health and to change or remove undesirable behaviour. From the ethological perspective, castration may have a negative impact on the social behaviour of male dogs. Objectives: The question to be answered is whether there are differences in certain behaviours between neutered and intact male dogs and to gain further insight into the effects of neutering on a male dog's behaviour by comparing the social behaviour of neutered and intact animals in an observational part as well as by evaluating questionnaires submitted by dog owners. Methods: Using video recordings from Germany and Switzerland of six groups of dogs, consisting of 18 intact and 16 neutered males in total, the social behaviour of the dogs was analyzed. Specific behaviours were compared between the castrated and intact males and statistically analyzed. Furthermore, 29 questionnaires based on the studies conducted by Turcsn et al on 104 dogs and their dog owners have been incorporated into this study. Additionally, 54 case studies from our consultancy were evaluated. Results: Significant differences were found in patterns of behaviour such as smelling and licking the genital area, chin rest, tooth chatter and molesting other dogs (Mann-Whitney-U-Test, U=382.000, p=0.001, when analysed in frequencies; Randomization test for 'molesting', F=13.044; p=0.001, when analysed for its duration ). Also, the non-castrated males show more behaviour indicating high status. The results of the questionnaires indicate a trend that neutered males react emotionally more unstable in stressful situations and the case studies show a tendency for aggressive behaviour and fear to be more frequent in castrated dogs. Conclusion: Our results support the assumption that castration may have a negative influence on the behaviour of male dogs. Neutered dogs may gain attractiveness for intact dogs which can lead to a high stress factor for the castrates. Accordingly, dog owners should be aware of the consequences for the dog.