This study aimed to explore factors associated with owners reporting problem behaviour in dogs. Owner-completed surveys collected as part of a longitudinal dog health/behaviour study were analysed. Owner-selected training methods were classified into four training categories on a scale from ‘Rewards only’ to ‘Aversive only’ that reflected the proportion of aversive- and rewards-based methods selected. ‘Owner-reported behaviour at 12 months’ (problem reported/ not) was modelled with logistic regression. Predictive variables included: dog/owner demographics; owner-reported behaviour at three timepoints (12/16 weeks, 6 and 9 months), the training category and change in the training category (to a more aversive/less aversive method or maintenance) at three timepoints (12/16 weeks, 9 and 12 months). The model was repeated for a subset of dogs whose owners completed a personality questionnaire (International Personality Item Pool-50). The second model included the predictive variables listed for the first model and owners’ personality scores. Dogs trained with only aversive methods were excluded (n <10). In the first model (X2=312, R2=0.33, p=<0.001, n=1130), owner-reported problem behaviour at 12 months was associated with the increased odds of: owner-reported problem behaviour at 12/16 weeks (OR=1.88, CI%1.38-2.55, p<0.001), 6 (OR= 2.19, CI%1.62-2.97, p<0.001) and 9 months (OR=6.51, CI%4.83-8.83, p<0.001) and changing to a more aversive training category between 9-12 months (compared to changing to a less aversive/ maintenance of the same category; OR=1.66, CI%1.06-2.63, p=0.029). In the second model (X2=178.4, R2=0.35, p=<0.001, n=590) owner-reported problem behaviour at 12 months was associated with increased odds of owner-reported problem behaviour at all previous timepoints (OR=1.83, CI%1.20-2.79, p<0.005; OR= 2.29, CI%1.1.49-3.51, p<0.001; OR=6.98, CI%4.61-10.70, p<0.001 for 12/16 weeks, 6 and 9 months, respectively). In this model, higher odds of owner-reported problem behaviour at 12 months were additionally associated with being a first-time owner (OR=1.93; CI%1.12-3.08, p=0.006), not seeing the dog’s mother on acquisition (OR=2.03, CI%1.12-3.68, p=0.02) and owner Openness personality trait score (OR=1.05, CI%1.01-1.09, p=0.02). The perception of deteriorating dog behaviour during the first year of a dog’s life may motivate owners to apply training with aversive components, warranting further education into the importance of consistent rewards-based training.