Investigating canine colour preference through a free choice preference test : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Animal Science at Massey University, Manawatu, New Zealand

Abstract

Dogs are one of the most common pets worldwide, and promoting their welfare is a key concern for many owners. Numerous studies have been performed investigating dogs’ cognitive and sensory capabilities, from which we know that they have poorer vision than humans, including dichromatic vision and red–green colour blindness. Instead, they rely heavily on their other sensory modalities, such as olfaction and low-light detection. Little research has investigated whether dogs show preferences for less dominant sensory cues, such as colour vision, and how this may be integrated into their environment to enhance welfare. This study aimed to investigate whether dogs display a colour preference when presented with three different coloured stimuli in a free-choice preference test based on their visual spectrum. Sixteen domestic dogs were included in this study. Of these, two were used in the pilot study, one was excluded due to a lack of habituation prior to testing, and thirteen were included in the main study. Three coloured bowls containing food (red, blue, and yellow) were presented simultaneously in fixed locations (left, middle, right) over three testing days and a total of 18 trials. Behaviours measured included first bowl visited, number of visits, duration of visits, percentage of time spent interacting with each bowl, latency to approach each bowl, and the first bowl visited in each trial. Data were analysed using either chi-square tests, Fisher’s exact tests, ANOVA, or Poisson regression, with dogs as either a repeated measure or fixed effect, to assess both individual and population preferences. No significant effect of colour was observed at either the population or individual level. Some individuals showed a tendency to prefer red, and overall, dogs approached the red bowl faster than others. However, there was a strong preference for the right-sided location at both the individual and population levels. This location preference became more prominent over repeated trials, possibly overriding any potential colour preferences. The presence of some weak individual colour preferences indicates that colour may play a role in decision-making for some dogs, warranting further research, including more trials and a larger sample size. These findings highlight that while dogs are capable of discriminating colours, it may not be a primary driver of canine choice behaviour. Understanding these patterns has practical implications for promoting canine welfare. Colour alone may not be useful to enhance welfare, but it may still be incorporated alongside other sensory features to support positive experiences.