Although cats and dogs can live amicably, inter-species conflict can result in poor welfare. Species introduction can impact the development of the cat-dog relationship. This study aimed to identify factors associated with owner reported ‘only desirable’ puppy behaviour (defined as the puppy being uninterested, ignored the cat and/or interacted in a calm way) following introduction to existing household cats, and to explore perceptions of the emerging cat-dog relationship. Owner-reported data collected as part of a longitudinal study of canine health and behaviour were used. Of 4678 puppies, 26.7% lived with at least one cat. Of the 1211 puppies who had been introduced to the household cat at the time of survey completion, playing (58.9%), being overexuberant or over-excited (56.6%), and chasing (48.6%) were the most common behaviours displayed towards cats. ‘Only desirable’ behaviours were shown by 7.3% of puppies. Multivariable logistic regression showed early (puppies aged <12 weeks), gradual introductions and living in a multi-dog household increased the odds of ‘only desirable’ behaviours. Qualitative analysis revealed two styles of introductions—owner-led and pet-led. Owners who led introductions anticipated amicable relationships between pets, whilst owners who let pets introduce themselves did not. Early, gradual, owner-led introductions of puppies to household cats should be encouraged.

Although cats and dogs can live amicably, inter-species conflict can result in poor welfare. Species introduction can impact the development of the cat-dog relationship. This study aimed to identify factors associated with owner reported ‘only desirable’ puppy behaviour (defined as the puppy being uninterested, ignored the cat and/or interacted in a calm way) following introduction to existing household cats, and to explore perceptions of the emerging cat-dog relationship. Owner-reported data collected as part of a longitudinal study of canine health and behaviour were used. Of 4678 puppies, 26.7% lived with at least one cat. Of the 1211 puppies who had been introduced to the household cat at the time of survey completion, playing (58.9%), being overexuberant or over-excited (56.6%), and chasing (48.6%) were the most common behaviours displayed towards cats. ‘Only desirable’ behaviours were shown by 7.3% of puppies. Multivariable logistic regression showed early (puppies aged <12 weeks), gradual introductions and living in a multi-dog household increased the odds of ‘only desirable’ behaviours. Qualitative analysis revealed two styles of introductions—owner-led and pet-led. Owners who led introductions anticipated amicable relationships between pets, whilst owners who let pets introduce themselves did not. Early, gradual, owner-led introductions of puppies to household cats should be encouraged.