"perros o gatos"
Traducción:собаки или кошки
There is no problem using feminine form as generic for cats here. Note, собака in this sentence is also feminine, but is used for to describe unspecified male and female dogs. Male dogs is be псы. Technically, I don’t see a problem if someone said “псы и коты” (which, as I understand, still would be “perros y gatos”, but that would imply that you speak specifically about male animals)