"Big dog, big cat. Big mice, big cows."
Translation:बड़ा कुत्ता, बड़ी बिल्ली। बड़े चूहे, बड़ी गायें।
You don't. In Hindi, both rats and mice (or rather, the many species of rodents that are called mice in English and the species that are called rats) are all considered varieties of the same animal that's called a चूहा.
However, in modern technical Hindi and especially when translating from English, a Sanskrit-borrowed word मूषक (which has the same root as the English 'mouse' going back to Proto Indo-European) is used for 'mouse' and चूहा for 'rat'. Still, to a layperson, मूषक and चूहा are synonyms, with मूषक being the more 'formal' word.