Learn Swedish: Jag föredrar rasen vars hundar är lydiga. - I prefer the breed whose dogs are obedient.

Just like with other possessive words (such as min, din, or hans), the noun that follows vars must be in the indefinite form. Because vars already acts as a specific owner, Swedish requires the indefinite hundar instead of the definite hundarna.

Can vars be used for animals and categories, like rasen, or is it just for people?

Yes, vars can be used for anything! While English speakers sometimes hesitate to use "whose" for non-humans or objects, Swedish happily uses vars for people, animals, objects, and abstract concepts alike.

Why does the adjective lydiga end in an -a here?

It ends in -a because it describes the plural noun hundar. Adjectives in Swedish take the -a suffix when modifying plural nouns, regardless of whether that noun is definite or indefinite.

How does the verb föredrar translate to "prefer"?

Föredrar is the present tense of föredra, which is a compound verb made of för (before) and dra (to pull or draw). If you think of it literally as "to draw something before" something else, it makes perfect sense as "to prefer"!