Translation:Are dogs more affectionate than cats?
Yes, but generally for such cases the plural is implied. Chinese uses a lot of measure words 量词. For example, in English one would say "three apples" while in Chinese one says "three measure word strawberries" 三颗草莓.
In the same way the sentence you suggested would be translated as 一只狗会比一只猫更热情吗？or any acceptable equivalent, but they would likely use 一只 i.e. a 量词.