Como dizer "pelo de gato / cachorro" em inglês

Generally, pets have fur, not hair. And certainly, you would say fur, and not hair, for cats and dogs. If you want a basic answer, that's it. However, you would say a "long-haired/short-haired/medium-haired cat". This probably comes from a more technical background. Fur is technically still a hair. And, if you were referring to one strand of it, you would say "a hair", or "a cat hair". "Coat" is correct when referring to the whole animal. But you wouldn't say "a long-coated cat". (Wordreference)