The fact of the matter is, many cats don't need to be bathed at all, since they are masters at grooming and cleaning themselves. However, if your cat has fleas, if he's an outdoor kitty who has stepped in something vile, or if he just looks and feels dirty, then it may be time to give that kitty a bath. If your kitty is very young, then you should wipe him off with a wet or damp washcloth instead of giving him a full-on bath.   Talk to your vet about when is a good time to give your little kitty a full-on bath. According to the Animal Compassion Network, you should wait until your kitty is at least 8 weeks old before giving him a full-on bath.  One benefit to bathing your kitty when he's young is that this will make him used to bathing if he routinely gets dirty. Just remember that cats spend about 30% of their time grooming and that they really shouldn't be bathed more than once or twice a year unless they get really dirty. Even the most mild-mannered kittens will protest a bit when you bathe them, especially if it's for the first time. To protect yourself from getting scratched by your favorite furry creature, you should make sure to trim his nails a bit so he's less likely to hurt you when you're bathing him. Though a kitten's scratches may not be as ferocious as those of a full-grown kitty, you could still get hurt. It's better to do this to keep yourself safe, even if your kitty protests a bit.  You shouldn't trim your kitten's nails right before you bathe him, however. Do it the day before or at least a few hours before. A lot of cats get a bit feisty and riled up after their nails are trimmed, and you want your little critter to be in a calm frame of mind before you begin the bath. If you haven't trimmed your kitten's nails yet, you're better off leaving quite a bit of time between nail trimming and bathing — even a full day. Nail trimming can be a new and scary experience for a young kitty, and you don't want to make it worse by adding a bath into the mix. Before you soak your little kitten, you...

TL;DR in Vietnamese:
Xác định thời điểm thích hợp để tắm cho mèo. Cắt móng cho mèo. Chải lông cho mèo. Đừng tắm cho mèo khi đang mặc áo ba lỗ hở tay và ngực. Chuẩn bị dầu gội dành cho mèo. Chuẩn bị dụng cụ sẵn sàng để tắm cho mèo. Làm cho bồn tắm trở nên hấp dẫn hơn đối với mèo. Tắm cho mèo khi chúng ở trạng thái bình tĩnh.