Comb the dog with a special lice comb, or use a comb with very close teeth, from top to bottom. When grooming, the comb must touch the dog's skin. If you only groom your dog's coat and neglect the skin, some fleas will remain. Immediately after grooming, soak the comb in warm soapy water or an antiseptic solution to kill fleas on the comb. It can't be killed directly.

Pour equal parts lemon juice and warm water into a shallow bowl and mix well. Or cut the lemon into 4 pieces and put it in boiling water. Soak for 8 hours or overnight, then strain lemon juice into a bowl.
Dip your dog's hairbrush or comb in lemon juice and brush through your dog's hair. After the hair comes into contact with the brush, it will be covered with a layer of lemon juice. Make sure to brush your hair thoroughly and re-dip your brushes in lemon juice every time you brush. Repeat this process once a day for 3 days. It is necessary to comb the dog's hair more at ordinary times. In addition to making the hair smoother, it can also comb out some small fleas.