Is Low Dosage Of Deworming Advisable For A 19 Months Old?

Hi, My daughter just turned 19 months and I had de-wormed her at 15 months when she got her measels vaccine (4 months ago). I was told to repeat the dose with 10ml after she turned 2. However, we have a puppy and my daughter plays with the puppy a lot, in the mud, etc. I often find her munching on things that she has picked up from the ground. I have a feeling that she needs to be de-wormed again now at 19 months because she has stopped putting on weight and i often find her scratching her buttocks. Would a 5ml dose be appropriate? I got a de-worming syrup free from the hospital but was told to give her the entire bottle (10ml) at 24 months.