I have 3 dogs. 2 adults and 1 adolescent. In the past 3 weeks I've given 2 baths to each of the dogs, with flea shampoo (containing oatmeal for coat) and am still seeing 2 or 3 fleas within a day after bathing. All are scratching to some extent but the skin is not red or irritated looking under the fur. Only one ear was scratched enough to leave a mark and it's healing nicely. What else can I do? A collar will not work, they'll tear them off of each other.