Fleas are a problem, and they are difficult to get rid of completely - esp with multiple dogs. If one has fleas, I'm sure they ALL do. If you are limited to store-bought or over-the-counter remidies, it's ALOT of work to get rid of them completely and keep them away. Just getting them off the dog won't do it - they are in your carpets and furniture, even if the dogs aren't on the furniture. Preventive meds like Sentinal or Advantage probably work the best, and cover multiple pest hazards.

Can't remember the name, but there are quite a few monthly appications of flea treatment that can be found inexpensively in the pets stores, that work pretty well.

However, adding a bit of garlic to their food probably can't hurt the allergic one, and is somewhat of a natural flea deterent.