Due to the pet passport scheme (this part no longer applies as of january this year) we had no choice for the last 10 years but to frontline our pets in order to travel with them. Will definately look at trying garlic again now.
Other tips to consider are fresh ginger and a small slug of cider vinegar daily in their food for older dogs with arthritis and some dog experts swear by a day a week of fasting for dogs/cats as a natural worming alternative.
We can highly recommend the ginger and cider vinegar (though we also have our dogs on daily Glucosamine with MSN and Chondroitin) as a few years ago one of our dogs had regular arthritic attacks so severe she couldn`t walk and would scream if jolted at all. For the last 5 years since her new regime she`s not had any such problems and is just a slower, stiffer, but pain free, 13 year old!
Nicci