Please read the parasite control discussions listed under dogs and cats as rabbits and rodents (guinea pigs especially) get the same types of external and internal parasites.  Prescription flea/tick/heartworm preventatives that we use for dogs and cats can treat a variety of parasite problems in our rabbits and rodents.  Remember to consult a veterinarian before applying any product to your rabbit or rodent to make sure it is safe as certain products can be very dangerous for our exotic pets.