Dog owners should avoid using flea treatments containing permethrin or pyrethrins around cats or sensitive breeds, and be cautious with isoxazolines in dogs with neurological issues.
Natural flea preventatives such as citrus oils, cedarwood, geraniol, or diatomaceous earth are generally considered the least toxic options for dogs when used properly.
The safest flea treatment for dogs depends on individual factors like breed, age, health, and environment; consult your veterinarian to choose the best option and always follow label instructions.