There are several varieties of prevention as well as treatment available for fleas and ticks.  Obviously, veterinary labeled products especially those sold exclusively from your veterinarian are proven to be more effective.  These products have more reputable research studies performed and guarantees generally exist if a problem were to arise. Animal

Medical Clinic carries:
Frontline Plus (topical) and Nexgard (oral).  Each form has its own benefits.  Both are proven to be effective against fleas and ticks.  In both forms, fleas and ticks can still bite your pet but those parasites will die soon thereafter.  Disease transmission, because long bloodmeals are prevented, is uncommon.

Disease transmission can still happen but most commonly this is seen with less effective products.  With oral prevention methods, a bite is required for the medication to work as the drug is in the blood.  Topical prevention methods can wash off easier so water exposure should be taken into consideration.  Topical methods can also kill fleas without a bite happening.

even pets that are rarely outside are still at risk for fleas and ticks.  People walking through the grass, pets going outside to urinate/defecate and other seemingly harmless and frequent acts can allow these parasites to enter a home and attach to your pet.