Oral and Topical Flea Treatments

Flea infestations can be treated using a variety of products, the most common of which are oral and topical flea treatments.  In the past, topical preventatives such as fipronil (Frontline), fipronil and methoprene (Frontline Plus®) and imidacloprid (Advantage®) were the leaders in flea and tick prevention.  In recent years, oral flea treatments have increased in popularity, including spinosad (Comfortis®) and nitenpyram (Capstar®).  

With all the flea and tick products out there, choosing the best one for your pet can seem overwhelming.  So which one is better for your pet?

Topical flea treatments, such as fipronil, fipronil with methoprene, and imidacloprid, have been recommended by veterinarians for years.  These products have been proven effective in the treatment of fleas, and some are labeled for tick control as well.  Topical flea and tick treatments are easy to apply—simply empty the contents of the correct dosage applicator in between your pet’s shoulder blades, making sure to make contact with the skin.  The chemicals in topical flea and tick treatments are not absorbed into the blood stream at any time.  Instead, chemicals collect in the oils on your pet’s coat, gradually moving into the skin by way of the hair follicles.  Flea and tick fighting ingredients are then able to spread throughout the body through a process known as translocation.  This entire process takes anywhere from 24-48 hours and remains effective for up to one month.

Unfortunately, when applying topical flea products, owners must be sure to refrain from bathing their pets two days before and two days after application.  Because these products come in a liquid form, they can be washed away with water if they are not given enough time to collect in the oils of the skin.  Additionally, if there is not a sufficient amount of oil on your pet’s skin, the flea and tick fighting ingredients have little or no way to move throughout your pet’s body.  Another disadvantage of using topical medications is the mess associated with them.  Many customers complain about the oily residue that remains on their pet after application.  Chemicals from the treatment can be rubbed off by holding or even making contact with your pet.

Oral flea treatments, like spinosad, have become much more popular in recent years as they are extremely easy to administer and take effect almost immediately.  Oral flea preventatives start to kill fleas in as little as thirty minutes and remain effective for up to one month.  Once the digestive system breaks down the flea treatment, the chemicals are absorbed into the bloodstream, allowing them to circulate throughout the body quickly.   Since this type of flea prevention is given orally, there is no messy residue to deal with, making it ideal for households with children or households where pets are handled often.

The main disadvantage of oral flea medications is the increased likelihood of side effects.  Because chemicals are released directly into the bloodstream, there is more concern for potential side effects, including vomiting, decreased appetite, and lethargy.  Some pet owners may find it difficult to administer an oral product as many pets have a hard time swallowing pills and tablets.  Finally, most oral flea medications are labeled for fleas only and are not an effective method for controlling and killing ticks.

Both oral and topical flea treatments have their advantages and disadvantages.  Each type has been proven effective in controlling flea infestations, and both are recommended by veterinarians on a daily basis.  Ultimately, the decision comes down to what method works best for you and your pet. 


Our information is not intended to replace the advice of your veterinarian.  Do not use this information for diagnostic purposes. Always take your pet to your veterinarian to obtain a diagnosis and course of treatment.