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Oral Flea and Tick Prevention

Oral flea and tick prevention

Fleas and ticks have been dangerous and annoying pests for dogs and cats since the beginning of time. History was changed, and the world severely impacted by the lowly flea. Everyone is aware of the Bubonic Plague, transmitted from fleas living on rodents, and the sustained and deadly impact it had on Medieval Europe. Fleas and ticks can transmit a number of other serious, even deadly, diseases including Bartonellosis, Anaplasmosis, Lyme disease, and Rocky Mountain Spotted Fever, to name a few. Also, signs of flea allergy dermatitis can leave your pet itching, restless, and uncomfortable. Even the gut churning intestinal parasite, the tapeworm, gains entrance to our beloved pets through contact with fleas. Fortunately for us and our pets, we have never had better, easier to use, or safer options for flea and tick control than we have now.

Types of Preventatives

Flea and tick preventatives come in several options including topicals, collars, and oral products. Oral products are often preferred by dog owners, and will be the focus of this introductory article. Currently, Longwood Veterinary Center carries and recommends three different oral products– Nexgard, Simparica, and Simparica Trio. Each product provides monthly protection, and is offered in a tasty, easy-to-use treat that you give to your dog every 30 days.

Oral Flea and Tick PreventionNexGard

NexGard contains the active ingredient Afoxolaner, and is a member of the isoxazoline family. Afoxolaner effectively kills both fleas and ticks by attacking the central nervous system of the parasite by binding to GABA receptors. This sends the parasite into a state of hyperexcitation, and results in uncontrolled activity and the death of the flea or tick shortly after it takes a blood meal. Fleas are killed within eight hours of taking a blood meal from a treated dog, and ticks are killed within 48 hours.

The medication, as it is an oral product, cannot be washed off so you can safely bathe your pet or allow them to swim and play in the water in between doses. After ingestion by your pet, Afoxolaner is absorbed into the bloodstream and stored in tissues, then slowly released back into the bloodstream over a month-long period. The medication remains effective for 30 days. NexGard may be given to puppies as young as 8 weeks of age, as long as they weigh at least 4 lbs. The drug is generally well tolerated in all breeds, and may be given with or without food. Side effects including vomiting and decreased appetite have been noted, but are rare. Extremely rare side effects including seizure type events have been reported, therefore the drug is not recommended in dogs with pre-existing seizure history. Also, NexGard should not be given to cats.


Sarolaner, the active ingredient in Simparica, is also a member of the isoxazoline family, and works by interfering with GABA receptors, thus disrupting the central nervous system of the flea or tick. This product works very quickly, reportedly killing fleas within 3 hours, and certain species of ticks within 12 hrs. Simparica is also an oral product that is administered every 30 days. This product is safe to use in puppies of all breeds at as young as 8 weeks of age. Mild side effects such as vomiting and diarrhea have been infrequently reported. More series side effects such as seizures and signs of ataxia (difficulty walking) have been reported, but rarely. This can be a side effect of isoxazolines in general, and that is why the use of this class of drug is not recommended in pets with a known seizure history.

Simparica Trio

Simparica Trio is a unique oral medication that combines the active ingredient Sarolaner with moxidectin and pyrantel for effective flea and tick control. The addition of moxidectin and pyrantel provides monthly protection against heartworms and several gastrointestinal parasites in an easy-to-administer, tasty, and effective monthly pill. As with NexGard, neither Simparica nor Simparica Trio are safe to use in cats.

Year Round Flea & Tick Prevention

With so many safe and effective products available for flea and tick prevention, you will find it easy to protect your dog from disease-carrying parasites this summer and year round. The health of your cat is important too. Although safe, oral options are not yet available for use in cats, our office carries Seresto collars and topical Revolution, labeled for use in cats, that will keep your cat flea and tick free. We often offer manufacturer discounts or rebates through our website, or when purchasing in person at your pet’s wellness visit. Please contact the friendly staff of Longwood Veterinary Center for more information regarding flea and tick prevention.

-Dr. Corrina Snook Parsons