For dogs with a history of seizures, consult your vet for alternatives to isoxazoline-class meds (like NexGard, Bravecto, Simparica, Credelio), as they're linked to neurological issues; Revolution (selamectin) or Sentinel (milbemycin/lufenuron) are often recommended by owners and vets as safer options, with some using topical or non-toxic methods like Seresto collars or Diatomaceous Earth for flea/tick control, but always get veterinary guidance for seizure-prone pets.
For pets with a history of seizures living in tick areas
These pets may have a greater risk of side effects. Your vet can discuss alternative products, such as Advantix (for dogs only) or a Seresto collar (for dogs and cats).
Specific studies with NexGard and NexGard SPECTRA have not been conducted in dogs with epilepsy, and therefore any potential effect of treatment on seizure frequency is unknown. It is recommended to use isoxazolines with caution in dogs with a history of epilepsy or any other seizure disorder.
Seizures can occur as a potential side effect of some flea and tick medications, particularly those containing isoxazoline. While these medications are generally safe, some animals, especially those with a prior history of seizures or underlying health problems, may be more susceptible to adverse reactions.
There are several oral prescription flea and tick medications that are safe for dogs. These preventatives come in pill and chew forms. Your vet can help you find the right one for your pup's age. Credelio Quattro is an excellent choice for flea and tick protection.
Both products are safe for dogs when following directions and Nexgard has been approved by the FDA to treat and prevent flea and tick infestations. However, unlike Frontline Plus, Nexgard has not yet been evaluated for use in breeding, pregnant, or lactating dogs.
Cedarwood oil solution (10 drops per 1 ounce of water) can be applied to both pets and the environment once to twice daily. Cedarwood mulch is a helpful deterrent for landscaping. For moderate infestations, Dr. Trish uses Revolution and for severe infestations, she recommends Nexgard.
Adverse reactions in dogs treated with SIMPARICA TRIO included diarrhea and vomiting. In one well-controlled laboratory study, one dog had a seizure 16 days after administration of SIMPARICA TRIO.
True toxicity from ingestion of Frontline Plus is rare in dogs. But if it happens, more serious signs, in addition to the ones listed above, may include: Tremors. Seizures.
The most frequently reported factors included stress‐related situations, sleep deprivation, weather, and hormonal factors. In dogs with focal onset seizures, the number of precipitating factors was 1.9 (95% CI 1.1‐3.4) times higher compared to dogs with generalized seizures.
Both products are safe for dogs when following directions and have been approved by the FDA to treat and prevent flea and tick infestations. While Simparica was trialed and not approved, Nexgard has not yet been evaluated for use in breeding, pregnant, or lactating dogs.
All BRAVECTO products contain fluralaner, which is a member of the isoxazoline class. This class has been associated with neurologic adverse reactions including tremors, ataxia, and seizures. Seizures have been reported in dogs receiving isoxazoline class drugs, even in dogs without a history of seizures.
Use NexGard PLUS with caution in dogs with a history of seizures or neurologic disorders. For more information, click here for full prescribing information. Following the use of HEARTGARD Plus (ivermectin/pyrantel) in dogs, digestive and neurologic side effects and itching have been reported.
Supplements such as CBD oil, omega-3-rich fish oil, magnesium, melatonin, and vitamin B6 are commonly used to support dogs with seizures. These supplements may help support brain health and reduce seizure triggers when used alongside veterinary treatment.
Dogs can also become exposed at toxic quantities through the ingestion or absorption of household insect sprays, foggers, and granules. Common brands of pyrethrins/pyrethroids include: Advantix™ Vectra 3D®
Our team of veterinary professionals recommend Comfortis as a potentially safer flea prevention for many dogs who experience seizures.
Frontline Side Effects
There are many concerns about possible side effects, the most common being skin reactions like hair loss, itching, and redness, and neurological issues like uncoordinated movement and lethargy. However, these side effects are not addressed anywhere on the US website for Frontline.
Overdosing or over-treating your dog with K9 Advantix II or any other flea and tick medication can lead to serious health problems, including toxicity, seizures, and even death.
The best prescription alternatives to Simparica Trio include NexGard PLUS, Interceptor Plus with Bravecto or NexGard, and Credelio Quattro. These are made by trusted veterinary pharmaceutical companies like Boehringer Ingelheim, Elanco, Zoetis, and Virbac.
Four flea and tick products may cause seizures, tremors, and lost coordination in some cats and dogs. Food and Drug Administration officials have received thousands of reports of adverse events connected with three products—Bravecto, Nexgard, and Simparica—containing drugs in the isoxazoline class.
The biggest factors in finding the right flea and tick medication for your pet are your pet's age, weight, and overall health. Some flea and tick prevention methods aren't safe for puppies and kittens, pets under a certain size or weight, or pets that are very old or in poor health.
Final Thoughts. As you can see, both Nexgard and Simparica are extremely good and effective flea and tick treatment and they do not have a major difference between them. But that being said, Simparica does kill an additional tick specie and is relatively faster in eliminating fleas and ticks.
– what smells do fleas absolutely hate? Due to their sensitive sensory systems, certain natural scents like lavender, eucalyptus, and citronella are extremely off-putting to fleas. These scents not only repel adult fleas but can also disrupt their ability to detect a host, effectively breaking the cycle of infestation.
Natural Alternatives for Flea and Tick Prevention. Diatomaceous earth is a natural powder made from fossilized aquatic organisms. It's non-toxic to pets and humans but deadly to insects. When applied to your pet's fur and your home's carpets and bedding, it dehydrates and kills fleas and ticks.