According to their records, afoxolaner (the active ingredient in NexGard) has caused 1,261 deaths by the time of writing this article in April 2022. NexGard Spectra contains milbemycin oxime in addition to afoxolaner — this pairing is responsible for 6,455 reported deaths to date.
Yes, Nexgard is an incredibly safe and effective prevention for fleas, ticks, and mites. However, because Nexgard is ingested and absorbed into the bloodstream, rather than applied to and spread by the oils of the skin, the few reactions that do occur can seem more dramatic.
NexGard® Recalls & Controversies
Although there have not been any FDA recalls for NexGuard®, the FDA has put out an alert for pet owners and veterinarians.
“NexGard (afoxolaner) is one of the isoxazoline class of parasiticides. Please do NOT use any of them again. There are now two isoxazoline-related class-action lawsuits in North America — one in Quebec and the other in New Jersey. The FDA finally has required warnings on the labels and product inserts.
These products are safe to use in the majority of pets, but there are some pets that cannot tolerate the medication (specific liver disorders, pre-existing seizure disorders).
Seizures have been reported in dogs receiving isoxazoline class drugs, even in dogs without a history of seizures. Therefore, use with caution in dogs with a history of seizures or neurologic disorders. The safe use of NexGard in breeding, pregnant or lactating dogs has not been evaluated.”
In the US field study, one dog with a history of seizures experienced a seizure on the same day after receiving the first dose and on the same day after receiving the second dose of NexGard. This dog experienced a third seizure one week after receiving the third dose.
Simparica is an excellent choice for flea and tick protection. The monthly chew also comes with an option for heartworm protection, too, as Simparica Trio. But while Simparica is usually safe flea and tick treatment for dogs, it shouldn't be prescribed to dogs with a history of 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.
NexGard is given as a tablet of the appropriate strength for the dog's bodyweight. NexGard kills fleas within 8 hours and ticks within 48 hours. After being given, its actions last for at least 5 weeks against fleas and up to one month against ticks.
Nexgard can kill 99% of all infections in a single treatment. The product kills eggs, larvae, and full-grown parasites making it highly effective in protecting your dog's health.
NexGard allergies in dogs occur when dogs have an allergic reaction to or suffer from side-effects of this popular flea and tick treatment. The active ingredient, afoxolaner, may not agree with all dogs that ingest this oral preventative.
Both products are safe for dogs when following directions and have been approved by the FDA to treat and prevent flea and tick infestations. However, unlike Bravecto, Nexgard has not yet been evaluated for use in breeding, pregnant, or lactating dogs.
Many flea and tick medications are manufactured in a once-monthly topical application or pill. If you miss that monthly dose, your pet is at risk of getting flea or tick bites.
It can take anywhere from 12 to 48 hours for the tick to die with these products. Since it takes at least 48 hours for a feeding tick to start regurgitating and transmitting disease, using Nexgard or Bravecto will effectively prevent tick-borne disease.
In short, yes, your dog needs flea and tick prevention during the winter months. While it's true that tick and flea species slow down during the winter when outdoor temperatures drop, fleas can easily find their way in your home and onto your pet during the winter.
Best Overall: Frontline Plus Topical Treatment
The most frequently recommended is a topical treatment. Frontline Plus is a well-established product: “For more than 20 years, veterinarians and pet owners have been using Frontline Plus for Dogs to effectively prevent, treat, and control fleas,” writes DogProductPicker.
The most common reason is that the fleas are being killed and the dog is no longer being bitten by them. This can cause the dog to feel itchy and uncomfortable, which may lead to restlessness. Additionally, the chemicals in some flea treatments can be irritating to dogs, leading to discomfort and restlessness.
It has minimal side effects, and has been shown to be safe at up to 5 times the recommended dose. In a 90-day field study, 415 dogs were administered afoxolaner and no serious adverse reactions were observed with NexGard. The most frequent adverse reaction was vomiting, with 17 dogs experiencing that reaction.
4.5% of dogs receiving Simparica. 14.8% of dogs receiving Bravecto. 12% of dogs receiving Nexgard.
Simparica, NexGard, Bravecto & Credelio may not increase the number of seizures, but the risk is real. Whether you use it will depend on how likely it is that your dog will get a tick and your confidence in other methods of prevention.
If a dog vomits within 2 hours of administration of a Nexgard tablet, a new tablet should be given. If vomiting occurs after 2 hours, re-dosing is not necessary. There are no known drug interactions with afoxolaner.
Here's what you should know. The FDA recently released an alert that reads: “The FDA considers products in the isoxazoline class to be safe and effective for dogs and cats.” but went on to warn pet owners and veterinarians about potential neurological reactions to the isoxazoline class of drugs.
Is Bravecto, NexGard, Simparica, Seresto and K9 Advantix II Safe for Australian Shepherds? Ultimately this is a question only you and your veterinarian can answer. According to the available FDA adverse reaction data, most pets do fine on these medications.