Is NexGard Safe for Dogs? What Vets Recommend
If you’re a dog parent, you’ve probably heard about NexGard—that little chewable tablet that promises to keep fleas and ticks at bay. But like any responsible pet owner, you’re wondering: is NexGard safe for dogs? It’s a fair question! After all, you wouldn’t give your furry best friend just anything without doing your homework first. The good news is that NexGard has been around since 2013 and has become one of the most widely prescribed flea and tick preventatives by veterinarians across the country.
NexGard (afoxolaner) is an oral parasiticide that’s approved by the FDA and has helped millions of dogs stay free from fleas and ticks. But approval doesn’t mean it’s risk-free for every single pup, and that’s what we’re diving into today. Whether you’re considering switching to NexGard or you’ve already got a prescription, understanding how it works, who it’s best for, and what side effects to watch for will help you make the most informed decision for your four-legged companion.
Let’s break down everything vets want you to know about this popular flea and tick treatment, so you can feel confident about keeping your dog protected without unnecessary worry.
How NexGard Works
Understanding how NexGard works is the first step in determining whether it’s the right choice for your dog. Unlike topical flea and tick treatments that you apply to your dog’s skin, NexGard is an oral medication—a beef-flavored chewable tablet that your dog actually enjoys taking. This is a game-changer for many dog owners who struggle with getting their pups to cooperate during treatment time.
The active ingredient in NexGard is afoxolaner, which belongs to a class of pesticides called isoxazolines. Once your dog ingests the tablet, it gets absorbed into the bloodstream and distributed throughout the body. When fleas and ticks bite your dog, they ingest small amounts of afoxolaner, which overstimulates their nervous systems and causes paralysis, ultimately leading to their death. The medication targets the parasites’ nervous systems while being relatively safe for dogs because dogs’ nervous systems are less susceptible to the same effects.
What makes this approach particularly effective is that it works quickly. Fleas can be killed within 30 minutes of your dog taking NexGard, and the protection continues for a full month. Ticks are knocked out a bit more slowly—typically within 48 hours—but the month-long protection is still incredibly convenient compared to daily treatments or frequent reapplications.
FDA Approval and Safety Standards
Before any pet medication hits the market, it has to jump through some serious regulatory hoops. NexGard received FDA approval in 2013, which means it underwent rigorous testing to demonstrate both efficacy and safety. The FDA’s Center for Veterinary Medicine (CVM) requires pharmaceutical companies to provide extensive data on a medication’s effectiveness and potential risks before granting approval.
For NexGard specifically, the approval process included studies on various dog breeds, sizes, and ages. The medication is approved for dogs weighing at least 4 pounds and is available in multiple dose formulations to accommodate different sizes. The fact that it’s been in use for over a decade, with millions of doses administered annually, provides real-world evidence of its safety profile.
However, it’s important to note that FDA approval doesn’t mean a medication is completely risk-free. All medications carry some potential for side effects, and what’s safe for one dog might not be ideal for another. This is why veterinarians perform health assessments before prescribing NexGard and why they ask about your dog’s medical history, current medications, and any previous adverse reactions to medications.
The FDA’s Animal Health Literacy page provides excellent resources for understanding how medications are evaluated and approved for pets, which can help you feel more confident about prescription choices.
Common and Serious Side Effects
Let’s talk about the elephant in the room: side effects. Every medication has them, and NexGard is no exception. The good news is that most dogs tolerate it very well, but understanding the full spectrum of potential reactions will help you know what to watch for.
Common Side Effects
The most frequently reported side effects are generally mild and tend to resolve quickly. These include:
- Vomiting
- Diarrhea
- Decreased appetite
- Lethargy or tiredness
- Itching or skin irritation
These reactions typically occur within the first few hours after administration and usually subside within a day or two. Many dogs experience no side effects whatsoever. If you notice your dog isn’t eating well or seems a bit sluggish after taking NexGard, keep an eye on them and contact your vet if symptoms persist beyond 24 hours.
Serious Side Effects
While rare, some dogs have experienced more serious adverse reactions to NexGard. The FDA has received reports of neurological side effects, including seizures, tremors, and ataxia (loss of coordination). These serious reactions are uncommon, but they’re significant enough that pet owners should be aware of them.
In 2018, the FDA issued a safety communication about neurological adverse events associated with isoxazoline-based flea and tick treatments, including NexGard. The FDA reviewed over 1,600 reports of neurological issues but emphasized that the benefits of these medications for most dogs still outweigh the risks. However, this communication did lead many veterinarians to become more cautious about prescribing these medications to dogs with a history of seizures or neurological conditions.
If your dog has ever experienced seizures, tremors, or other neurological issues, it’s absolutely critical to discuss this with your veterinarian before using NexGard. There may be safer alternatives available, or your vet might recommend additional monitoring if the benefits of flea and tick prevention outweigh the risks in your specific situation.
Who Can Use NexGard
NexGard is approved for dogs weighing at least 4 pounds and at least 8 weeks of age. It comes in four different dose formulations to accommodate dogs of different sizes, which is great for customizing treatment to your individual pup.
Dogs Who Should NOT Use NexGard
While NexGard is safe for most dogs, certain situations warrant caution or avoidance:
- Dogs with a history of seizures: This is the most important consideration. If your dog has ever had a seizure, talk to your vet before using NexGard.
- Dogs with known isoxazoline sensitivity: If your dog has had a reaction to another isoxazoline product (like Credelio or Bravecto), NexGard might not be appropriate.
- Pregnant or nursing females: Safety in pregnant or lactating dogs hasn’t been fully established, so your vet will likely recommend alternatives.
- Dogs with severe illness: If your dog is currently dealing with a serious health condition, your vet might want to wait or choose a different treatment.
If your dog falls into any of these categories, don’t panic! There are plenty of other effective flea and tick prevention options available. You might explore what you can give your dog for allergies if you’re concerned about sensitivity issues, or discuss whether dogs can have Benadryl as part of a comprehensive approach to managing any adverse reactions.
Alternative Flea and Tick Prevention
If NexGard isn’t right for your dog, you have several excellent alternatives. Each has its own advantages and disadvantages, and your veterinarian can help you choose the best option based on your dog’s specific needs and health profile.
Topical Treatments
Medications like Simparica Trio, Bravecto Plus, and Revolution Plus are applied directly to your dog’s skin, usually between the shoulder blades where they can’t lick it off. These are effective and often work quickly, though some dogs dislike the feeling of the liquid on their fur.
Oral Alternatives
If you like the convenience of an oral medication but want to avoid isoxazolines, Capstar is an option that kills fleas quickly but requires more frequent dosing. There’s also Comfortis (spinosad), which is another oral option with a different mechanism of action.
Natural and Holistic Options
Some dog owners prefer natural approaches. Options include diatomaceous earth, essential oil-based products, and flea combs. However, these tend to be less effective than prescription medications and work best as supplementary prevention rather than primary protection. The ASPCA provides guidance on flea and tick prevention that includes discussion of various methods.
You can also learn more about how dogs get fleas to better understand prevention strategies, and if you notice your dog scratching excessively, understanding why dogs lick their paws can help you identify whether parasites might be the culprit.
What Veterinarians Recommend
Here’s what most veterinarians agree on when it comes to NexGard: it’s a safe and effective medication for the majority of dogs when used as directed. The American Veterinary Medical Association (AVMA) recognizes NexGard as an important tool in the fight against flea and tick-borne diseases.
Veterinarians appreciate NexGard for several reasons. First, it’s palatable—dogs actually like taking it, which means better compliance with treatment schedules. Second, it’s effective at both killing existing parasites and preventing new infestations. Third, it protects against not just fleas and ticks but also against certain tick-borne diseases that can be serious for dogs.
Most vets recommend the following approach:
- Health Assessment First: Before prescribing NexGard, your vet should take a complete history and perform a physical examination. They should specifically ask about seizure history and any previous medication reactions.
- Year-Round Prevention: Rather than using NexGard seasonally, vets typically recommend year-round protection. Fleas and ticks can survive indoors during winter, and the risk varies by location.
- Regular Monitoring: Bring your dog in for regular check-ups where your vet can assess whether the current flea and tick prevention is working well.
- Individualized Choices: Your vet recognizes that not all dogs are the same. What works perfectly for one dog might not be ideal for another, and that’s okay.
The American Animal Hospital Association (AAHA) also provides evidence-based guidance on flea and tick prevention that many veterinarians follow.
If you’re concerned about potential reactions to NexGard, you might also want to discuss whether products like Neosporin are safe for dogs in case you need to treat any skin irritation that might occur, or ask about how much Benadryl you can give your dog if your pup experiences an allergic reaction. Your vet can help you prepare a safety plan.
Frequently Asked Questions
Is NexGard safe for all dog breeds?
NexGard is approved for use in dogs of all breeds weighing at least 4 pounds. However, certain individual dogs—regardless of breed—might not be good candidates for NexGard. Dogs with a history of seizures or neurological conditions should not receive NexGard without explicit veterinary approval. Some breeds might be more prone to certain health conditions that could make NexGard less suitable, so always discuss your specific dog’s breed and health profile with your veterinarian.
Can I give NexGard to a puppy?
NexGard is approved for puppies at least 8 weeks old and weighing at least 4 pounds. The dose depends on your puppy’s weight, so your vet will prescribe the appropriate formulation. Puppies can benefit from flea and tick prevention just as much as adult dogs, and starting early helps prevent infestations before they become a problem.
How long does NexGard take to work?
NexGard begins killing fleas within 30 minutes of administration and can eliminate existing fleas within a few hours. Ticks take a bit longer—typically 48 hours—but the medication provides month-long protection against both parasites. This means you don’t have to wait to see results; your dog gets immediate protection.
What should I do if my dog has a reaction to NexGard?
If you notice mild symptoms like vomiting or diarrhea, monitor your dog closely and contact your vet if symptoms persist beyond 24 hours. If your dog experiences severe symptoms like seizures, tremors, loss of coordination, or difficulty breathing, seek emergency veterinary care immediately. Always report any adverse reactions to your vet, even if they seem minor.
Can NexGard be used alongside other medications?
Most medications are compatible with NexGard, but it’s essential to inform your veterinarian about all medications and supplements your dog is currently taking. Your vet can review potential interactions and advise whether it’s safe to use NexGard in combination with your dog’s other treatments.
Is NexGard better than topical flea treatments?
Both oral and topical flea treatments are effective; the choice depends on your individual dog’s needs and preferences. NexGard’s advantage is that it’s a chewable tablet—no mess, no application to the skin—but some dogs prefer topical treatments. Your vet can help you weigh the pros and cons for your specific situation.
How often do I need to give NexGard?
NexGard is given once monthly. You simply give your dog the appropriate dose based on their weight once a month, and it provides continuous protection. Many vets recommend setting a reminder on your phone or calendar to ensure you don’t miss a dose.
