Bravecto vs NexGard: Active Ingredients and Effectiveness
When it comes to **flea and tick treatments**, the active ingredients play a pivotal role in how well these products work and how they affect your pet’s health. Both Bravecto and NexGard are highly effective, but they contain different active ingredients, and understanding these can help you choose the best option for your pet. **But before we dive into the specifics, it’s important to note that ticks in South Africa can pose a serious health risk to your pets.** If you’re curious about why these tiny creatures are such a big problem, you can **read more about ticks in South Africa** here. Understanding the risks can help you make a more informed decision when selecting the best flea and tick treatment.NexGard: Afoxolaner
NexGard contains **afoxolaner**, a member of the **isoxazoline** class of drugs. Afoxolaner works by interfering with the nervous system of fleas and ticks. It inhibits the action of neurotransmitters (gamma-aminobutyric acid, or GABA), causing the parasites to become hyperexcited, which ultimately leads to paralysis and death. How It Works: When a flea or tick bites your dog, it ingests the medication through the blood. The active ingredient targets the parasite’s nervous system, causing them to lose control over their muscles, resulting in paralysis and death. Speed of Action: **Afoxolaner** works quickly to eliminate fleas, often starting to kill within **30 minutes** of administration. This makes it ideal for situations where you need fast relief. Duration of Protection: **NexGard** provides **one month of protection** per dose. This makes it ideal for pet owners who are okay with administering monthly treatments. Safety Profile: **NexGard** is generally well tolerated, with a low incidence of side effects. It is also safe for puppies as young as **8 weeks old**. Common side effects may include mild gastrointestinal upset or lethargy, but serious reactions are rare.Bravecto: Fluralaner
Bravecto uses **fluralaner**, another isoxazoline-class insecticide, which works in a similar way to **afoxolaner**, but has a few differences in its action. How It Works: **Fluralaner** targets the same **GABA** neurotransmitter in fleas and ticks, causing paralysis and death. However, **fluralaner** remains in the bloodstream much longer than **afoxolaner**, offering prolonged protection. Speed of Action: While **fluralaner** also works quickly, it takes about **2 hours** to start killing fleas and ticks, a bit slower than **afoxolaner**. But the major difference is its long-lasting effect. Duration of Protection: One dose of **Bravecto** provides **up to 3 months of protection**. This extended protection is perfect for pet owners who want a more convenient, less frequent dosing schedule. Safety Profile: **Bravecto** shares a similar safety profile with **NexGard**. It is safe for puppies as young as **8 weeks old**. Side effects are rare, but when they occur, they are typically mild and might include gastrointestinal upset (e.g., vomiting or diarrhea) or lethargy.Key Differences in Active Ingredients:
| Feature | NexGard (Afoxolaner) | Bravecto (Fluralaner) |
|---|---|---|
| Class of Drug | Isoxazoline | Isoxazoline |
| Duration of Protection | 1 month per dose | 3 months per dose |
| Speed of Action | Starts within 30 minutes | Starts within 2 hours |
| Primary Target | Fleas and ticks | Fleas, ticks, and some mites |
| Metabolism | Rapidly absorbed and eliminated in 1 month | Long-lasting in the bloodstream for 3 months |
| Formulation | Chewable tablet | Chewable tablet or topical formulation |
| Side Effects | Generally well tolerated; rare side effects like vomiting or lethargy | Generally well tolerated; rare gastrointestinal upset in some pets |
Why Do the Active Ingredients Matter?
Understanding the differences between **afoxolaner** and **fluralaner** can help you make a better decision for your pet:- Speed and Duration: If you want fast relief from fleas and are okay with monthly dosing, **NexGard** might be the better choice as it works within **30 minutes** and lasts for a month.
- Convenience: If you prefer less frequent dosing and want the convenience of **3 months of protection**, **Bravecto** might suit your needs better.
- Parasite Coverage: Both products are effective against fleas and ticks, but **Bravecto** also offers protection against some types of mites, making it a more versatile option in certain cases.
Choose Bravecto if:
- Dogs that hike, farm, or go camping face heavy tick exposure — Bravecto handles it effortlessly.
- Long-lasting cover matters to you, especially with 3–6 months of protection per dose.
- Monthly reminders slip your mind and you prefer a set-and-forget solution.
- Safe use during pregnancy, breeding, or lactation is a priority in your household.
Choose NexGard or NexGard Spectra if:
- You prefer a simple monthly routine.
- Your dog loves chewable “treat-style” meds.
- You want added worm protection (Spectra includes heartworm + intestinal worms).
- You have a very young puppy (NexGard is safe from 6 weeks old).
Active Ingredients (What Actually Does the Killing)
Both products belong to the same chemical family (isoxazolines), but work slightly differently.
| Product | Active Ingredient | What It Does | Manufacturer |
|---|---|---|---|
| Bravecto | Fluralaner | Powerful tick, flea & mite killer; long-lasting. | MERCK Animal Health |
| NexGard | Afoxolaner | Fast-acting chew that kills fleas & ticks. | Boehringer Ingelheim (formerly Merial) |
| NexGard Spectra | Afoxolaner + Milbemycin Oxime | Kills fleas, ticks + worms (roundworm, hookworm, whipworm, heartworm). | Boehringer Ingelheim |
Which Is Safer for Puppies, Pregnant Dogs & Sensitive Breeds?
Puppies
- Bravecto: Safe from 8 weeks (chew) and 6 months (spot-on depending on region — confirm with vet).
- NexGard: Safe from 6 weeks old — ideal for very young pups.
Pregnant, Breeding & Lactating Dogs
- Bravecto: Tested and approved safe for breeding, pregnant, and lactating dogs (according to Bravecto SA product information).
- NexGard: Safety not yet evaluated in pregnant, lactating, or breeding dogs.
Dog Breeds With Sensitivities
Both products are considered generally safe for all dog breeds — including Collies — when used correctly, but consult your vet if your dog has a history of seizures.
How Long Each Product Lasts
| Product | Protection Duration |
|---|---|
| Bravecto Chew | 12 weeks (3 months) |
| Bravecto Spot-On | 4 months for ticks / 6 months for fleas |
| NexGard | 1 month |
| NexGard Spectra | 1 month |
Winner: Bravecto — fewer treatments per year means more time for braais, road trips, and convincing your dog not to chase the neighbour’s hadeda.
Speed of Kill (Crucial for Tick Fever Prevention)
Tick fever (babesiosis, ehrlichiosis) is common in SA — especially on the Highveld, KZN, and the bushveld. Fast kill time matters.
- Bravecto: Begins killing ticks within 8 hours; reaches 90–100% efficacy within 12 hours (according to Bravecto SA product information).
- NexGard: Starts killing fleas within 4 hours and ticks within 8–12 hours (according to NexGard SA label).
Both work fast — Bravecto just stays fast for longer.
Parasites Each Brand Protects Against
| Parasite | Bravecto | NexGard | NexGard Spectra |
|---|---|---|---|
| Ticks | ✔️ | ✔️ | ✔️ |
| Fleas | ✔️ | ✔️ | ✔️ |
| Mites | ✔️ | Some | Some |
| Heartworm | ❌ | ❌ | ✔️ |
| Intestinal Worms | ❌ | ❌ | ✔️ |
Winner for all-in-one protection: NexGard Spectra.
Answers to Frequently Asked Questions
No product is “safer” across the board. Both are considered safe when used correctly, but some dogs tolerate one better than the other. Your vet will guide based on your dog’s health history.
Yes, but only under veterinary guidance. Timing matters to avoid gaps in protection.
Very rarely. Isoxazoline products have reported neurological side effects in sensitive dogs. Discuss with your vet if your dog has a seizure history.
Both kill ticks effectively. Bravecto offers longer-lasting protection, which some vets prefer in high-risk areas.
Bravecto contains fluralaner, an insecticide and acaricide, that hampers the nervous system of pests. When fleas and ticks feed on your dog, they ingest small amounts of fluralaner and die. On the other hand, NexGard contains afoxolaner as its key ingredient. Afoxolaner is also an insecticide that kills fleas and ticks by causing hyperexcitation and uncontrolled activity in the nervous system.
Bravecto has been tested and approved. NexGard has not yet been evaluated.
No. NexGard® and NexGard SPECTRA® must only be used for dogs.
Final Recommendation
If your priority is ticks & fleas only: Either option will do the job reliably, since both excel at parasite control.Looking for long-lasting convenience? Bravecto is ideal, offering months of protection with minimal dosing.
Need full parasite coverage (ticks, fleas, worms)? NexGard Spectra provides the most complete all-in-one solution.
Caring for a pregnant or breeding dog? Bravecto is approved for these cases, while NexGard has not been tested for them.
Helpful External Resources
🦴 Still not sure which product suits your pet best?
Vet’s Note: Cats Need Tick & Flea Protection Too
Ticks and fleas don’t only affect dogs — cats are just as vulnerable, especially those who roam outdoors.
Untreated infestations can lead to skin infections, allergies, anaemia, and in severe cases, life-threatening tick-borne disease.
Bravecto for Cats offers long-lasting protection (up to 3 months per dose), while NexGard’s feline products target fleas and certain worms depending on the formulation.
Always choose a treatment specifically made for cats, as dog products can be dangerous for them.
Most tick and flea issues improve quickly with **vet-approved parasiticides, proper dosing, and supportive care**.
Never give cats human medicine or dog-specific tick treatments.
Bravecto South Africa – For Cats — long-lasting tick and flea protection designed specifically for feline safety.
NexGard Combo for Cats — a broad-spectrum topical for cats that treats fleas, ticks, roundworms, hookworms, lungworm, and tapeworm.
MSD Vet Manual – Ticks of Cats — authoritative veterinary guidance on tick species, diseases, symptoms, and prevention.
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