Bravecto Flea and Tick for Dogs: Complete Safety & Dosage Guide
Complete guide to Bravecto flea and tick for dogs covering dosage, side effects, safety data, cost, and alternatives. Vet-reviewed 2026 guide.
What Is Bravecto Flea and Tick for Dogs?
Bravecto is a long-acting parasiticide manufactured by Merck Animal Health containing the active ingredient fluralaner, which belongs to the isoxazoline drug class. Unlike monthly flea and tick preventives, Bravecto's chewable tablet formulation provides 12 weeks of continuous protection against fleas and several tick species with a single dose. The topical solution variant covers 8 weeks. This extended duration has made Bravecto flea and tick for dogs one of the most prescribed parasiticides in veterinary medicine since its FDA approval in 2014.
Bravecto is available in two formulations for dogs:
- Chewable tablets — 12-week protection, available in five weight-specific dosages (5.1–11 lb, 11.1–22 lb, 22.1–44 lb, 44.1–88 lb, 88.1–123 lb)
- Topical solution — 8-week protection, applied to the skin between the shoulder blades, available in matching weight ranges
As of 2026, Bravecto remains one of the longest-lasting systemic flea and tick preventives available by prescription, alongside competitors like NexGard (afoxolaner, monthly) and Simparica Trio (sarolaner/moxidectin/pyrantel, monthly).
How Does Bravecto Work? Mechanism of Action
Drug Class: Isoxazoline parasiticide
Active Ingredient: Fluralaner
Target: Invertebrate ligand-gated chloride channels (GABA-gated and glutamate-gated)
Fluralaner works by binding to and blocking gamma-aminobutyric acid (GABA)-gated and glutamate-gated chloride ion channels in the nervous systems of fleas and ticks. These channels exist only in invertebrates — dogs and other mammals have structurally different chloride channels, which is why fluralaner exhibits selective toxicity against parasites while remaining safe for canine use at approved dosages.
When a flea or tick bites a Bravecto-treated dog, it ingests fluralaner present in the dog's blood and tissue fluids. The drug causes uncontrolled hyperexcitation of the parasite's central nervous system, leading to rapid paralysis and death. Fleas are typically killed within 2 hours of attachment; ticks within 12 hours. Critically, parasites must bite the dog to receive the lethal dose — Bravecto does not repel parasites or prevent attachment.
According to the Merck Veterinary Manual, fluralaner is absorbed systemically after oral administration, distributes widely to fatty tissues, and has an exceptionally long elimination half-life of approximately 15 days in dogs. This extended half-life is what allows the 12-week dosing interval.
FDA-Approved Uses and Common Off-Label Applications
FDA-approved indications for Bravecto in dogs include:
- Treatment and prevention of flea infestations (Ctenocephalides felis)
- Treatment and control of the American dog tick (Dermacentor variabilis)
- Treatment and control of the brown dog tick (Rhipicephalus sanguineus)
- Treatment and control of the lone star tick (Amblyomma americanum)
- Aid in the treatment and control of flea allergy dermatitis (FAD) by eliminating the flea burden
Common off-label uses (prescribed at veterinarian discretion) include:
- Demodectic mange (Demodex canis) — Multiple peer-reviewed studies, including research published in the Parasites & Vectors journal, have demonstrated fluralaner's efficacy against generalized demodicosis, often as a single oral dose. This has become a common off-label application in veterinary dermatology.
- Sarcoptic mange (Sarcoptes scabiei) — Bravecto has shown high efficacy against sarcoptic mange mites in clinical trials.
- Ear mite infestations (Otodectes cynotis) — Used in some multi-dog households where topical ear mite treatments are impractical.
Off-label use is legal and common in veterinary medicine but should always be directed by your veterinarian, who will weigh the evidence and determine appropriate dosing.
Bravecto Dosage by Dog Weight and Condition
The standard dosage of fluralaner for flea and tick prevention is 25–56 mg/kg (11.4–25.4 mg/lb) administered orally once every 12 weeks. Your veterinarian will prescribe the exact chewable tablet strength matched to your dog's current weight.
| Dog Weight Range | Tablet Strength (mg fluralaner) | Approximate mg/kg Dose | Dosing Interval |
|---|---|---|---|
| 5.1–11 lb (2.3–5 kg) | 112.5 mg | 25–50 mg/kg | Every 12 weeks |
| 11.1–22 lb (5–10 kg) | 250 mg | 25–50 mg/kg | Every 12 weeks |
| 22.1–44 lb (10–20 kg) | 500 mg | 25–50 mg/kg | Every 12 weeks |
| 44.1–88 lb (20–40 kg) | 1,000 mg | 25–50 mg/kg | Every 12 weeks |
| 88.1–123 lb (40–56 kg) | 1,400 mg | 25–35 mg/kg | Every 12 weeks |
For demodectic mange (off-label): Veterinarians typically prescribe a single oral dose at 25–56 mg/kg, with follow-up skin scrapings at 4 and 8 weeks to confirm mite elimination. Some cases may require a second dose.
Important administration note: Bravecto chewable tablets should be given with food or shortly after feeding. Studies show that fed administration significantly improves fluralaner absorption. The tablet can be given whole or broken and mixed with food — most dogs readily accept the flavored chewable.
Side Effects: What to Watch For
In pre-approval field studies and post-market surveillance, Bravecto has demonstrated a strong safety profile when used at labeled dosages. However, as with all isoxazoline-class drugs, side effects can occur. Understanding the frequency and severity helps you monitor your dog appropriately.
| Side Effect | Estimated Frequency | Severity | Action |
|---|---|---|---|
| Vomiting | 1.6–2.1% | Mild | Monitor; contact vet if persistent |
| Decreased appetite | 1.1–1.4% | Mild | Monitor; usually resolves within 24 hours |
| Diarrhea | 0.8–1.6% | Mild | Monitor hydration; call vet if >48 hours |
| Lethargy | 0.5–1.1% | Mild | Monitor; contact vet if lasts >24 hours |
| Flatulence | 0.3–0.5% | Mild | No intervention needed |
| Seizures / tremors | Rare (<0.1%) | Serious | Emergency vet visit immediately |
| Ataxia (uncoordinated movement) | Rare (<0.1%) | Serious | Emergency vet visit immediately |
| Muscle tremors | Rare (<0.1%) | Serious | Emergency vet visit immediately |
- Your dog experiences a seizure of any duration after taking Bravecto
- Uncontrollable muscle tremors or twitching develop
- Your dog cannot walk normally or appears severely uncoordinated
- Persistent vomiting (more than 3 episodes in 24 hours)
- Facial swelling, hives, or difficulty breathing (possible allergic reaction)
- Your dog becomes unresponsive or collapses
ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies)
Pet Poison Helpline: (855) 764-7661 (24/7)
The Isoxazoline and Seizure Connection
In September 2018, the FDA issued an advisory about the isoxazoline drug class (fluralaner, afoxolaner, sarolaner, lotilaner) and neurological adverse events including seizures, muscle tremors, and ataxia. This advisory was based on post-market adverse event reports. The FDA has not removed these products from the market, and they remain widely prescribed — but the advisory means veterinarians should use caution prescribing isoxazolines to dogs with a pre-existing history of seizures or neurological disorders.
If your dog has epilepsy, idiopathic seizures, or any neurological condition, discuss alternative flea and tick preventives with your veterinarian before starting Bravecto.
Contraindications: Dogs Who Should NOT Receive Bravecto
Bravecto is contraindicated or should be used with extreme caution in the following situations:
- Puppies under 6 months of age — Safety has not been established in puppies younger than 6 months
- Dogs under 5.1 lb (2.3 kg) — No appropriate dosage strength is available
- Dogs with a known seizure disorder — Including idiopathic epilepsy or a history of cluster seizures; the isoxazoline class may lower the seizure threshold
- Dogs with known hypersensitivity to fluralaner — Though rare, allergic reactions to the active ingredient preclude further use
Use with caution and veterinary monitoring in:
- Dogs with a history of neurological disease (vestibular disease, prior head trauma, brain tumors)
- Geriatric dogs with declining liver or kidney function — fluralaner is metabolized hepatically and excreted primarily in feces
- Brachycephalic breeds with pre-existing respiratory compromise — while not a direct contraindication, any systemic reaction could compound breathing difficulties
Regarding pregnancy and lactation: Bravecto has been evaluated for safety in breeding, pregnant, and lactating dogs. The FDA-approved label states it is safe for use in these populations, but your veterinarian should still make the final determination based on your dog's individual health status.
Drug Interactions and Concurrent Medications
| Medication / Substance | Interaction Risk | Recommendation |
|---|---|---|
| Phenobarbital (seizure medication) | Moderate — may reduce fluralaner efficacy through hepatic enzyme induction | Monitor parasite control; vet may adjust interval |
| Potassium bromide | Low — no direct interaction, but both affect neurological function | Use only under close veterinary supervision |
| Other isoxazolines (NexGard, Simparica) | High — duplicative mechanism, risk of overdose | Never combine isoxazoline products |
| NSAIDs (carprofen, meloxicam) | Low — no documented direct interaction | Generally safe to use concurrently; inform your vet |
| Heartworm preventives (ivermectin, milbemycin) | Low — different drug classes and mechanisms | Safe to use together; commonly co-prescribed |
| Corticosteroids (prednisone) | Low — no direct pharmacokinetic interaction | Safe concurrently; vet should manage overall protocol |
Critical rule: Never administer Bravecto alongside another isoxazoline-class drug (NexGard, Simparica, Credelio, or Bravecto Topical). Duplicate dosing can increase the risk of neurological side effects. If switching from one flea/tick preventive to Bravecto, wait until the previous product's dosing interval has fully elapsed.
How Long Does My Dog Need to Be on Bravecto?
The duration of Bravecto use depends on your geographic location, your dog's lifestyle, and the specific parasites your veterinarian is targeting.
Year-round prevention (most U.S. dogs): The American Veterinary Medical Association (AVMA) and the Companion Animal Parasite Council (CAPC) recommend year-round flea and tick prevention for most dogs in the United States. Fleas can survive indoors year-round, and many tick species remain active whenever temperatures exceed 40°F (4°C). For year-round protection, this means approximately four Bravecto doses per year (every 12 weeks).
Seasonal prevention (northern climates): In regions with sustained freezing temperatures and genuine tick dormancy (parts of Minnesota, North Dakota, northern Maine), some veterinarians may recommend seasonal protocols — typically March through November. This would mean approximately three doses per year.
For mange treatment (off-label): Demodectic mange is typically treated with a single dose, followed by recheck skin scrapings. Some refractory cases may require a second dose 8–12 weeks later.
Your veterinarian will tailor the prevention schedule to your dog's risk profile. Dogs who hike in tick-endemic areas, visit dog parks frequently, or live in multi-pet households with outdoor cats will typically need uninterrupted year-round coverage.
Monitoring, Missed Doses, and Overdose Protocol
Monitoring Requirements
Bravecto does not require routine blood work for parasite prevention use in healthy adult dogs. However, your veterinarian may recommend:
- Annual wellness exam — Confirm weight hasn't shifted into a different dosing bracket (common in growing puppies or weight-changing adults)
- Pre-treatment assessment — For dogs with a history of seizures, liver disease, or kidney disease, your vet may recommend baseline blood chemistry (ALT, BUN, creatinine) before starting isoxazolines
- Follow-up skin scrapings — If Bravecto is prescribed off-label for demodectic mange, expect rechecks at 4 and 8 weeks post-treatment
- Adverse event monitoring — Watch for GI signs within 48 hours of each dose and neurological signs throughout the 12-week interval
What to Do If You Miss a Dose
If you forget to give a scheduled Bravecto dose, administer it as soon as you remember and with food. Then resume the 12-week interval from that new date. For example, if the dose was due on January 1 but you administer it on January 15, the next dose is due April 9 (12 weeks from January 15).
During the gap between the missed dose and administration, your dog may have reduced parasite protection. Check your dog thoroughly for attached ticks and monitor for flea activity. If you live in a high-risk area for tick-borne diseases (Lyme disease, Ehrlichiosis, Anaplasmosis), mention the gap to your veterinarian at the next visit — they may recommend a tick-borne disease screening panel.
Overdose Protocol
In safety studies, dogs received fluralaner at up to 5× the maximum labeled dose without serious adverse events. However, accidental overdose (such as giving two tablets or using the wrong weight-class tablet) should still be treated seriously:
- Do not induce vomiting at home unless specifically instructed by a veterinarian or poison control
- Call your veterinarian or emergency vet immediately
- Contact ASPCA Animal Poison Control: (888) 426-4435 (a consultation fee of approximately $95 applies, but they provide expert toxicological guidance)
- Monitor for neurological signs — tremors, ataxia, seizures — especially in the first 4–6 hours after ingestion
- Bring the packaging to the vet visit so the exact mg ingested can be calculated
Cost, Availability, and Alternatives
As of 2026, Bravecto chewable tablets typically cost $45–$65 per dose at veterinary clinics, making the annual cost approximately $180–$260 per year (four doses). Pricing varies by region, clinic markup, and whether your veterinarian offers manufacturer rebates or multi-dose discounts.
Generic availability: As of 2026, fluralaner does not have widely available generic equivalents for the oral chewable formulation in the United States. Merck Animal Health holds patent protections. The topical formulation may have limited generic competition in some markets, but availability is inconsistent.
Where to purchase: Bravecto should be purchased directly from your veterinarian or through vet-verified online pharmacies (such as Chewy Pharmacy, Vetsource, or your clinic's online store). Purchasing from unauthorized sources risks counterfeit or improperly stored product — fluralaner tablets exposed to extreme temperatures may degrade in efficacy.
Bravecto vs. Alternatives: Quick Comparison
| Product | Active Ingredient | Interval | Est. Annual Cost | Heartworm Coverage? |
|---|---|---|---|---|
| Bravecto (oral) | Fluralaner | Every 12 weeks | $180–$260 | No |
| NexGard | Afoxolaner | Monthly | $180–$280 | No |
| Simparica Trio | Sarolaner + moxidectin + pyrantel | Monthly | $250–$360 | Yes |
| Credelio | Lotilaner | Monthly | $180–$260 | No |
| Seresto Collar | Imidacloprid + flumethrin | Every 8 months | $65–$90 | No |
| Vectra 3D (topical) | Dinotefuran + pyriproxyfen + permethrin | Monthly | $140–$200 | No |
For dogs who need combined flea/tick AND heartworm prevention, pairing Bravecto with a separate heartworm preventive (such as Heartgard Plus or Interceptor Plus) is a common strategy. Alternatively, Simparica Trio offers all-in-one monthly coverage but requires more frequent dosing. Your veterinarian can help you choose the protocol that best fits your dog's health profile, your compliance preferences, and your budget.
Frequently Asked Questions About Bravecto
Is Bravecto safe for all dogs?
Bravecto is safe for most dogs when used at the prescribed dosage under veterinary supervision. It is approved for dogs 6 months and older weighing at least 5.1 lb. However, dogs with a history of seizures or neurological disease should be evaluated carefully before starting any isoxazoline-class drug. Always disclose your dog's full medical history to your veterinarian.
Can I use Bravecto for cats?
Merck Animal Health has developed a Bravecto formulation specifically for cats (Bravecto Plus for Cats, which combines fluralaner with moxidectin). However, you should never administer a dog-formulated Bravecto product to a cat. Always use species-specific products prescribed by your veterinarian.
Does Bravecto protect against mosquitoes and heartworm?
No. Bravecto does not repel mosquitoes or prevent heartworm disease. If you live in a heartworm-endemic area (which includes most of the United States), your dog needs a separate heartworm preventive. Your veterinarian can recommend a compatible heartworm medication to use alongside Bravecto.
My dog threw up within an hour of taking Bravecto. Should I redose?
Call your veterinarian for guidance. If vomiting occurs within 1–2 hours of administration, a significant portion of the dose may not have been absorbed. Your vet will advise whether to redose immediately, wait and redose, or wait until the next scheduled interval. Do not redose without veterinary direction — administering a double dose increases the risk of adverse effects.
Can Bravecto be used with topical flea treatments?
Combining Bravecto with topical flea/tick products (Frontline, Advantix, etc.) is generally unnecessary and may increase the risk of adverse reactions without improving efficacy. If Bravecto alone is not providing adequate control, consult your veterinarian rather than layering products. In some cases, environmental flea treatment (home and yard) is more impactful than adding a second parasiticide.
Why does my dog still have fleas after starting Bravecto?
Flea infestations in the home environment can take 2–3 months to fully resolve, even with effective treatment on the dog. Adult fleas on your dog are only about 5% of the total flea population — the remaining 95% exists as eggs, larvae, and pupae in carpets, bedding, and furniture. Bravecto kills adult fleas that bite your dog, breaking the reproductive cycle, but you'll continue to see emerging fleas from the environment for several weeks. Consistent dosing plus thorough environmental cleaning (washing bedding in hot water, vacuuming daily, treating yard) will resolve the infestation.
Is there a withdrawal period if I want to switch from Bravecto to another product?
There is no medical withdrawal period required. However, you should wait until the current Bravecto dose's 12-week interval has elapsed before starting a new flea/tick preventive to avoid overlapping isoxazoline exposure. If switching to a non-isoxazoline product (like a topical or collar), timing is more flexible — but confirm the transition plan with your veterinarian.
Bottom line: Bravecto flea and tick for dogs offers one of the longest-lasting parasite protection intervals available by prescription, reducing the compliance burden of monthly treatments. Its safety profile is strong for most dogs, but the isoxazoline-class neurological advisory means your veterinarian should always be the one making the prescribing decision. Consult your veterinarian to determine whether Bravecto is the right parasite prevention choice for your dog's individual health needs, lifestyle, and risk profile.
Dr. Hannah Wickes
All our authors care for dogs every day — read more of their work on the authors page.
