Bravecto Canine: Complete Dosage, Safety & Side Effect Guide
Complete guide to Bravecto canine: dosage by weight, mechanism of action, side effects, drug interactions, cost, and alternatives for flea and tick prevention.
What Is Bravecto Canine Used For?
Bravecto is the brand name for fluralaner, a long-acting systemic parasiticide manufactured by Merck Animal Health. It is one of the most widely prescribed flea and tick preventives in veterinary medicine, favored for its extended duration of coverage compared to monthly alternatives.
FDA-approved veterinary uses for Bravecto canine include:
- Treatment and prevention of flea infestations (Ctenocephalides felis) for 12 weeks
- Treatment and control of four tick species for 8–12 weeks: American dog tick (Dermacentor variabilis), brown dog tick (Rhipicephalus sanguineus), lone star tick (Amblyomma americanum), and black-legged tick (Ixodes scapularis)
- Treatment and control of the Gulf Coast tick (Amblyomma maculatum) for 12 weeks
- Aid in the treatment and control of sarcoptic mange (Sarcoptes scabiei)
Common off-label (extra-label) uses that veterinarians may prescribe Bravecto for include:
- Demodectic mange (Demodex canis) — generalized demodicosis treatment
- Ear mite infestations (Otodectes cynotis)
- Adjunct therapy in flea allergy dermatitis (FAD) management programs
- Prevention of tick-borne disease transmission by reducing tick attachment duration
Off-label use is legal and common in veterinary medicine under the Animal Medicinal Drug Use Clarification Act (AMDUCA), but must be directed by your veterinarian based on clinical judgment.
How Does Bravecto Work in Dogs?
Mechanism of Action Explainer
Drug Class: Isoxazoline parasiticide
Active Ingredient: Fluralaner
How it works: Fluralaner belongs to the isoxazoline class of parasiticides, which act as GABA-gated chloride channel antagonists in arthropods (fleas, ticks, mites). When a parasite bites or feeds on a treated dog, fluralaner in the dog's blood and tissues binds to the parasite's GABA receptors, blocking chloride ion transfer across nerve membranes. This causes uncontrolled neuronal activity, leading to hyperexcitation, paralysis, and death of the parasite.
Key distinction: Isoxazolines target invertebrate GABA receptors with much higher selectivity than mammalian GABA receptors — this selectivity is what gives the drug its safety margin in dogs. However, the mechanism does involve neurological pathways, which is why neurological side effects (seizures) are a known, albeit uncommon, risk.
Onset of action: Bravecto begins killing fleas within 2 hours of administration, achieving >98% flea kill within 12 hours. Tick killing begins within 12 hours and reaches full efficacy within 48 hours.
Unlike topical parasiticides that work on the skin surface, Bravecto is absorbed systemically — it distributes into the dog's fat tissue and is slowly released over 12 weeks. This sustained-release mechanism is what allows for the extended dosing interval. Fluralaner has an exceptionally long half-life in dogs of approximately 12–15 days, and therapeutic blood levels persist for the full dosing interval.
Typical Bravecto Dosage by Dog Weight
Bravecto chewable tablets are dosed by weight band. Your veterinarian will prescribe the appropriate tablet strength based on your dog's current weight. The minimum effective dose is 25 mg/kg (11.4 mg/lb) of fluralaner per administration.
| Dog Weight Range | Tablet Strength (mg fluralaner) | Frequency | Duration of Protection |
|---|---|---|---|
| 4.4–9.9 lb (2–4.5 kg) | 112.5 mg | Every 12 weeks | Fleas: 12 weeks Ticks: 8 weeks |
| 10–22 lb (4.5–10 kg) | 250 mg | Every 12 weeks | Fleas: 12 weeks Ticks: 8 weeks |
| 22.1–44 lb (10–20 kg) | 500 mg | Every 12 weeks | Fleas: 12 weeks Ticks: 12 weeks |
| 44.1–88 lb (20–40 kg) | 1000 mg | Every 12 weeks | Fleas: 12 weeks Ticks: 12 weeks |
| 88.1–123.8 lb (40–56 kg) | 1400 mg | Every 12 weeks | Fleas: 12 weeks Ticks: 12 weeks |
Important administration instructions:
- Give with food. Bravecto chewables must be administered with or shortly after a meal. Fluralaner absorption is significantly reduced on an empty stomach — bioavailability drops by roughly 50% without food, which can compromise efficacy.
- Not for dogs under 4.4 lb (2 kg). The lowest tablet strength is not appropriate for very small dogs or puppies under the minimum weight.
- Minimum age: 6 months old.
- Whole tablet only. Tablets should not be broken or divided. If your dog falls between weight bands, your vet will determine the appropriate dosing strategy.
Bravecto Side Effects: What to Watch For
In pre-approval field studies and post-market surveillance data reviewed by the FDA Center for Veterinary Medicine, Bravecto demonstrated a favorable safety profile for the majority of dogs. However, as with any systemic parasiticide, side effects can occur.
Common Side Effects
| Side Effect | Reported Frequency | Typical Onset | Severity |
|---|---|---|---|
| Vomiting | ~1.4–2.0% | Within 24 hours | Mild |
| Decreased appetite | ~0.8–1.2% | Within 24–48 hours | Mild |
| Diarrhea | ~0.7–1.0% | Within 24–48 hours | Mild |
| Lethargy / drowsiness | ~0.5–0.8% | Within 24 hours | Mild |
| Increased thirst (polydipsia) | ~0.3–0.5% | Within 48 hours | Mild |
| Flatulence | <0.5% | Within 24 hours | Mild |
Most mild gastrointestinal side effects resolve within 24–48 hours without intervention. If vomiting occurs within 2 hours of dosing, contact your veterinarian — the tablet may not have been fully absorbed and redosing may be necessary.
Serious Side Effects Requiring Immediate Veterinary Attention
🚨 Call Your Veterinarian Immediately If You Observe:
- Seizures or tremors — The isoxazoline class carries a known risk of neurological adverse events. In 2018, the FDA issued guidance requiring updated labeling for all isoxazoline products noting the potential for muscle tremors, ataxia, and seizures, even in dogs without prior seizure history.
- Muscle tremors or uncoordinated movement (ataxia)
- Persistent vomiting — more than 2 episodes or lasting beyond 24 hours
- Severe lethargy — inability to stand, extreme weakness
- Facial swelling, hives, or difficulty breathing — signs of anaphylaxis (rare but requires emergency care)
ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies) if you suspect an adverse drug reaction or accidental overdose.
Pre-existing seizure disorder note: Bravecto should be used with caution in dogs with a history of seizures or epilepsy. Your veterinarian will weigh the risk-benefit ratio. Some veterinary neurologists recommend alternative flea/tick preventives (such as topical options outside the isoxazoline class) for dogs with poorly controlled seizure disorders.
Contraindications: Dogs Who Should NOT Receive Bravecto
Bravecto is contraindicated or requires careful veterinary risk assessment in the following situations:
- Puppies under 6 months of age — safety has not been established in puppies younger than 6 months.
- Dogs weighing less than 4.4 lb (2 kg) — no appropriate tablet strength exists for this weight class.
- Dogs with known hypersensitivity to fluralaner or any component of the tablet formulation.
- Dogs with a history of seizure disorders — not an absolute contraindication, but requires explicit veterinary risk-benefit evaluation. The FDA recommends caution.
- Collies and herding breeds with MDR1 gene mutation — while fluralaner has not been specifically implicated in MDR1-related adverse reactions (unlike ivermectin), some veterinary pharmacologists recommend extra caution. Discuss with your veterinarian if your dog has tested positive for the ABCB1/MDR1 mutation.
Breeding, pregnant, and lactating dogs: Bravecto has been evaluated in breeding, pregnant, and lactating dogs and was found to be safe for use in these populations at the labeled dose. However, your veterinarian should always be aware of your dog's reproductive status before prescribing.
Drug Interactions and Concurrent Medications
Fluralaner is metabolized primarily by hepatic pathways, and its long half-life means it persists in the system for weeks. The following interactions should be discussed with your veterinarian:
| Concurrent Medication | Interaction Risk | Clinical Significance |
|---|---|---|
| Other isoxazolines (NexGard, Simparica, Credelio) | Additive neurological risk | HIGH — Never combine two isoxazoline products. Risk of seizure and tremor increases significantly. |
| Phenobarbital / potassium bromide (anticonvulsants) | Potential reduced seizure threshold control | MODERATE — May lower seizure threshold in epileptic dogs. Vet monitoring required. |
| NSAIDs (carprofen, meloxicam, deracoxib) | No direct interaction documented | LOW — Generally safe to use concurrently. Both are commonly co-prescribed. |
| Heartworm preventives (ivermectin, milbemycin, moxidectin) | No direct interaction documented | LOW — Commonly prescribed together safely. Bravecto does NOT prevent heartworm — a separate preventive is needed. |
| Hepatically metabolized drugs (e.g., some antibiotics, antifungals) | Theoretical competition for liver enzyme pathways | LOW-MODERATE — Discuss with your vet if your dog is on long-term hepatically cleared medications. |
Always provide your veterinarian with a complete list of all medications, supplements, and over-the-counter products your dog is receiving before starting Bravecto.
Monitoring Requirements and Follow-Up
Monitoring Schedule
Healthy adult dogs on routine prevention:
- No routine blood work required specifically for Bravecto
- Annual wellness exam (standard preventive care) sufficient for monitoring
- Weigh your dog before each dose — if your dog crosses into a new weight band, the tablet strength may need adjustment
Dogs with seizure history or on concurrent anticonvulsants:
- Neurological assessment before starting Bravecto
- Follow-up within 2–4 weeks of first dose to assess tolerance
- Seizure log monitoring — document any seizure activity, frequency, and severity
- Consider therapeutic drug monitoring for concurrent anticonvulsants if seizure control changes
Dogs being treated off-label for demodicosis or sarcoptic mange:
- Skin scraping at 4-week intervals to assess mite clearance
- Typically requires 2–3 consecutive doses (24–36 weeks total) depending on severity
- Follow-up dermatology exam to confirm resolution
Bravecto does not require routine hepatic or renal panel monitoring in healthy dogs, unlike some other long-term medications. However, if your dog is on multiple medications or has pre-existing liver or kidney disease, your veterinarian may recommend periodic blood chemistry panels as part of overall health monitoring.
Missed Dose and Overdose Protocol
If You Miss a Scheduled Dose
Because Bravecto provides 12 weeks of protection, the window for a "late" dose is somewhat forgiving compared to monthly preventives:
- Within 1–2 weeks of the due date: Administer the missed dose immediately with food. Resume the normal 12-week schedule from the date you gave the late dose. Flea and tick protection may be slightly reduced during the gap but typically does not drop to zero.
- More than 2 weeks late: Administer immediately with food. Your dog may have been vulnerable to flea and tick infestation during the gap period. Inspect your dog thoroughly for ticks and signs of flea infestation (excessive scratching, flea dirt). Your veterinarian may recommend a fast-acting oral adulticide (such as Capstar/nitenpyram) for immediate flea knockdown while waiting for Bravecto to reach full efficacy.
- Do NOT double-dose. Never give two tablets to "catch up." This increases the risk of adverse effects without improving efficacy.
If an Overdose Occurs
In safety studies, dogs administered fluralaner at up to 5 times the maximum labeled dose (approximately 125 mg/kg) did not show serious adverse effects. However, individual sensitivity varies.
If your dog accidentally receives more than the prescribed dose:
- Monitor closely for 24–72 hours for vomiting, tremors, ataxia, or seizures
- Contact your veterinarian or the ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies) for guidance
- If neurological signs develop, seek emergency veterinary care immediately
- Bring the tablet packaging with you so the vet can determine the exact amount ingested
Bravecto Cost and Generic Availability
Bravecto pricing varies by tablet strength, veterinary clinic markup, and whether you purchase through your vet's office or an authorized online pharmacy.
| Tablet Strength | Dog Weight | Per Dose Cost | Annual Cost (4 doses) |
|---|---|---|---|
| 112.5 mg | 4.4–9.9 lb | $42–$52 | $168–$208 |
| 250 mg | 10–22 lb | $48–$58 | $192–$232 |
| 500 mg | 22.1–44 lb | $54–$65 | $216–$260 |
| 1000 mg | 44.1–88 lb | $60–$74 | $240–$296 |
| 1400 mg | 88.1–123.8 lb | $68–$82 | $272–$328 |
Generic availability: As of 2026, there is no FDA-approved generic equivalent of Bravecto chewable tablets for dogs in the United States. Merck Animal Health holds the marketing exclusivity. Some international markets may have fluralaner products under different brand names, but these are not interchangeable with U.S.-approved Bravecto and should not be purchased from unverified sources.
Cost-saving tips:
- Many veterinary clinics offer Bravecto as part of bundled wellness plans that include annual exams, vaccines, and heartworm testing at a reduced combined rate
- Authorized online pharmacies (VetRxDirect, Chewy Pharmacy, 1-800-PetMeds) may offer lower per-dose pricing with a valid prescription from your vet
- Merck Animal Health periodically offers manufacturer rebates — ask your veterinary clinic about current promotions
- Some pet insurance plans with wellness add-ons cover a portion of preventive medication costs
How Long Does My Dog Need to Be on Bravecto?
This depends entirely on your geographic location, lifestyle, and your veterinarian's recommendation:
- Year-round prevention (recommended for most U.S. dogs): The Companion Animal Parasite Council (CAPC) and most veterinary parasitologists recommend year-round flea and tick prevention for dogs in the United States. Fleas can survive indoors in climate-controlled homes during winter, and tick species like the brown dog tick remain active year-round in many regions.
- Seasonal use (limited regions): In some northern climates with reliably cold, prolonged winters, your veterinarian may recommend seasonal dosing (typically spring through late fall). This is becoming less common as climate patterns shift and tick ranges expand.
- Treatment courses for mange: Dogs being treated for sarcoptic or demodectic mange typically require 2–3 consecutive doses (spanning 24–36 weeks), with skin scrapings to confirm mite elimination before discontinuing.
For routine prevention, Bravecto is intended as a long-term, ongoing medication — there is no defined "course" to complete. You continue administering it as long as flea and tick exposure risk exists.
Alternatives to Bravecto
If Bravecto isn't the right fit for your dog — due to cost, side effect concerns, or medical contraindications — your veterinarian may recommend one of these alternatives:
| Product | Drug Class | Dosing Interval | Route | Key Difference from Bravecto |
|---|---|---|---|---|
| NexGard (afoxolaner) | Isoxazoline | Monthly | Oral chew | Same drug class, shorter duration — may suit dogs where shorter exposure window is preferred |
| Simparica Trio (sarolaner + moxidectin + pyrantel) | Isoxazoline + macrocyclic lactone + tetrahydropyrimidine | Monthly | Oral chew | Adds heartworm + intestinal parasite coverage in one chew |
| Credelio (lotilaner) | Isoxazoline | Monthly | Oral chew | Same class, monthly dosing, approved for puppies as young as 8 weeks |
| Frontline Plus (fipronil + (S)-methoprene) | Phenylpyrazole + insect growth regulator | Monthly | Topical | Non-isoxazoline — preferred option for dogs with seizure history; OTC available |
| Seresto collar (imidacloprid + flumethrin) | Neonicotinoid + pyrethroid | Every 8 months | Topical collar | Longest-lasting non-oral option; non-isoxazoline class |
Important note: Switching between flea and tick products should always be done under veterinary guidance. Timing the transition correctly — especially when switching from Bravecto's long-acting formulation to a monthly product — is critical to avoid gaps in protection or accidental overlapping doses of the same drug class.
Frequently Asked Questions About Bravecto
Is Bravecto safe for my dog?
For the vast majority of dogs, yes. Bravecto has been administered to millions of dogs worldwide since its FDA approval in 2014, and large-scale post-market surveillance supports its safety profile. The most common side effects are mild and self-limiting (vomiting, decreased appetite). The serious neurological side effects are uncommon but real — dogs with pre-existing seizure disorders require individualized risk assessment by a veterinarian. Always consult your veterinarian before starting any new medication.
Does Bravecto protect against heartworm?
No. Bravecto only targets fleas, ticks, and certain mites. It does not prevent heartworm disease. Your dog will need a separate heartworm preventive (such as Heartgard Plus, Interceptor Plus, or Revolution Plus). Some combination products like Simparica Trio include both an isoxazoline and a heartworm preventive in a single chew.
Can I give Bravecto to my cat?
No. Bravecto chewable tablets are formulated and approved only for dogs. Merck does manufacture a Bravecto topical solution approved for cats, but the canine oral formulation should never be given to cats. The dosing, absorption, and safety profile differ significantly between species.
My dog spit out the Bravecto tablet — what should I do?
If you see your dog spit out or vomit the tablet within 2 hours of administration, contact your veterinarian. The medication may not have been fully absorbed, and your vet may recommend redosing. If vomiting occurs after 2 hours, a meaningful portion of the drug has likely been absorbed — your vet will advise whether redosing is needed.
Can I buy Bravecto without a prescription?
No. Bravecto is a prescription-only medication in the United States. Any website offering Bravecto without requiring a valid veterinary prescription is operating outside FDA regulations and may be selling counterfeit, expired, or improperly stored product. Always obtain Bravecto through your veterinarian or an accredited online pharmacy that requires a prescription.
How should I store Bravecto tablets?
Store at or below 86°F (30°C) in the original packaging. Do not remove tablets from the blister pack until ready to administer. Keep out of reach of children and pets — the chewable formulation is palatable, and accidental ingestion of multiple tablets by a dog could result in overdose.
This guide is intended for educational purposes only and does not replace professional veterinary advice. Always consult your veterinarian before starting, stopping, or changing any medication regimen for your dog.
Anouk Beaumont
All our authors care for dogs every day — read more of their work on the authors page.
