Dog Flea Tablets Bravecto: Complete Prescription Guide for Owners
dog flea tablets Bravecto: dosage, side effects, safety data, cost, and how this 12-week prescription chewable protects your dog.
What Are Bravecto Dog Flea Tablets?
Bravecto is a chewable oral parasiticide manufactured by Merck Animal Health (known as MSD Animal Health outside North America). The active ingredient, fluralaner, belongs to the isoxazoline drug class — the same family that includes afoxolaner (NexGard), sarolaner (Simparica), and lotilaner (Credelio). What sets Bravecto apart from competitors is its extended duration of action: a single chewable tablet provides up to 12 weeks of flea and tick protection, compared to the 4-week cycle of most monthly oral preventives.
Bravecto chewables were first approved by the FDA in 2014 for dogs and have since become one of the most widely prescribed ectoparasite preventives in veterinary medicine. In 2022, Merck expanded the Bravecto line to include Bravecto 1-Month chewables (fluralaner, shorter-acting formulation) and Bravecto Plus (topical, combining fluralaner with moxidectin for heartworm and intestinal parasite coverage). This guide focuses specifically on the original Bravecto 12-week chewable tablets — the product most dog owners search for when researching "dog flea tablets Bravecto."
How Does Bravecto Work? Mechanism of Action Explained
Drug Class: Isoxazoline (GABA-gated chloride channel antagonist)
Target: Parasite nervous system — specifically ligand-gated chloride channels in arthropod nerve and muscle cells
Result: Uncontrolled neural hyperactivity → paralysis → death of fleas and ticks
Fluralaner works systemically. After your dog chews and swallows the tablet, the drug is absorbed through the gastrointestinal tract into the bloodstream. When a flea or tick bites your dog and ingests blood containing fluralaner, the compound binds to gamma-aminobutyric acid (GABA)-gated chloride channels in the parasite's nervous system. This binding is highly selective for invertebrate receptors — mammalian GABA receptors have a significantly different structure, which is why fluralaner has a wide safety margin in dogs.
The binding blocks chloride ion flow across nerve cell membranes, causing hyperexcitation of the parasite's nervous system. Fleas typically die within 8 hours of the first dose, and ticks are killed within 12 hours of attachment. Because the parasite must bite to receive the dose, you may occasionally see a tick attached briefly before it dies and detaches — this is normal and does not indicate treatment failure.
Fluralaner's extended half-life in canine tissue is what enables the 12-week dosing interval. The drug distributes primarily to fat tissue and is slowly released back into circulation, maintaining effective plasma concentrations for approximately 84 days. According to pharmacokinetic data published in Parasites & Vectors, fluralaner's elimination half-life in dogs is approximately 15 days, with therapeutic levels sustained well beyond that period.
FDA-Approved Uses and Common Off-Label Applications
FDA-Approved Indications for Bravecto Chewables (dogs ≥6 months, ≥4.4 lb):
- Kills adult fleas (Ctenocephalides felis) and prevents flea infestations for 12 weeks
- Kills the American dog tick (Dermacentor variabilis) for 12 weeks
- Kills the brown dog tick (Rhipicephalus sanguineus) for 12 weeks
- Kills the lone star tick (Amblyomma americanum) for 8 weeks (not the full 12)
- Kills the black-legged tick/deer tick (Ixodes scapularis) for 12 weeks
- Treatment and control of sarcoptic mange (Sarcoptes scabiei)
- Treatment and control of demodectic mange (Demodex canis)
Common Off-Label Uses: Veterinary dermatologists frequently prescribe Bravecto as part of multi-modal treatment protocols for canine scabies (sarcoptic mange), generalized demodicosis, and as an adjunct in managing flea allergy dermatitis (FAD). Some veterinary parasitologists also recommend fluralaner for off-label control of Phlebotomus sand flies in regions where leishmaniasis is endemic, though this application is more established in European veterinary practice.
Important note: Bravecto chewables do not protect against heartworm, intestinal parasites (roundworms, hookworms, whipworms, tapeworms), or mosquitoes. If you want broader parasite coverage, discuss combination protocols or Bravecto Plus (topical) with your veterinarian.
Bravecto Dosage Chart by Dog Weight
Your veterinarian will prescribe the correct chewable size based on your dog's current weight. Bravecto chewables come in five weight-specific strengths. The target dose is fluralaner 25-56 mg/kg (11.4-25.4 mg/lb) administered orally once every 12 weeks.
| Dog Weight | Chewable Strength | Fluralaner per Tablet | Dosing Interval |
|---|---|---|---|
| 4.4 – 9.9 lb (2 – 4.5 kg) | Bravecto 112.5 mg | 112.5 mg | Every 12 weeks |
| 10 – 20 lb (4.5 – 9 kg) | Bravecto 250 mg | 250 mg | Every 12 weeks |
| 20.1 – 40 lb (9 – 18 kg) | Bravecto 500 mg | 500 mg | Every 12 weeks |
| 40.1 – 88 lb (18 – 40 kg) | Bravecto 1000 mg | 1000 mg | Every 12 weeks |
| 88.1 – 123 lb (40 – 56 kg) | Bravecto 1400 mg | 1400 mg | Every 12 weeks |
For dogs over 123 lb (56 kg): Your veterinarian will prescribe a combination of two chewable tablets that together provide the appropriate mg/kg dose. For example, a 140 lb dog might receive one 1400 mg tablet plus one 500 mg tablet.
Mange treatment dosing: For sarcoptic and demodectic mange, the FDA-approved protocol uses the same weight-based chewable, but your veterinarian may recommend administering two doses spaced 4 weeks apart (rather than 12 weeks) for severe cases, followed by skin scraping to confirm parasite elimination. Always follow your vet's specific treatment timeline for mange — do not default to the standard 12-week interval without veterinary guidance.
How to Administer Bravecto: Step-by-Step
Bravecto chewables are flavored (beef/pork liver base) and most dogs accept them willingly as a treat. However, proper administration matters for optimal absorption:
- Give with food. Bravecto chewables should be administered at or around the time of feeding. Fluralaner absorption is significantly enhanced when given with a meal — studies show approximately 2.5x higher bioavailability when administered with food versus on an empty stomach.
- Ensure the full dose is consumed. Watch your dog chew and swallow the entire tablet. If your dog spits out a portion or vomits within 2 hours of administration, contact your veterinarian — a replacement dose may be needed.
- Do not split or crush tablets unless specifically instructed by your veterinarian. The chewables are formulated to deliver a precise dose per tablet.
- Mark your calendar. Set a reminder for 12 weeks (84 days) from the administration date. Many owners use phone reminders or write the next dose date on their calendar. A gap in coverage leaves your dog vulnerable to re-infestation.
Side Effects: What to Watch For
In FDA-reviewed pre-approval field studies involving over 600 dogs, Bravecto demonstrated a favorable safety profile. However, as with any systemic medication, side effects can occur. Understanding frequency and severity helps you distinguish normal post-dose reactions from situations requiring veterinary intervention.
| Side Effect | Reported Frequency | Severity | What to Do |
|---|---|---|---|
| Vomiting | 1.4% | Mild | Monitor; usually self-resolving within 24 hours |
| Decreased appetite | 1.1% | Mild | Offer food next meal; contact vet if persists >48 hrs |
| Diarrhea | 0.8% | Mild | Ensure hydration; contact vet if bloody or >48 hrs |
| Lethargy | 0.7% | Mild | Allow rest; contact vet if severe or prolonged |
| Flatulence | 0.5% | Mild | Self-resolving; no intervention needed |
| Excessive thirst (polydipsia) | Rare | Mild | Monitor water intake; report if extreme |
Serious Side Effects Requiring Immediate Veterinary Attention
The isoxazoline drug class carries an FDA-issued alert regarding potential neurological adverse events. While rare, the following symptoms warrant immediate veterinary contact:
🚨 Contact your veterinarian or emergency clinic immediately if your dog exhibits:
- Muscle tremors or uncontrolled shaking
- Ataxia (loss of coordination, stumbling, wobbliness)
- Seizures (generalized or focal)
- Loss of consciousness or collapse
- Severe, persistent vomiting (>3 episodes in 24 hours)
These neurological events have been reported in dogs both with and without pre-existing seizure disorders. The FDA notes that most affected dogs recovered with supportive care, but prompt veterinary evaluation is essential.
ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies) — call if you suspect an overdose or severe adverse reaction.
Contraindications and Drug Interactions
Who Should NOT Receive Bravecto
Bravecto chewables are contraindicated or require careful veterinary risk-benefit assessment in the following situations:
- Dogs under 6 months of age — Bravecto chewables are not approved for puppies younger than 6 months. For younger puppies, your veterinarian may recommend alternative flea/tick products approved for their age group.
- Dogs under 4.4 lb (2 kg) — The smallest chewable tablet (112.5 mg) is dosed for dogs starting at 4.4 lb. Dogs below this weight threshold cannot receive an accurate dose from available formulations.
- Dogs with a known history of seizures or epilepsy — The FDA has flagged isoxazolines as potentially lowering the seizure threshold. While many epileptic dogs tolerate Bravecto without issue under veterinary supervision, your vet may opt for a non-isoxazoline preventive (e.g., topical or collar-based) as a precaution.
- Dogs with known hypersensitivity to fluralaner — If your dog has previously had an allergic reaction to Bravecto or any isoxazoline product, do not re-administer.
Use with caution in: Breeding, pregnant, or lactating dogs. While field studies did not reveal reproductive toxicity at labeled doses, the product label states that safe use in breeding animals has not been comprehensively evaluated. Your veterinarian will weigh the benefit of parasite protection (especially important for pregnant dogs, as fleas transmit disease) against theoretical risk.
Drug Interaction Grid
| Concurrent Medication | Interaction Risk | Clinical Notes |
|---|---|---|
| Heartworm preventives (ivermectin, milbemycin, moxidectin, selamectin) | None known | Commonly co-prescribed; no dose adjustment needed. Field studies tested concurrent use with ivermectin at 10x label dose with no adverse interaction. |
| NSAIDs (carprofen, meloxicam, firocoxib) | None known | Widely used concurrently in practice. No pharmacokinetic interaction documented. |
| Phenobarbital / potassium bromide (anti-seizure) | Moderate concern | Hepatic enzyme inducers may alter fluralaner metabolism. Discuss with your vet — an alternative ectoparasiticide may be preferred for dogs on chronic seizure management. |
| Other isoxazolines (NexGard, Simparica, Credelio) | HIGH — Do not combine | Never administer two isoxazoline products concurrently. This constitutes a drug-class overdose and significantly increases neurological risk. |
| Steroids (prednisone, dexamethasone) | None known | No documented interaction. Commonly used together in mange treatment protocols. |
| Antibiotics (amoxicillin, cephalexin, enrofloxacin) | None known | Safe for concurrent use during infection treatment. |
Always provide your veterinarian with a complete list of every medication, supplement, and over-the-counter product your dog receives before starting Bravecto. This includes flea shampoos, topical sprays, and any herbal remedies — your vet needs the full picture to ensure safe prescribing.
Monitoring, Duration of Use, and Long-Term Safety
Recommended Monitoring Protocol:
- First 48 hours post-dose: Observe for vomiting, diarrhea, appetite changes, or neurological signs. Most mild side effects emerge within this window.
- Annual wellness exam: Your veterinarian should reassess the appropriateness of continued Bravecto use during your dog's yearly checkup, particularly if your dog has developed new health conditions (seizure disorder, liver disease) since the last prescription.
- No routine blood work required: Unlike some systemic medications, Bravecto does not require periodic hepatic or renal panel monitoring in healthy dogs. However, if your dog is on concurrent medications that do require blood monitoring, your vet will handle that separately.
- Mange treatment follow-up: If Bravecto is prescribed for sarcoptic or demodectic mange, expect follow-up skin scrapings at 4-week intervals to confirm parasite clearance before discontinuing treatment.
How Long Does My Dog Need to Be on Bravecto?
For flea and tick prevention, Bravecto is typically administered year-round in most of the United States. The Companion Animal Parasite Council (CAPC) recommends continuous, year-round parasite prevention regardless of season, as fleas survive indoors during winter and tick activity varies by species and climate. In practice, this means your dog receives one chewable every 12 weeks — approximately 4 to 5 doses per year.
For mange treatment, the duration depends on the type and severity. Sarcoptic mange typically requires 1-2 doses (spaced per your vet's protocol), while generalized demodicosis may require monthly dosing for 3-6 months alongside follow-up skin scrapings.
There is no maximum lifetime duration for Bravecto use in healthy dogs. Dogs have safely received consecutive 12-week doses for years in field studies and clinical practice without cumulative toxicity.
Cost Breakdown and Availability
Bravecto is available only through licensed veterinarians or verified online pharmacies that require a valid prescription (e.g., Chewy Pharmacy, 1-800-PetMeds with vet authorization). Pricing varies by weight class and purchasing channel:
| Weight Class | Vet Clinic Price (per chewable) | Online Pharmacy Price (per chewable) | Estimated Annual Cost (4-5 doses) |
|---|---|---|---|
| 4.4 – 9.9 lb | $45 – $55 | $40 – $50 | $160 – $250 |
| 10 – 20 lb | $48 – $60 | $42 – $55 | $168 – $275 |
| 20.1 – 40 lb | $52 – $65 | $45 – $58 | $180 – $290 |
| 40.1 – 88 lb | $58 – $72 | $50 – $65 | $200 – $325 |
| 88.1 – 123 lb | $65 – $80 | $55 – $72 | $220 – $360 |
Cost per month comparison: Because Bravecto lasts 12 weeks, the effective monthly cost ranges from approximately $13 – $22/month depending on your dog's weight — comparable to or slightly less than monthly oral preventives like NexGard ($18-$28/month) or Simparica ($17-$25/month) when calculated on an annualized basis.
Generic availability: As of 2026, there is no FDA-approved generic equivalent of fluralaner chewable tablets for dogs. Merck Animal Health holds the patent. Be wary of any online retailer claiming to sell "generic Bravecto" — these are likely counterfeit or unapproved products that may contain incorrect doses or harmful ingredients. Always verify that your online pharmacy is Vet-VIPPS accredited.
What to Do If You Miss a Dose or Suspect Overdose
Missed Dose Protocol
If you forget to administer your dog's scheduled Bravecto dose or realize the 12-week interval has lapsed:
- Administer the missed dose as soon as you remember. Do not wait for the next scheduled date.
- Reset the 12-week clock from the date you actually administered the late dose (not from the original due date).
- Do not double-dose. Never give two tablets to "catch up" — this increases the risk of adverse effects without improving efficacy.
- Inspect your dog for parasites. If the gap in coverage exceeded 2-3 weeks beyond the 12-week interval, your dog may have been exposed. Check for fleas (flea dirt, scratching) and ticks (embedded arthropods) and inform your veterinarian.
Overdose Response
If your dog accidentally ingests more than the prescribed dose (e.g., got into the medicine cabinet, received a duplicate dose by a family member who didn't realize it was already given):
- Call your veterinarian or emergency veterinary clinic immediately.
- Contact ASPCA Animal Poison Control: (888) 426-4435 (24/7, consultation fee applies).
- Monitor for neurological signs: tremors, ataxia, seizures, excessive salivation, or vomiting.
- Do not induce vomiting unless specifically instructed by a veterinarian or poison control specialist.
- Have the packaging available to report the exact product strength and estimated quantity ingested.
In safety studies, dogs administered fluralaner at up to 5x the upper label dose (at 8-week intervals for 6 treatments) showed no serious adverse effects, suggesting a wide therapeutic index. However, individual sensitivity varies, and veterinary guidance is always warranted after any overdose event.
Bravecto vs. Alternatives: How Does It Compare?
If Bravecto isn't the right fit for your dog — whether due to seizure history, weight restrictions, or personal preference — your veterinarian may recommend one of these alternatives:
| Product | Active Ingredient | Duration | Route | Key Difference |
|---|---|---|---|---|
| Bravecto 12-Week | Fluralaner | 12 weeks | Oral chew | Longest-lasting oral isoxazoline |
| NexGard | Afoxolaner | 4 weeks | Oral chew | Monthly; approved for puppies ≥8 weeks |
| Simparica | Sarolaner | 5 weeks (35 days) | Oral chew | Slightly extended monthly interval |
| Credelio | Lotilaner | 4 weeks | Oral chew | Must be given with food; fast tick kill |
| Seresto Collar | Imidacloprid + flumethrin | 8 months | Topical collar | Non-isoxazoline; good for seizure-prone dogs |
| Frontline Plus | Fipronil + (S)-methoprene | 4 weeks | Topical spot-on | Non-systemic; non-isoxazoline class |
Choosing between options depends on: your dog's age, weight, seizure history, your ability to remember monthly vs. quarterly dosing, whether your dog tolerates oral medications, and your veterinarian's assessment of regional parasite pressure. There is no universally "best" product — the right choice is the one your veterinarian recommends for your individual dog's health profile.
Frequently Asked Questions
Is Bravecto safe for all dog breeds?
Bravecto has been tested and approved for use across all dog breeds, including breeds with the MDR1 gene mutation (e.g., Collies, Australian Shepherds, German Shepherds). Field studies included dogs of various breeds with no breed-specific adverse event patterns. However, the isoxazoline class carries a precaution for dogs with seizure histories regardless of breed. Always discuss your dog's specific breed-related health risks with your veterinarian.
Can I use Bravecto on my cat?
No. Bravecto chewable tablets are formulated and approved for dogs only. Merck does manufacture a Bravecto topical solution approved for cats, but the canine oral chewable must never be given to cats. The dosage, formulation, and safety profile are species-specific.
My dog vomited after taking Bravecto — do I need to give another dose?
If vomiting occurs within 2 hours of administration, a significant portion of the dose may not have been absorbed. Contact your veterinarian — they will typically recommend re-dosing with a new chewable. If vomiting occurs more than 2 hours after administration, the drug is likely already absorbed and re-dosing is usually not necessary, but confirm with your vet.
Does Bravecto kill ticks that are already on my dog?
Yes. Bravecto kills existing tick infestations within 12 hours of administration. However, because the tick must bite and ingest blood containing fluralaner to receive the lethal dose, you may see ticks still attached during that 12-hour window. Dead ticks will detach naturally. Check your dog thoroughly 24 hours post-dose and remove any remaining dead ticks with tweezers.
Can I bathe my dog after giving Bravecto?
Yes. Because Bravecto chewables work systemically (through the bloodstream, not on the skin surface), bathing, swimming, and rain exposure do not reduce efficacy. This is a key advantage over topical spot-on products, which typically require 48 hours of dry time after application. You can bathe your dog the same day as administering a Bravecto chewable.
How quickly does Bravecto start working?
Bravecto begins killing fleas within 2 hours of administration and achieves >98% flea kill within 12 hours. Ticks are killed within 12 hours of attachment throughout the 12-week dosing period. For the lone star tick specifically, efficacy duration is 8 weeks rather than the full 12.
Is there a Bravecto product that also covers heartworm?
Bravecto Plus (topical solution) combines fluralaner with moxidectin and covers heartworm, fleas, ticks, roundworms, hookworms, and ear mites. However, Bravecto Plus is a topical application — not a chewable tablet — and is currently approved for cats. For dogs, Merck has not released an oral Bravecto combination that includes heartworm prevention as of 2026. Most veterinarians pair Bravecto chewables with a separate heartworm preventive (e.g., Heartgard Plus, Interceptor Plus, or Revolution).
This article is for informational purposes only and does not replace professional veterinary advice. Always consult your veterinarian for diagnosis, treatment, and medication decisions specific to your dog's health. Product availability, pricing, and labeling may vary by region and change over time. References: FDA Center for Veterinary Medicine, Merck Animal Health, and the Merck Veterinary Manual.
Priya Sutaria
All our authors care for dogs every day — read more of their work on the authors page.
