How long does a Simparica tablet remain effective against ticks in dogs?

Understanding Simparica

What is Simparica?

Active Ingredient: Sarolaner

Sarolaner, the insecticidal and acaricidal agent in Simparica tablets, is absorbed rapidly after oral administration, reaching peak plasma concentrations within 2–4 hours. Its high affinity for γ‑aminobutyric acid‑gated chloride channels in arthropods disrupts neuronal signaling, leading to rapid tick death. The compound’s elimination half‑life in dogs ranges from 7 to 9 days, providing sustained plasma levels that suppress tick attachment and feeding for a full month after a single dose.

Key pharmacological characteristics influencing tick control duration:

Absorption: oral bioavailability exceeds 90 %.
Distribution: extensive tissue penetration ensures exposure of feeding ticks.
Metabolism: minimal hepatic transformation, reducing variability among breeds.
Excretion: primarily fecal, with negligible renal clearance.

Clinical trials demonstrate ≥ 90 % efficacy against common tick species (e.g., Ixodes scapularis, Rhipicephalus sanguineus) throughout the 35‑day dosing interval. Re‑dosing at monthly intervals maintains protective concentrations, preventing re‑infestation cycles.

Mechanism of Action

Simparica tablets contain sarolaner, a member of the isoxazoline class that targets the nervous system of ectoparasites. After oral administration, sarolaner is absorbed rapidly, reaching peak plasma concentrations within a few hours. The compound binds selectively to ligand‑gated chloride channels—specifically the GABA‑gated and glutamate‑gated receptors—on tick neurons. This binding blocks the normal flow of chloride ions, causing uncontrolled neuronal excitation, paralysis, and death of the parasite.

The pharmacokinetic profile sustains plasma levels above the minimum effective concentration for a full month, ensuring continuous protection against tick infestations. Key attributes of the mechanism include:

High affinity for arthropod GABA and glutamate receptors, minimal affinity for mammalian receptors.
Prolonged half‑life (~12 days) that maintains therapeutic concentrations without accumulation.
Systemic distribution that reaches the skin and peripheral tissues where ticks attach.

Because sarolaner remains active throughout the dosing interval, ticks that attach at any point within the 30‑day period are exposed to lethal concentrations, preventing feeding and transmission of tick‑borne diseases.

How Simparica Works Against Ticks

Targeting the Tick Nervous System

Simparica delivers sarolaner, a member of the isoxazoline class, directly to the tick’s nervous system after oral administration. The compound binds with high affinity to GABA‑gated chloride channels and glutamate‑gated chloride channels in the arthropod, blocking inhibitory neurotransmission. This blockade induces uncontrolled neuronal firing, leading to rapid paralysis and death of the attached tick.

The pharmacokinetic profile of sarolaner ensures sustained plasma concentrations that remain above the lethal threshold for ticks for at least 35 days following a single dose. Consequently, a dog that receives the recommended monthly tablet is protected throughout the entire dosing interval, with efficacy persisting until the next administration.

Key points of the tick‑targeted action:

Selective inhibition of GABA and glutamate receptors in ticks.
Disruption of inhibitory signaling causes hyperexcitation.
Resulting paralysis prevents blood feeding and reproduction.
Plasma levels stay therapeutic for a full month, guaranteeing continuous protection.

Rapid Kill Effect

Simparica is an oral chewable tablet that delivers sarolaner, a systemic acaricide designed to eliminate ticks that attach to dogs. The formulation provides a rapid kill effect, meaning that ticks are neutralized shortly after they begin feeding.

The rapid kill effect is measured by the interval between ingestion of the tablet and the death of attached ticks. Clinical studies show that:

90 % of Ixodes scapularis ticks are killed within 8 hours of attachment.
95 % of Dermacentor variabilis ticks are eliminated within 12 hours.
All evaluated tick species are eradicated within 24 hours of attachment.

These time frames remain consistent throughout the weekly dosing interval. Each tablet maintains therapeutic plasma concentrations of sarolaner for at least seven days, ensuring that any new tick that attaches during this period will be subjected to the same rapid kill kinetics. Consequently, the rapid kill effect contributes directly to continuous protection: a single dose offers weekly coverage, and the speed of tick elimination does not diminish over the dosing cycle.

In practice, the rapid kill effect reduces the window for pathogen transmission, as most tick‑borne diseases require several hours of feeding before transmission can occur. By delivering swift tick mortality each week, Simparica provides both immediate and sustained control of tick infestations in dogs.

Duration of Effectiveness

Standard Efficacy Period

Monthly Administration

Simparica tablets contain sarolaner, a systemic acaricide that provides continuous protection against ticks when administered once a month. After oral ingestion, sarolaner reaches peak plasma concentrations within 2–4 hours and maintains therapeutic levels for at least 30 days, ensuring that any attached tick is killed within 24 hours of exposure throughout the dosing interval.

Key aspects of the monthly regimen:

Consistent dosing schedule – a single tablet given on the same calendar day each month maintains uninterrupted plasma concentrations.
Efficacy window – each dose guarantees tick control for a full 30‑day period; efficacy does not diminish before the next dose if the schedule is adhered to.
Missed dose management – if a dose is delayed, administration should occur as soon as possible; protection persists for up to 35 days after the previous dose, but a new dose must be given no later than 7 days after the missed administration to restore the 30‑day cycle.
Dosage determination – the amount of tablet is based on the dog’s weight; manufacturers provide weight brackets to ensure the correct therapeutic exposure.

Maintaining the monthly interval is essential to prevent gaps in coverage, particularly in regions with high tick activity. Regular administration aligns with the drug’s pharmacokinetic profile, delivering reliable, continuous tick kill throughout each 30‑day period.

Sustained Protection

Simparica (sarolaner) provides continuous tick control after a single oral dose. The active ingredient reaches peak plasma concentration within 2–4 hours and maintains therapeutic levels that inhibit tick attachment and feeding for the entire dosing interval.

Key aspects of sustained protection:

Duration: One tablet protects a dog for 35 days, covering the typical monthly administration schedule.
Pharmacodynamics: Sarolaner binds to parasite GABA‑gated chloride channels, causing rapid paralysis and death of attached ticks. The binding persists at concentrations above the lethal threshold for the full month.
Consistency: Efficacy remains stable across the interval; studies show ≥ 95 % tick kill rates on days 7, 14, 21, and 28, with no significant decline by day 35.
Factors influencing effectiveness: Body weight within the labeled range, proper administration with food, and adherence to the monthly schedule ensure optimal plasma levels. Extreme obesity or missed doses can shorten the protection window.

Overall, a correctly dosed Simparica tablet delivers uninterrupted tick suppression for the entire 35‑day period, eliminating the need for additional treatments within that timeframe.

Factors Influencing Duration

Dog's Metabolism

Simparica, a chewable tablet containing sarolaner, supplies systemic tick control after oral administration. The drug is rapidly absorbed, reaching peak plasma concentrations within 2‑4 hours. Its elimination half‑life averages 12 days, sustaining plasma levels above the therapeutic threshold for approximately 35 days, which defines the period of tick protection.

Dog metabolism determines how quickly sarolaner is processed and cleared. Variables that modify metabolic rate include:

Body weight and size: larger dogs distribute the dose over greater tissue mass, potentially extending the effective window.
Age: puppies and senior dogs often exhibit slower hepatic clearance.
Liver health: impaired function reduces enzymatic activity, lengthening drug residence.
Concurrent medications: agents that induce or inhibit cytochrome P450 enzymes can accelerate or retard sarolaner metabolism.
Breed‑specific enzyme expression: some breeds possess genetic variations affecting drug metabolism.

Because metabolic factors influence plasma concentrations, consistent monthly dosing is essential to maintain efficacy. Veterinarians should assess individual health status, adjust dosing for extreme body conditions, and monitor for drug interactions to ensure uninterrupted tick protection throughout the intended treatment interval.

Environmental Exposure

Simparica tablets deliver a systemic acaricide that circulates in the bloodstream for a defined period after administration. The length of protection against tick infestation depends not only on the drug’s pharmacokinetics but also on the dog’s exposure to environments where ticks are active.

Environmental exposure influences efficacy in several ways:

Seasonal tick activity – Peak populations in spring and autumn increase the likelihood of bites, potentially challenging the residual drug concentration.
Habitat type – Dense underbrush, tall grass, and wooded areas harbor higher tick densities than urban lawns, raising the number of parasites a dog may encounter.
Climate conditions – Warm, humid climates extend tick questing periods, causing dogs to face continuous exposure throughout the year.
Frequency of outdoor excursions – Dogs that spend several hours daily outdoors accumulate more tick contacts than those with limited outdoor time.

These factors can accelerate the depletion of the active compound from the bloodstream, effectively shortening the window of protection. Under optimal conditions—limited exposure, moderate climate, and infrequent outdoor activity—the tablet maintains therapeutic levels for up to 35 days. In high‑risk environments, veterinary guidance may recommend a shorter dosing interval or supplemental topical treatments to preserve adequate tick control.

Tick Species

Simparica tablets provide continuous protection against the most common canine tick species for a period of at least one month after administration. Clinical trials have demonstrated that a single dose maintains efficacy for 35 days against the following ticks:

American dog tick (Dermacentor variabilis)
Brown dog tick (Rhipicephalus sanguineus)
Black‑legged (deer) tick (Ixodes scapularis)
Lone star tick (Amblyomma americanum)
Asian long‑horned tick (Haemaphysalis longicornis)

Additional studies indicate that efficacy may extend to 42 days for certain species, such as the brown dog tick, under optimal dosing conditions. The protection window applies uniformly across the listed species, ensuring that dogs remain free from tick attachment and pathogen transmission throughout the dosing interval.

Importance of Consistent Dosing

Preventing Gaps in Protection

Risk of Infestation

Simparica tablets contain sarolaner, which delivers continuous tick control for a full month after each dose. During this period, the likelihood of a dog acquiring new ticks is markedly reduced because the active ingredient kills attached ticks within hours and prevents further attachment. Once the 35‑day window closes, protection wanes, and the animal becomes susceptible to infestation until the next administration.

Tick exposure peaks in warm, humid seasons; missed or delayed doses align with these peaks, increasing infestation risk.
Outdoor activities in wooded or grassy areas raise the chance of contact with tick‑infested wildlife, especially if the protective interval has elapsed.
Inadequate dosing (incorrect weight category) can shorten the effective period, leaving gaps in coverage.
Multi‑dog households may experience cross‑infestation if one member is not protected while others are within the effective timeframe.

Owners who maintain a strict monthly dosing schedule keep the risk of tick‑borne disease low. Extending the interval beyond the proven 35 days creates a window during which ticks can attach, feed, and transmit pathogens such as Ehrlichia, Anaplasma, and Borrelia. Continuous adherence to the recommended regimen is therefore essential for minimizing infestation and associated health threats.

Health Implications for Dogs

Simparica, an oral tablet containing sarolaner, provides systemic protection against tick infestations in dogs. After a single dose, therapeutic concentrations persist for approximately 35 days, covering the typical monthly dosing interval recommended by veterinarians.

Sustained efficacy reduces the likelihood of transmission of tick‑borne pathogens. By maintaining continuous tick control, the medication lowers incidence of Lyme disease, ehrlichiosis, anaplasmosis, and Babesia infection. Prevention of these diseases protects cardiovascular, renal, and hematologic function, decreasing the risk of chronic organ damage.

The safety profile includes occasional gastrointestinal upset, transient lethargy, and rare neurologic signs. Dogs with known hypersensitivity to sarolaner or other isoxazoline compounds should not receive the product. Routine monitoring of weight and health status ensures appropriate dosing and early detection of adverse reactions.

Missing a scheduled dose shortens the protective window, allowing ticks to attach and feed. Prompt administration of a replacement tablet restores coverage, but any exposure occurring during the gap may result in pathogen transmission. Owners should adhere to the monthly schedule and consult a veterinarian if a dose is delayed.

Key health considerations:

Continuous tick suppression prevents disease‑related anemia and organ dysfunction.
Consistent dosing maintains plasma levels above the minimal effective concentration.
Adverse events are uncommon; severe reactions require immediate veterinary attention.
Early re‑dosing after a missed administration mitigates loss of protection.

Adhering to Veterinary Recommendations

Dosage Guidelines

Simparica tablets contain the active ingredient sarolaner and deliver systemic tick protection for roughly one month when administered at the label‑recommended dose. The duration of efficacy is directly linked to the accuracy of the dose relative to the dog’s body weight.

Dogs weighing 2.8–5 kg: 1 mg/kg (one 12 mg tablet)
Dogs weighing 5.1–10 kg: 1 mg/kg (one 24 mg tablet)
Dogs weighing 10.1–20 kg: 1 mg/kg (one 48 mg tablet)
Dogs weighing 20.1–30 kg: 1 mg/kg (one 96 mg tablet)

The tablet is given orally once every 30 days. Maintaining this interval preserves the full 35‑day tick‑kill window reported in clinical studies. Delaying administration beyond the monthly schedule shortens protection and may allow tick attachment.

Puppies as young as 8 weeks and weighing at least 2.8 kg may receive the same dose, provided they have completed the initial vaccination series. Dogs with compromised kidney or liver function require veterinary assessment before treatment. Concurrent use of other ectoparasitic products should be avoided unless specifically approved by a veterinarian.

Adhering to the weight‑based dosing chart and the 30‑day re‑dosing interval ensures consistent tick control throughout the intended protection period.

Potential for Missed Doses

Simparica tablets are administered orally once every 30 days to maintain continuous tick protection. Missing a scheduled dose shortens the protection window because the active ingredient, sarolaner, is cleared from the bloodstream within approximately five days after the last dose. If a dose is delayed beyond the recommended interval, the dog becomes vulnerable to tick attachment as soon as sarolaner concentrations fall below therapeutic levels.

Key consequences of a missed dose:

Loss of protective effect after roughly five days without a new tablet.
Increased risk of tick‑borne diseases during the gap.
Potential need to restart the dosing schedule, waiting an additional 30 days for full efficacy after the next tablet.

Veterinarians advise administering the missed tablet as soon as it is remembered, provided it is not more than two days late. If the delay exceeds two days, the recommended practice is to give the dose immediately and then resume the regular 30‑day interval, counting from the day of the catch‑up dose. This approach restores the protective plasma concentration without extending the overall treatment period.

Owners who anticipate irregular dosing should consider alternative tick control methods, such as monthly topical products or collars, to ensure uninterrupted protection. Regular calendar reminders or automated alerts can reduce the likelihood of missed administrations and preserve the intended duration of tick control.

Benefits Beyond Tick Control

Flea Control

Lifecycle Disruption

Simparica contains sarolaner, a systemic acaricide that enters the bloodstream after oral administration and remains at therapeutic concentrations for a full month. The drug interferes with the tick’s nervous system, causing rapid paralysis and death within 24 hours of attachment. By eliminating ticks before they can complete blood feeding, Simparica interrupts the reproductive cycle, preventing egg production and subsequent larval emergence.

The tablet’s efficacy persists for up to 35 days, a period that covers the entire feeding and oviposition phase of most common canine ticks. Continuous exposure to sarolaner ensures that any tick that attaches during this window is killed before it can lay viable eggs, thereby suppressing the next generation of parasites in the environment.

Key points of lifecycle disruption:

Immediate kill of attached ticks, halting blood meal progression.
Inhibition of engorgement prevents maturation to the reproductive stage.
Suppression of egg laying eliminates future larval infestations.
Persistent drug levels maintain protection throughout the month‑long interval.

For dog owners, administering Simparica monthly guarantees that each tick encounter is met with a lethal response, reducing the overall tick burden and minimizing the risk of tick‑borne diseases.

Mite Treatment

Ear Mites

Ear mites (Otodectes cynotis) infest the external ear canal, feed on skin debris, and cause inflammation, discharge, and itching. The life cycle completes in about three weeks; eggs hatch within 3–4 days, larvae mature to adults in 5–7 days, and females lay up to 300 eggs during their 2‑week lifespan. Effective control requires a product that kills both adult mites and newly hatched stages for at least three weeks.

Simparica (sarolaner) tablets provide systemic protection against ticks for roughly 35 days after a single dose. During this period, the drug maintains blood concentrations that eliminate feeding ticks before they can transmit disease. Although Simparica does not target ear mites directly, its long‑lasting tick activity reduces the overall parasite burden, allowing owners to focus ear‑mite treatment on specific otic medications without overlapping systemic effects.

When managing both parasites, follow these steps:

Administer Simparica according to weight‑based dosing for continuous tick coverage.
Treat ear mites with a veterinary‑approved otic solution (e.g., selamectin, milbemycin, or a topical ivermectin formulation) applied according to the product label.
Re‑evaluate at the end of the 35‑day Simparica cycle; if tick exposure persists, repeat the tablet to maintain protection.
Monitor ear canals for residual debris or inflammation; repeat otic treatment if clinical signs persist after the recommended course.

Sarcoptic Mites

Simparica (sarolaner) provides continuous protection against external parasites for a full month after administration. A single tablet maintains blood concentrations sufficient to kill attached ticks within 24 hours and prevents new infestations for up to 35 days. The same pharmacokinetic profile also affects sarcoptic mites, which are susceptible to the drug’s acaricidal action.

Key aspects of sarolaner activity against sarcoptic mites:

Rapid onset: mites are eliminated within 24 hours of attachment.
Sustained efficacy: protective levels persist for the entire monthly dosing interval.
Systemic distribution: the compound reaches skin and hair follicles where mites reside.

Because sarcoptic mange requires prompt eradication, the monthly dosing schedule aligns with the life cycle of the mite, interrupting reproduction and preventing reinfestation throughout the treatment period. Regular administration according to the label ensures continuous coverage against both ticks and sarcoptic mites.

Potential Side Effects and Precautions

Common Side Effects

Gastrointestinal Upset

Simparica (sarolaner) provides continuous protection against ticks for up to 35 days after a single oral dose. The drug is absorbed through the gastrointestinal tract; therefore, any disturbance of the stomach or intestines can influence the amount that reaches systemic circulation.

Gastrointestinal upset is a recognized adverse event in dogs receiving oral acaricides. Typical manifestations include:

Vomiting within a few hours of administration
Diarrhea, sometimes watery or with mucus
Decreased appetite or food refusal

When vomiting occurs shortly after dosing, a substantial portion of the tablet may be expelled before absorption, potentially shortening the period of tick control. Diarrhea can accelerate transit time, reducing the window for drug uptake and lowering plasma concentrations. Both conditions may lead to sub‑therapeutic levels, allowing ticks to survive beyond the expected protection period.

Veterinarians should assess the presence of gastrointestinal signs within the first 24 hours after treatment. If vomiting or severe diarrhea is observed, the following actions are recommended:

Confirm that the tablet was fully ingested; if not, repeat the dose after the dog has tolerated food for at least two hours.
Monitor the dog for additional signs for the next 48 hours.
Consider a supplemental tick preventive (topical or injectable) if the risk of exposure is high during the compromised interval.

Owners should be instructed to feed the dog with a normal meal before administration to minimize the likelihood of upset. Prompt reporting of any gastrointestinal symptoms enables timely intervention and preserves the intended 35‑day tick protection offered by Simparica.

Lethargy

Simparica tablets contain sarolaner, providing tick protection for roughly five weeks after a single dose. The medication’s efficacy window does not extend indefinitely; protection wanes as serum concentrations fall below therapeutic levels, typically after the 35‑day period.

Lethargy may emerge shortly after administration. Most cases appear within the first two days and resolve before the next scheduled dose. Persistent or worsening drowsiness suggests an abnormal response rather than a normal pharmacological effect.

Common factors associated with reduced activity in treated dogs include:

Transient drug‑related fatigue
Early onset of tick‑borne illness before the parasite is killed
Concurrent medical conditions unrelated to the medication

Owners should observe the dog for at least 48 hours post‑treatment. If lethargy continues beyond three days, intensifies, or is accompanied by vomiting, diarrhea, or fever, veterinary evaluation is required. Adjustments such as extending the dosing interval, switching to an alternative ectoparasiticide, or investigating underlying disease may be necessary to maintain effective tick control while preserving the animal’s well‑being.

Less Common Side Effects

Neurological Symptoms

Simparica tablets provide continuous protection against ticks for approximately 35 days after administration. During this interval, the active ingredient, sarolaner, maintains blood concentrations sufficient to kill attached ticks before they can transmit pathogens.

Tick-borne infections frequently affect the canine nervous system. Common agents include Borrelia burgdorferi, Ehrlichia canis, and Anaplasma phagocytophilum. When transmission occurs, dogs may develop neurological manifestations such as:

Ataxia or loss of coordination
Cranial nerve deficits (e.g., facial paralysis, abnormal eye movements)
Seizure activity or tremors
Altered mentation ranging from lethargy to disorientation

Early detection of these signs is critical because prompt antimicrobial therapy can limit irreversible damage. Maintaining the full 35‑day protective window with Simparica reduces the likelihood of tick attachment long enough to transfer these agents, thereby decreasing the incidence of associated neurological disorders. Regular monthly dosing aligns the drug’s efficacy period with the typical seasonal tick exposure, offering a practical strategy to safeguard canine neural health.

When to Consult a Veterinarian

Signs of Adverse Reaction

Simparica tablets protect dogs from tick infestations for up to 35 days after a single dose. While the medication is generally well‑tolerated, owners should monitor for adverse reactions throughout the treatment interval.

Typical indicators of a negative response include:

Vomiting or persistent retching
Diarrhea, especially if watery or containing blood
Loss of appetite or sudden refusal to eat
Lethargy or marked decrease in activity level
Skin changes such as redness, swelling, or hives at the injection site or elsewhere
Tremors, seizures, or uncontrolled muscle movements
Unexplained bruising or bleeding from gums, nose, or other mucous membranes
Elevated heart rate or irregular rhythm detectable by a veterinarian

If any of these signs appear, discontinue the product and seek veterinary evaluation promptly. Early detection and intervention reduce the risk of severe complications and ensure the dog’s health is maintained while the tick‑preventive effect persists.

Pre-existing Health Conditions

Simparica tablets contain sarolaner, a systemic acaricide that normally provides tick protection for approximately 30 days after administration. The expected duration assumes a healthy dog without underlying medical disorders that could alter drug absorption, distribution, metabolism, or excretion.

Dogs with the following pre‑existing conditions may experience a reduced protective period or require dosage adjustments:

Hepatic insufficiency – impaired liver function can slow metabolism of sarolaner, potentially leading to lower plasma concentrations and shorter efficacy.
Renal failure – altered elimination may cause subtherapeutic levels, decreasing the interval of tick control.
Congestive heart disease – fluid accumulation can affect drug distribution, influencing the duration of action.
Neurological disorders (e.g., epilepsy) – concurrent use of certain anticonvulsants may induce enzyme activity that metabolizes sarolaner more rapidly.
Immune‑mediated diseases – systemic inflammation can modify pharmacokinetic parameters, affecting the consistency of tick protection.

Veterinarians typically assess the severity of each condition, adjust the dosing schedule, or select an alternative ectoparasiticide when necessary. Regular monitoring of clinical response and tick exposure helps ensure that the intended protection period is maintained despite health challenges.

Comparing Simparica to Other Treatments

Topical vs. Oral Treatments

Convenience and Compliance

Simparica chewable tablets deliver systemic tick protection for a full month after a single oral dose. The product’s design eliminates the need for topical applications, bathing, or environmental treatments, allowing owners to maintain consistent coverage with minimal effort.

One tablet administered orally each month
Can be given with or without food
No water‑resistant requirements or environmental restrictions
Storage at room temperature, no refrigeration needed

These attributes simplify the routine for dog caregivers, reducing the likelihood of missed administrations. Reliable monthly dosing sustains the drug’s plasma concentration, preventing tick attachment throughout the treatment interval. Consistent compliance directly correlates with uninterrupted efficacy, minimizing the risk of tick‑borne disease transmission.

Other Oral Medications

Different Active Ingredients

Simparica contains the ectoparasiticide sarolaner, a member of the isoxazoline class. After oral administration, sarolaner maintains plasma concentrations sufficient to kill ticks for up to 35 days, allowing a single monthly dose to protect dogs throughout the entire interval.

Other isoxazoline products use different active ingredients with comparable but distinct efficacy windows:

Afoxolaner (found in NexGard) provides tick control for 30 days after a single tablet.
Fluralaner (Bravecto) is formulated for oral and chewable forms; a single dose protects for 84 days, covering three months.
Lotilaner (Credelio) achieves tick kill for 30 days, similar to afoxolaner.
Sarolaner (Simparica) delivers 35 days of activity, slightly longer than afoxolaner and lotilaner but shorter than fluralaner.

The duration of each ingredient’s efficacy depends on its pharmacokinetic profile, including absorption rate, half‑life, and tissue distribution. Sarolaner’s extended half‑life underlies the 35‑day protection window, while fluraler’s prolonged half‑life supports the three‑month claim. Selecting an appropriate product requires matching the required protection interval with the active ingredient’s proven tick‑killing period.

Efficacy Profiles

Simparica tablets contain sarolaner, a systemic acaricide that delivers continuous tick control after oral administration. Clinical trials demonstrate a single dose maintains ≥ 90 % efficacy against Ixodes scapularis, Rhipicephalus sanguineus, and Amblyomma americanum for a full month. Efficacy peaks within 24 hours of ingestion, with rapid tick kill observed in 12–48 hours across all tested species. Re‑treatment at 30‑day intervals restores the protective window without loss of potency.

Key efficacy parameters:

Onset of action: tick mortality begins 4 hours post‑dose, reaching ≥ 95 % by 24 hours.
Duration of protection: ≥ 90 % efficacy sustained for 35 days in controlled studies; field data confirm protection through the typical monthly dosing schedule.
Dose consistency: the labeled 2 mg/kg dosage provides uniform plasma concentrations, ensuring predictable tick kill rates across different dog weights.
Resistance profile: no documented sarolaner‑resistant tick populations in the United States; ongoing surveillance indicates stable efficacy.

The efficacy profile supports a monthly oral regimen as a reliable method for preventing tick‑borne diseases in canine patients.