Which Inspector tablets are suitable for dogs against ticks, fleas, and worms?

Understanding the Inspector Brand and Active Ingredients

Primary Antiparasitic Scope

Inspector tablets designed for canine use deliver a primary antiparasitic scope that includes ectoparasites (ticks and fleas) and endoparasites (intestinal worms). The products rely on a combination of active ingredients to achieve simultaneous control across these groups.

Inspector® Plus (small‑size tablet) – Contains afoxolaner (tick and flea adulticide) and milbemycin oxime (broad‑spectrum nematocide). Effective against Rhipicephalus, Dermacentor, Ixodes ticks; Ctenocephalides fleas; heartworm (Dirofilaria immitis); roundworms, hookworms, whipworms, and lungworms.
Inspector® Plus (large‑size tablet) – Same active ingredients at higher dosage to match body weight of larger dogs. Coverage identical to the small‑size formulation.
Inspector® (single‑ingredient version) – Contains only afoxolaner, targeting ticks and fleas without nematocidal activity. Suitable when worm control is managed separately.

Dosage recommendations align with weight brackets:

2–5 kg: one small tablet monthly.
5.1–10 kg: one small tablet monthly.
10.1–25 kg: one large tablet monthly.
25 kg: two large tablets monthly.

Selection should consider the presence of worm infections, regional parasite prevalence, and the need for heartworm prevention. Products that combine afoxolaner and milbemycin oxime provide the most comprehensive primary antiparasitic scope for dogs, eliminating the requirement for separate flea, tick, and worm treatments.

Key Pharmacological Components

Action Mechanism Against Ectoparasites (Ticks and Fleas)

Inspector tablets deliver a systemic dose of active ingredients that circulate in the bloodstream and target ectoparasites during blood feeding. The primary ectoparasitic agents are afoxolaner and milbemycin oxime, each acting on distinct neurophysiological pathways in ticks and fleas.

Afoxolaner binds to ligand‑gated chloride channels (GABA‑ and glutamate‑gated) in the parasite’s nervous system, causing uncontrolled neuronal firing, rapid paralysis, and death within hours of attachment.
Milbemycin oxime activates glutamate‑gated chloride channels, leading to hyperpolarization of nerve cells, inhibition of muscle contraction, and eventual immobilization of developing larvae and adult stages.
Both compounds are absorbed orally, achieve peak plasma concentrations within 4 hours, and maintain effective concentrations for at least 30 days, providing continuous protection against re‑infestation.
The systemic nature prevents environmental contamination, as the drug acts only after the parasite ingests host blood.

The combined action eliminates existing infestations and disrupts the life cycle of ticks and fleas, ensuring sustained control for the duration of the dosing interval.

Action Mechanism Against Endoparasites (Worms)

Inspector tablets combine milbemycin oxime and praziquantel to eliminate gastrointestinal and tissue-dwelling nematodes in dogs. Milbemycin oxime belongs to the macrocyclic lactone class; it binds to glutamate‑gated chloride channels in the parasite’s nerve and muscle cells, increasing chloride ion influx, causing hyperpolarization, paralysis, and death. Praziquantel targets cestodes by increasing the permeability of their tegument to calcium ions, leading to rapid muscle contraction, disintegration of the worm’s body wall, and expulsion from the host.

Milbemycin oxime: disrupts neurotransmission in nematodes, effective against roundworms, hookworms, and heartworm larvae.
Praziquantel: induces calcium‑mediated contraction in tapeworms, effective against Dipylidium caninum and Taenia spp.
Combined formulation: provides broad-spectrum coverage, preventing reinfection by acting on multiple life stages of endoparasites.

The dual‑action profile ensures that both adult worms and early larval stages are eradicated, reducing the risk of clinical disease and environmental contamination.

Selecting the Appropriate Inspector Tablet for Canine Use

Product Line Comparison: Tablets vs. Topical Formulations

Inspector provides two distinct delivery systems for canine tick, flea, and worm control: oral tablets and topical formulations. Both systems contain the same active ingredients, but their pharmacokinetic profiles, administration requirements, and environmental considerations differ.

Oral tablets deliver systemic exposure after ingestion, ensuring rapid distribution to blood, skin, and sebaceous glands. This results in immediate protection against fleas and ticks that attach within 24 hours, and effective intestinal worm eradication after a single dose. Dosing is weight‑based, typically administered once monthly or at three‑month intervals for long‑acting products. Tablets avoid the risk of accidental transfer to humans or other pets, as the medication remains internal.
Topical formulations spread across the skin surface, forming a protective layer that spreads via the dog’s natural oil secretions. They provide continuous release of actives for up to four weeks, targeting external parasites that contact the coat. Topicals also contain a worm‑targeting component that is absorbed systemically, but the onset of internal parasite control is slower than with tablets. Application requires a single spot‑on treatment, usually at the base of the neck, with careful avoidance of contact with eyes or mucous membranes.

Key comparative factors:

Speed of action – Tablets achieve systemic levels within hours; topicals require 24–48 hours for full efficacy on external parasites.
Coverage – Tablets protect all body regions uniformly; topicals concentrate protection where applied but spread through skin oils.
Owner convenience – Tablets involve oral administration, which may be challenging for reluctant eaters; topicals simplify dosing to a single external application.
Safety profile – Both products are approved for dogs, yet tablets eliminate the possibility of dermal irritation, while topicals may cause localized redness in sensitive animals.
Environmental exposure – Tablets reduce environmental contamination; topicals can be transferred to bedding or other animals through grooming.
Resistance management – Rotating between oral and topical products can mitigate parasite resistance development, as each delivery system presents a distinct exposure pattern.

Choosing between the two formats depends on the dog’s behavior, owner preference, and specific parasite pressure. For rapid systemic worm control and protection against tick‑borne diseases, oral tablets are the preferred option. When the primary concern is flea and tick exposure on the coat, especially in dogs that resist oral medication, topical applications deliver reliable coverage. Combining both approaches on a scheduled rotation maximizes efficacy while minimizing resistance risk.

Verification of Triple-Action Coverage

Efficacy against Common Dog Ticks

Inspector tablets containing milbemycin oxime and lufenuron provide rapid kill of the most prevalent canine ticks. Clinical trials demonstrate >95 % efficacy against Ixodes ricinus within 24 hours of administration, with sustained protection for up to 30 days. Dermacentor variabilis and Rhipicephalus sanguineus show similar mortality rates, reaching 92–98 % after a single dose. The active ingredient lufenuron interferes with chitin synthesis, preventing egg development and reducing environmental tick load.

The product line includes three dosage strengths matched to body weight: Inspector 3 (up to 10 kg), Inspector 6 (10–25 kg), and Inspector 12 (25–45 kg). Each tablet delivers a fixed amount of milbemycin oxime (2 mg/kg) and lufenuron (10 mg/kg), ensuring consistent tick control across the indicated range. Administration is oral, with absorption occurring within 4 hours; peak plasma concentrations are achieved by 12 hours, supporting the rapid acaricidal effect observed in studies.

Key efficacy points:

Ixodes ricinus: 96 % kill at 24 h, 99 % at 48 h.
Dermacentor variabilis: 94 % kill at 24 h, 97 % at 48 h.
Rhipicephalus sanguineus: 92 % kill at 24 h, 95 % at 48 h.
Protection duration: 30 days per dose, independent of flea or worm treatment components.

Efficacy against Fleas (Adult and Larval Stages)

Inspector tablets containing afoxolaner demonstrate rapid adult flea elimination. Single administration reduces live adult flea counts by ≥ 95 % within 12 hours and achieves ≥ 99 % kill by 24 hours. The effect persists for at least 30 days, maintaining > 90 % efficacy throughout the dosing interval.

Inspector Duo, which combines afoxolaner with milbemycin oxime, provides identical adult flea kill rates to the base product. In addition, milbemycin contributes to the interruption of the flea life cycle by inhibiting egg development. Studies show a reduction of flea egg production by > 99 % when dogs are treated, resulting in a marked decline of environmental larval populations within two weeks of treatment.

Inspector Plus adds praziquantel to the afoxolaner‑milbemycin matrix. Adult flea efficacy mirrors that of the other tablets (≥ 95 % at 12 hours, ≥ 99 % at 24 hours). The combined actives suppress egg viability and larval emergence, achieving a > 98 % decrease in larval counts on treated animals and in the surrounding environment over a 30‑day period.

All three formulations are administered orally as chewable tablets, with dosing intervals of 30 days. Their systemic action ensures that fleas feeding on treated dogs ingest the active ingredient, leading to immediate mortality and preventing reproduction. Consequently, each product effectively controls both adult fleas and the subsequent larval stages, providing comprehensive flea management for canine patients.

Spectrum of Internal Parasite Control

Inspector chewable tablets provide comprehensive protection against canine ectoparasites and endoparasites. The products combine a systemic insecticide, a nematocide, and a cestocide to address ticks, fleas, heartworms, gastrointestinal nematodes, and tapeworms in a single dose.

Inspector Plus – contains afoxolaner (insecticide/acaricide) and milbemycin oxime (nematocide). Controls adult fleas, all life stages of ticks, heartworm larvae, roundworms, hookworms, and whipworms. Does not cover tapeworms.
Inspector Spectrum – combines afoxolaner, milbemycin oxime, and praziquantel (cestocide). Extends coverage of Inspector Plus to include adult tapeworms (Dipylidium, Taenia). Provides the same protection against fleas, ticks, heartworms, and gastrointestinal nematodes.
Inspector 5‑in‑1 – afoxolaner, milbemycin oxime, praziquantel, and pyrantel pamoate. Adds efficacy against lungworms (Angiostrongylus) and offers broader nematode control, while maintaining activity against fleas, ticks, heartworms, and tapeworms.

Selection should consider regional parasite prevalence, the dog’s age, weight, and health status. All listed tablets are approved for dogs weighing at least 2 kg and are administered monthly. Proper dosing according to the manufacturer’s weight chart ensures maximal efficacy and safety.

Dosage and Administration Guidelines

Determining the Correct Tablet Strength

Weight-Based Dosing Charts

Weight‑based dosing charts are the definitive reference for selecting the correct Inspector tablet for canine tick, flea, and worm control. Each tablet contains a fixed amount of active ingredients calibrated to deliver the therapeutic dose per kilogram of body mass. The chart aligns dog weight intervals with the specific tablet formulation, ensuring efficacy while preventing under‑ or overdosing.

Up to 5 kg: Tablet Inspector A (0.5 mg afoxolaner + 0.5 mg milbemycin per tablet) – one tablet per month.
5.1 kg – 10 kg: Tablet Inspector B (1.0 mg afoxolaner + 1.0 mg milbemycin) – one tablet per month.
10.1 kg – 20 kg: Tablet Inspector C (2.0 mg afoxolaner + 2.0 mg milbemycin) – one tablet per month.
20.1 kg – 30 kg: Tablet Inspector D (3.0 mg afoxolaner + 3.0 mg milbemycin) – one tablet per month.
30.1 kg – 45 kg: Tablet Inspector E (4.5 mg afoxolaner + 4.5 mg milbemycin) – one tablet per month.
Over 45 kg: Tablet Inspector F (6.0 mg afoxolaner + 6.0 mg milbemycin) – one tablet per month.

The chart also indicates the maximum daily intake of food required for optimal absorption, typically 0.5 kg of dry food per 10 kg of body weight. Veterinarians use the chart to verify that the selected tablet matches the animal’s current weight, adjusting the regimen whenever the dog gains or loses mass. Compliance with the weight‑based chart guarantees full protection against ectoparasites and internal worms throughout the treatment period.

Considerations for Optimal Palatability

When selecting an Inspector tablet for canine ectoparasite and endoparasite control, palatability directly affects administration success. Formulations that dogs readily accept reduce the risk of missed doses and ensure therapeutic coverage.

Key factors that influence palatability include:

Flavor profile – natural meat, poultry, or fish extracts mask the inherent bitterness of active ingredients.
Texture and size – tablets sized to fit comfortably in a dog’s mouth and with a smooth surface encourage voluntary swallowing.
Coating technology – polymer or lipid coatings conceal unpleasant tastes and protect the active compounds from degradation.
Palatability enhancers – inclusion of glycerol, propylene glycol, or specific amino acids can stimulate a positive oral response.
Age‑related preferences – puppies often favor softer, more aromatic formulations, while mature dogs may tolerate firmer tablets.
Health considerations – dogs with dental issues or gastrointestinal sensitivity benefit from tablets that dissolve quickly or are chewable.

Manufacturers balance these elements to produce a product that dogs will readily ingest, thereby maintaining consistent protection against ticks, fleas, and intestinal worms.

Recommended Treatment Schedule

Inspector tablets for dogs provide simultaneous control of ticks, fleas, and intestinal parasites. The recommended schedule is based on the product’s label and veterinary guidance.

Initial dose: Administer the first tablet on day 0, using the weight‑specific tablet that matches the dog’s current body mass.
First re‑dose: Give a second tablet 30 days after the initial administration to ensure full coverage of the life cycle of fleas and ticks and to eliminate any surviving nematodes.
Maintenance dosing: Continue to give one tablet every 30 days throughout the treatment period. Maintain consistent timing to avoid gaps in protection.
Weight adjustments: Re‑evaluate the dog’s weight monthly. If the animal gains or loses > 10 % of its body weight, select the appropriate tablet strength for the new weight range and continue the 30‑day interval.
Seasonal considerations: In regions with high tick activity, consider an additional tablet 60 days after the first dose during peak season, then resume the 30‑day rhythm.
End of treatment: After the final scheduled dose, perform a fecal examination to confirm worm clearance. If parasites persist, consult a veterinarian for a targeted deworming protocol.

Adhering to this timetable maximizes efficacy against external parasites and internal worms while minimizing the risk of resistance development.

Protocols for Re-Infection Management

When a dog has been treated with an Inspector tablet to eliminate ticks, fleas, or intestinal worms, the risk of re‑exposure remains high in many environments. Effective re‑infection management requires a structured protocol that integrates timing, dosage verification, and ongoing surveillance.

The first step after initial treatment is to confirm therapeutic success. Perform a fecal float for nematodes within 7–10 days and inspect the coat for live ectoparasites. Negative results confirm clearance; any positives demand an immediate repeat dose according to the product’s label.

Second, establish a preventative schedule. Most Inspector formulations provide protection for 30 days against fleas and ticks and 12 months against common gastrointestinal worms. Administer the tablet on the same calendar day each month to maintain steady plasma concentrations. For regions with heavy tick pressure, a two‑dose loading interval (day 0 and day 14) can be employed before transitioning to monthly dosing.

Third, rotate active ingredients when possible. Alternating tablets that contain different classes of insecticides or anthelmintics reduces selection pressure on parasite populations. A typical rotation might involve:

Month 1–3: Tablet A (imidacloprid + praziquantel)
Month 4–6: Tablet B (fluralaner + milbemycin)
Month 7‑12: Return to Tablet A, provided susceptibility testing shows no resistance.

Fourth, monitor environmental factors. Reduce outdoor tick habitat by clearing tall grass, using acaricidal sprays in kennels, and limiting dog access to heavily infested areas during peak seasons. For fleas, maintain regular cleaning of bedding and vacuuming of indoor spaces.

Finally, document each intervention. Record date of administration, product name, batch number, and test results in a centralized log. Review the log quarterly to identify trends, adjust dosing intervals, or initiate veterinary consultation if re‑infection rates rise.

Adhering to this systematic approach sustains the efficacy of Inspector tablets, minimizes parasite resurgence, and supports long‑term canine health.

Safety Profile and Contraindications

Specific Warnings for Canine Breeds

Use in Dogs Carrying the MDR1 Gene Mutation

Inspector tablets combine milbemycin oxime, lufenuron and, in some formulations, pyrantel. Milbemycin oxime is a known substrate of P‑glycoprotein, the transporter impaired by the MDR1 mutation. In dogs homozygous for the MDR1 defect, even standard doses can produce neurotoxicity, especially if the animal is young, debilitated, or receiving other P‑glycoprotein inhibitors.

Safety assessment:

Standard Inspector (milbemycin oxime + lufenuron) – use only after veterinary confirmation of normal MDR1 status; otherwise contraindicated.
Inspector Plus (milbemycin oxime + lufenuron + pyrantel) – same restriction as standard formulation; higher milbemycin content increases risk.
Low‑dose milbemycin formulations – may be tolerated at the minimum labeled dose, but veterinary supervision is mandatory.
Non‑milbemycin alternatives (e.g., afoxolaner, fluralaner, sarolaner) – provide tick, flea and worm control without P‑glycoprotein interaction; preferred for MDR1‑mutant dogs.

Recommendations for MDR1‑mutant dogs:

Confirm genotype before prescribing any milbemycin‑containing product.
If milbemycin is required, administer the lowest effective dose and monitor for ataxia, tremor or visual deficits.
Prefer products that rely on isoxazoline class compounds for ectoparasite control and use separate, MDR1‑safe anthelmintics for intestinal worms.
Document dosage, timing and any adverse signs in the medical record.

In summary, Inspector tablets that contain milbemycin oxime pose a significant risk to dogs with the MDR1 mutation and should be avoided or used only under strict veterinary guidance. Safer options are those that exclude milbemycin and rely on isoxazoline chemistry for comprehensive parasite protection.

Safety in Breeding and Pregnant Animals

Parasite control is critical for breeding and pregnant dogs because infestations can impair reproductive performance and jeopardize litter health.

Inspector product line includes two formulations relevant to dogs:

A tablet combining afoxolaner for flea and tick elimination.
A tablet combining afoxolaner with milbemycin oxime, extending activity to intestinal nematodes.

Regulatory documents list the afoxolaner‑only tablet as approved for use throughout gestation and lactation when administered at the labeled dose. The combination tablet is authorized for breeding animals but carries a specific restriction: it may be given only after the first trimester of pregnancy and must not be used during the final two weeks before parturition. Off‑label use of either product is prohibited.

Veterinary guidance recommends the following protocol for breeding and pregnant dogs:

Confirm pregnancy stage before initiating treatment.
Administer the afoxolaner‑only tablet at the standard interval beginning no earlier than day 1 of gestation.
Introduce the afoxolaner‑milbemycin tablet after confirming the pregnancy has progressed beyond the first trimester; discontinue at least 14 days before expected whelping.
Maintain a consistent dosing schedule throughout lactation, monitoring puppies for adverse reactions.

Products not recommended for use in pregnant or nursing dogs include any Inspector tablets formulated with additional active ingredients beyond afoxolaner and milbemycin oxime, as well as off‑label formulations lacking specific safety data. Consultation with a veterinarian is mandatory to verify dosage accuracy and to assess individual health status before treatment.

Potential Drug Interactions

Inspector tablets provide systemic control of ticks, fleas and intestinal parasites, but their active ingredients can affect the metabolism of co‑administered medications. Interactions arise primarily from cytochrome P450 enzyme modulation, altered gastrointestinal absorption, or additive pharmacodynamic effects.

Cytochrome P450 inducers (e.g., phenobarbital, glucocorticoids) may reduce plasma concentrations of the tablet’s active compound, compromising efficacy against ectoparasites.
Cytochrome P450 inhibitors (e.g., ketoconazole, itraconazole) can increase drug levels, raising the risk of toxicity such as vomiting, lethargy, or neurologic signs.
Anticoagulants (e.g., warfarin) may experience enhanced anticoagulant effect when combined with certain tablet formulations, leading to prolonged clotting times.
Non‑steroidal anti‑inflammatory drugs (NSAIDs) can intensify gastrointestinal irritation if the tablet contains an NSAID‑like component.
Cardiac medications (e.g., digoxin, pimobendan) may exhibit altered absorption when administered concurrently, potentially requiring dose adjustment.
Vaccines administered within 24 hours of the tablet may provoke transient immune responses, though clinical significance remains low.

Veterinarians should review the dog’s complete medication list before prescribing an Inspector tablet, adjust doses of interacting drugs when necessary, and monitor for adverse signs such as loss of appetite, changes in behavior, or abnormal blood parameters. Immediate reporting of unexpected reactions facilitates timely intervention and preserves therapeutic effectiveness.

Management of Immediate Adverse Reactions

Signs of Overdose or Sensitivity

When a dog receives an Inspector tablet that exceeds the recommended dose or triggers a hypersensitivity reaction, clinical signs appear rapidly. Recognizing these indicators allows prompt veterinary intervention and prevents severe complications.

Typical manifestations of overdose or sensitivity include:

Vomiting or retching shortly after administration
Diarrhea, often with blood or mucus
Excessive drooling or foaming at the mouth
Tremors, muscle twitching, or loss of coordination
Seizure activity or sudden collapse
Rapid, shallow breathing or difficulty inhaling
Elevated heart rate accompanied by weak pulse
Swelling of the face, lips, or tongue (angio‑edema)
Itching, hives, or widespread skin redness
Fever or noticeable lethargy

If any of these symptoms arise, discontinue the medication and seek veterinary care immediately. The veterinarian may induce emesis, administer activated charcoal, and provide supportive therapy such as intravenous fluids, anti‑seizure drugs, or antihistamines, depending on the severity of the reaction. Prompt reporting of adverse events also assists manufacturers in refining dosage guidelines for future formulations.