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PetDosageChart

Antiparasitic combination · For Dogs

Simparica Trio dosage reference for dogs (Sarolaner / Moxidectin / Pyrantel)

This is a fixed-combination prescription product selected by labeled weight band. A single mg/kg result cannot describe all three active ingredients, so the main guide does not show a generic calculator.

Onset
4-8 hours (fleas)
Duration
30 days
Class
Antiparasitic combination

Weight-based calculator estimate from the references listed on this page. This page has not been independently DVM-reviewed — see our methodology .

This information is for educational purposes only. Always consult your veterinarian before giving medication to your pet. Do not use this calculator for emergencies, overdoses, pregnancy, very young animals, very old animals, pets with liver/kidney disease, or pets taking multiple medications.

Each medication page lists the references recorded for its data. The calculator math and editorial presentation are maintained by PetDosageChart; a page is independently DVM-reviewed only when a named reviewer byline appears. See our methodology and limitations.

Simparica Trio combines sarolaner, moxidectin, and pyrantel in one prescription chew used for flea, tick, heartworm, roundworm, and hookworm control. Because it contains three active ingredients and is sold in labeled dog-weight bands, a one-number calculator is not an appropriate way to choose the product.

The 1.2 mg/kg value in this site’s structured record corresponds to the sarolaner component. Moxidectin and pyrantel use different amounts and units, so adding the ingredients together as a single “combination dose” would be misleading.

No generic calculator on this page: Use the exact chew strength prescribed for your dog’s current labeled weight band. Do not calculate, split, or combine chews from a single mg/kg result.

What to Confirm Before the Monthly Dose

Confirm the dog’s current weight, the exact box strength, and the prescribed monthly date. Ask the veterinarian whether testing is required before starting or restarting heartworm prevention and what to do after a late or missed dose. Do not substitute a different isoxazoline or combine parasite products without a medication review.

The product’s three active ingredients address different parasites. A dog can still need testing, treatment, or a different prevention plan based on region, exposure, age, health history, and prior doses. The chew does not replace diagnosis when a dog is ill or already has a suspected parasite infection.

Dogs with a seizure history or a prior reaction to an isoxazoline need an explicit risk discussion. Record the time the chew was given and contact the clinic promptly for tremors, seizures, marked incoordination, persistent vomiting, facial swelling, or collapse.

How to Give Sarolaner / Moxidectin / Pyrantel to Your Dog

Follow the prescribing clinic’s directions for the exact chew strength and monthly date. The product label allows administration with or without food and instructs owners to ensure the full dose is consumed. Do not split the chew. Dogs should be tested for existing heartworm infection before administration as directed by the prescriber and product label.

Other isoxazoline products and P-glycoprotein inhibitors may require a medication review before use.

Side Effects and Safety

Common side effects include vomiting, diarrhea, lethargy, and decreased appetite. More serious side effects can occur, such as seizures (rare, in dogs with seizure history), tremors, ataxia, and severe allergic reaction.

Cautions · 12

When Simparica Trio should be used with caution or avoided

Some dogs should not take Simparica Trio, or need a different dose and closer monitoring. Tell your veterinarian about your pet's full health history and every other medication or supplement they take before giving Simparica Trio.

  • dogs under 8 weeks of age
  • dogs under 2.8 lbs
  • dogs with seizure history (use with caution)

Interactions · 13

Simparica Trio drug interactions

Simparica Trio can interact with other drugs. This list is not complete — always give your veterinarian a full list of your dog's medications and supplements.

other isoxazoline products
P-glycoprotein inhibitors

Calculator Limits · 14

When not to use this calculator

This calculator gives a general educational estimate for a healthy adult dog at a known weight. Do not rely on it in these situations — talk to your veterinarian instead:

  • In an emergency, or after accidental ingestion or a suspected overdose
  • For pregnant or nursing pets
  • For very young or very old dogs
  • For pets with liver disease, kidney disease, or another chronic illness
  • For pets taking several medications at once
  • When you are not sure of your dog's current, accurate weight
  • For combination products that contain additional active ingredients

Overdose · 15

Suspected overdose: what to do

If you think your dog had too much Simparica Trio, or swallowed any medication by accident, act right away. Do not wait for symptoms to appear.

  • Call your veterinarian or the nearest emergency animal hospital.
  • ASPCA Animal Poison Control Center: (888) 426-4435
  • Pet Poison Helpline: (855) 764-7661

A consultation fee may apply to the poison hotlines. Have the medication packaging ready, and note how much your pet may have taken and when. Do not try to make your pet vomit unless a veterinarian tells you to.

When to Call the Vet

If your dog experiences any of the following, contact your veterinarian or an emergency clinic immediately:

Frequently Asked Questions

Frequently Asked · 07

Questions about this medication

What is the Simparica Trio dosing chart for dogs by weight?
The US product label uses 6 color-coded prescription strengths: yellow for 2.8–5.5 lb (3 mg sarolaner), purple for 5.6–11 lb (6 mg), caramel for 11.1–22 lb (12 mg), teal for 22.1–44 lb (24 mg), green for 44.1–88 lb (48 mg), and brown for 88.1–132 lb (96 mg). A veterinarian selects the prescribed strength; do not choose, split, or combine chews from this page.
What is the Simparica Trio dose for a 10 lb dog?
A 10 lb dog lies within the label's 5.6–11 lb band, whose purple chew contains 6 mg sarolaner, 0.12 mg moxidectin, and 25 mg pyrantel. This is label information, not authorization to administer it; use only the strength and schedule prescribed for the dog.
What is the Simparica Trio dose for a 25 lb dog?
A 25 lb dog lies within the label's 22.1–44 lb band, whose teal chew contains 24 mg sarolaner, 0.48 mg moxidectin, and 100 mg pyrantel. Confirm the current weight and prescribed box strength with the veterinarian rather than selecting it from this page.
What is the Simparica Trio dose for a 50 lb dog?
A 50 lb dog lies within the label's 44.1–88 lb band, whose green chew contains 48 mg sarolaner, 0.96 mg moxidectin, and 200 mg pyrantel. Use only the prescription and schedule issued for the dog.
What is the Simparica Trio dose for a 75 lb dog?
A 75 lb dog lies within the label's 44.1–88 lb band, whose green chew contains 48 mg sarolaner, 0.96 mg moxidectin, and 200 mg pyrantel. This label reference does not replace verification of the dog's current weight and prescription.
What is the Simparica Trio dose for a 100 lb dog?
A 100 lb dog lies within the label's 88.1–132 lb band, whose brown chew contains 96 mg sarolaner, 1.92 mg moxidectin, and 400 mg pyrantel. Dogs over 132 lb require a veterinarian-selected combination of strengths; do not combine chews independently.
What does Simparica Trio protect against?
Simparica Trio is an all-in-one monthly chewable that protects against 5 types of ticks, fleas, heartworm disease, roundworms, and hookworms. It is one of the most comprehensive single-tablet parasite preventions available for dogs.
Is Simparica Trio safe for dogs?
Simparica Trio is FDA-approved for its labeled indications in dogs at least 8 weeks old and weighing at least 2.8 lb. Its label also warns that neurologic adverse reactions, including tremors, ataxia, and seizures, have been reported with isoxazoline-class drugs. The prescriber should evaluate seizure history, other medications, age, and current health.
Can I give Simparica Trio without a heartworm test?
The product label instructs that dogs be tested for existing heartworm infection before administration. Ask the prescribing clinic to confirm testing and what is required before a first, restarted, late, or missed dose.
What if my dog vomits after taking Simparica Trio?
Contact the prescribing veterinarian if vomiting follows a dose, especially if the chew may not have been fully consumed or symptoms persist. Do not give another chew unless the clinic explicitly tells you to redose.

Related · 08

Related medications for dogs

Sources · 09

Sources & references

The structured medication record behind this page names the references below. The links open the publisher or official resource; they do not turn this page into a prescription for an individual animal.

Source names are shown at the record level; passage-level page and label citations are still being added. Read our methodology and limitations.

Transparency · 11

How this page was made

This page's structured medication record includes Plumb's Veterinary Drug Handbook among its source names. This fixed-combination product is presented without a generic weight-based calculator on its main guide. A source record is not the same as an individualized prescription or an independent clinical review.

Sources cited
  • Plumb's Veterinary Drug Handbook
  • Merck Veterinary Manual
Calculator formula
No generic calculator is shown because this product contains multiple active ingredients and is selected by prescription weight band. Use the exact labeled strength directed by the veterinarian.
Editorial owner
Prepared and maintained by the PetDosageChart editorial team, a software-led publisher and not a veterinary practice.
DVM review status
Not independently DVM-reviewed. A named reviewer and review date appear here only after a confirmed review.

More on our methodology and editorial process — how we source, calculate, and review dogs dosage data.

Safety · 10

More resources