What Does Simparica Trio Cover? All-in-One Parasite Prevention

For dog owners across the U.S., keeping up with parasite prevention can feel overwhelming. Heartworm. Fleas. Ticks. Roundworms. Hookworms. Every threat seems to call for a different product, a different schedule, and a different bill. Simparica Trio was developed to solve that problem. One chewable tablet given once a month covers five major parasite categories at the same time. This guide breaks down exactly what Simparica Trio covers, how it works, and what dog owners should know before they start their dog on it.

What Is Simparica Trio?

Simparica Trio (sarolaner, moxidectin, and pyrantel chewable tablets) is an FDA-approved prescription chewable tablet for dogs 8 weeks of age and older, weighing 2.8 lbs or more. It is manufactured by Zoetis and approved under NADA #141-521, with the prescribing information last revised in October 2024.

The tablet combines three active pharmaceutical ingredients. Sarolaner is an acaricide and insecticide in the isoxazoline class. It works by blocking the neurotransmitter gamma aminobutyric acid (GABA) receptor and glutamate receptor, which disrupts neuromuscular function in insects and acarines. Moxidectin is a macrocyclic lactone endectocide that kills parasites by interfering with chloride channel-mediated neurotransmission. Pyrantel pamoate is a nematocide that acts as a depolarizing neuromuscular-blocking agent in susceptible parasites, causing paralysis and expulsion.

Together, these three mechanisms target a broad range of parasites through two entirely different action pathways, which is why one tablet covers as much ground as it does.

What Parasites Does Simparica Trio Cover?

Heartworm Prevention

Simparica Trio is indicated for the prevention of heartworm disease caused by Dirofilaria immitis. In two well-controlled laboratory studies, a single oral dose was 100% effective in preventing the development of adult D. Immitis when given to dogs exposed to infective larvae 30 days before treatment. For continuous protection, the product must be administered on a monthly schedule beginning within one month of the animal’s first seasonal exposure to mosquitoes and continuing for at least one month after mosquito season ends.

One critical note from the prescribing label: Simparica Trio is not effective against adult D. Immitis. Dogs must be tested for existing heartworm infections before starting, and any active infection must be treated with an adulticide product first.

Flea Treatment and Prevention

Sarolaner begins killing fleas within 4 hours of administration. After weekly re-infestations in a controlled laboratory study, Simparica Trio reduced the number of live fleas by greater than 97.8% within 12 hours of infestation for 28 days. In a separate study, 100% effectiveness against adult fleas was demonstrated within 24 hours and maintained at or above 99.7% effectiveness against weekly re-infestations for 35 days.

The product also targets flea egg production. In a study exploring flea egg production and viability, Simparica Trio killed fleas before they could lay eggs for 35 days. Treatment should begin at monthly intervals or at least one month before fleas become active in the dog’s environment.

Tick Treatment and Control

Simparica Trio kills six tick species. It began killing Ixodes scapularis (black-legged tick) within 8 hours in controlled studies, with a tick reduction rate of greater than 94.2% within 24 hours of infestation for 28 days.

Against Amblyomma americanum (lone star tick), the product demonstrated greater than or equal to 98.9% effectiveness after treatment of existing infestations, maintaining greater than or equal to 90.4% effectiveness 48 hours post re-infestation. It is also indicated against Amblyomma maculatum (Gulf Coast tick), Dermacentor variabilis (American dog tick), Rhipicephalus sanguineus (brown dog tick), and Haemaphysalis longicornis (Asian longhorned tick). Additionally, Simparica Trio carries an indication for prevention of Borrelia burgdorferi infections as a result of killing Ixodes scapularis vector ticks.

Intestinal Nematode Treatment and Control

Simparica Trio eliminates roundworms and hookworms. Specifically, it treats and controls immature adult and adult Toxocara canis and adult Toxascaris leonina (roundworms), along with hookworm species including L4 immature adult and adult Ancylostoma caninum and Uncinaria stenocephala. In well-controlled laboratory studies, the product was effective against Toxocara canis and reduced fecal egg counts by 99.2%.

Simparica Trio Dosage Schedule

Each tablet is weight-specific, formulated to deliver a minimum dose of 0.54 mg/lb (1.2 mg/kg) sarolaner, 0.011 mg/lb (0.024 mg/kg) moxidectin, and 2.27 mg/lb (5 mg/kg) pyrantel as pamoate salt. The pack color helps owners identify the correct size at a glance.

Product	Sarolaner (mg)	Moxidectin (mg)	Pyrantel (mg)	Pack Color
Simparica Trio 2.8–5.5 lbs (1.25–2.5 kg)	3	0.06	12.5	Yellow
Simparica Trio 5.6–11 lbs (2.6–5 kg)	6	0.12	25	Purple
Simparica Trio 11.1–22 lbs (5.1–10 kg)	12	0.24	50	Orange
Simparica Trio 22.1–44 lbs (10.1–20 kg)	24	0.48	100	Blue
Simparica Trio 44.1–88 lbs (20.1–40 kg)	48	0.72	200	Green
Simparica Trio 88.1–132 lbs (40.1–60 kg)	72	1.44	300	Red/Brown

For dogs over 132 lbs, the appropriate combination of tablets is administered. The chewable can be given with or without food. If a dose is missed, give it immediately and resume monthly dosing. Pet owners who want to maintain a consistent monthly schedule can browse FDA-approved dog medications through online pet pharmacy Anipetshop to keep preventatives on hand year-round.

Safety Considerations Dog Owners Should Know

The prescribing label carries several important safety notes. Simparica Trio is not for use in humans. The isoxazoline class has been associated with neurologic adverse reactions, including tremors, ataxia, and seizures. These have been observed in dogs receiving isoxazoline-class drugs, including those without a prior history of seizures. Dogs with a known history of seizures or neurologic disorders require caution.

In a field safety and effectiveness study of 272 treated dogs over 330 days, the most frequent adverse reactions recorded in the Simparica Trio group were vomiting (14.3%), diarrhea (13.2%), lethargy (8.5%), anorexia (5.1%), polyuria (3.7%), hyperactivity (2.2%), and polydipsia (2.2%). Dogs in ivermectin-sensitive collie breeds should be screened for ivermectin sensitivity before use. The product has not been evaluated in breeding, pregnant, or lactating dogs.

Where to Get Simparica Trio

Simparica Trio is a prescription medication. Federal law restricts it to use on order of a licensed veterinarian. Dogs must be tested for existing heartworm disease before starting, and active infections need adulticide treatment prior to beginning the prevention protocol.

Once a vet authorizes the prescription, pet owners can fill it through a licensed source. All six weight-based sizes of Simparica Trio for dogs at Anipetshop are available through their online catalog, making it straightforward to order the correct pack and stay on schedule each month.

Final Takeaway

Simparica Trio covers five major parasite categories with a single monthly chewable: heartworm prevention, flea treatment and prevention, tick treatment and control across six species, and intestinal roundworm and hookworm control. The three active ingredients, sarolaner, moxidectin, and pyrantel, each work through different mechanisms to deliver broad-spectrum protection in one tablet. Dog owners should confirm their pet’s heartworm status with a vet before starting, select the correct weight-based size from the dosage table above, and administer it consistently each month throughout the year.