What Is Simparica Chewables 20 Mg?

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Simparica is a brand-name parasite control medication for dogs; its active ingredient is sarolaner, which belongs to the isoxazoline class of insecticides/acaricides.

The 20 mg chewable tablet is one of the dose strengths made for small dogs. According to the manufacturer, the 20 mg is intended for dogs in the weight range of >5 kg to 10 kg. Order Simparica Chewables 20MG for Small Dogs!

It’s flavored (liver-like) so dogs often accept it like a treat.

It’s for oral use only in dogs older than 6 months (as per official prescribing info) and weighing at least 1.3 kg (or around 2.8 lb) in some regions.

How Does Simparica Work?

Sarolaner (the active agent) works by disrupting the nervous system of parasites (fleas and ticks). It targets neurotransmitter receptors (GABA and glutamate) in the parasites, causing uncontrolled neuromuscular activity, which kills them.

Because it is systemic (i.e., absorbed into the bloodstream), parasites must bite and begin feeding to ingest a lethal ...
... dose.

Speed of action:

Kills adult fleas rapidly — in controlled studies, Simparica started killing fleas within 3 hours of administration.

Ticks: it begins killing ticks within 8 hours after administration in some species.

Duration: A single dose protects for a month (administered monthly).

Key Benefits for Small Dogs

Convenience & Compliance

As a chewable, it’s easier to give than topical treatments, especially for small dogs that may not tolerate topical spot-ons.

Monthly dosing helps maintain consistent protection.

Broad Spectrum Protection

Effective against adult fleas (especially Ctenocephalides felis).

Covers multiple tick species: e.g., black-legged tick (Ixodes scapularis), brown dog tick (Rhipicephalus sanguineus), Gulf Coast tick, Lone Star tick, and others.

Prevents Lyme disease via tick control: Simparica helps in reducing the risk of Borrelia burgdorferi infection by killing vector ticks.

Palatability

High acceptability: In studies, a very large percentage of dogs voluntarily ate the tablet quickly when offered.

Can be given with food or directly by hand.

Quick Onset

Because of its fast action, Simparica starts protecting soon after administration — useful in preventing immediate infestations.

Dosage for Small Dogs (20 mg Strength)

The official dose is based on weight to achieve about 2 mg of sarolaner per kg (or roughly 0.91 mg/lb) of body weight.

For small dogs:

Dogs weighing >5 kg to ≤10 kg: 1 × 20 mg tablet monthly.

Always observe your dog after giving the tablet to ensure full consumption; some chews may be spat out or rejected.

If a dose is missed, the recommendation is to administer as soon as possible and then resume monthly dosing.

Safety & Precautions

Simparica is generally well-tolerated, but like all medications, it has potential risks. Here’s what you should know:

Age & Weight Constraints

Not for use in puppies below 6 months of age (in some regions) or dogs under a certain weight (varies by country).

According to some regulatory inserts, avoid in dogs under 1.3 kg.

Use in pregnant or lactating dogs hasn’t been well studied.

Neurological Risks

Because sarolaner is an isoxazoline, there is a risk of neurological side effects: tremors, ataxia (uncoordinated movements), seizures.

Use caution (or avoid) in dogs with a history of seizures or other neurological disorders.

Other Adverse Effects

Commonly reported side-effects: vomiting, diarrhea.

In post-approval experience, additional reported reactions include lethargy, inappetence, hyperactivity, hypersalivation.

Storage & Handling

Store tablets in a cool, dry place; recommended storage is at or below 30 °C.

After handling the tablets, wash your hands.

Keep out of reach of children and other animals.

Drug Interactions & Contraindications

No well-documented major drug interactions, but always tell your vet about other medications or supplements your dog takes.

Hypersensitivity: Do not use if your dog is known to be allergic to sarolaner or any excipients.

Real-World Risks: What Some Pet Owners Report

Though many dogs tolerate Simparica well, there are anecdotal reports from pet owners about neurological effects:

“My Primmie had seizures … when I gave her Simparica trio … she had these tremors …”

Others report milder side effects like vomiting, tiredness, or diarrhea after dosing.

These experiences underscore the importance of starting with veterinary guidance, especially for small or sensitive dogs.

Tips for Best Use

Vet Consultation

Always consult your vet before starting Simparica. They will assess whether it's suitable, considering your dog’s health history, weight, and risk of fleas/ticks.

Consistent Monthly Schedule

Give the tablet on the same day every month to maintain steady protection.

Observe After Giving

After administering, watch your dog for a few minutes to make sure the full tablet is consumed. If not, you may need to re-dose, but only after discussing with your vet.

Monitor for any side-effects, especially during the first few doses.

Complementary Prevention

While Simparica kills fleas and ticks systemically, environmental control (bedding cleaning, vacuuming, treating other pets) helps reduce re-infestation.

Treat all pets in a household if fleas are a problem — this breaks the infestation cycle.

Be Cautious in At-Risk Dogs

If your dog has a seizure history or neurological issues, talk to your vet about risk vs benefit.

If side-effects occur, report them to your vet immediately.

Pros & Cons: Is Simparica 20 mg a Good Choice for Small Dogs?

Pros:

Easy to give — chewable tablet, tasty.

Monthly protection.

Broad coverage: fleas + multiple tick species.

Rapid onset of action.

High compliance.

Cons / Risks:

Neurological side-effects in some dogs (rare, but possible).

Requires strict weight-based dosing.

Not for very young puppies or very small dogs (depending on label).

No protection for internal parasites (unless using a combo like Simparica Trio).

Conclusion

Simparica Chewables 20 mg can be an excellent choice for small dogs (5–10 kg) needing effective and convenient flea and tick protection. Its fast action, palatable chew, and monthly dosing make it user-friendly — but like any systemic parasiticide, it carries some risks, particularly neurological effects. The key to safe and effective use is veterinary guidance, correct dosing, and close monitoring, especially when starting or if your pet has a sensitive background.

If you’re considering Simparica for your small dog, talk to your vet about its suitability, discuss any health concerns, and set up a plan for monthly administration and follow-up. With the right approach, it can help keep your dog free from fleas and ticks in a hassle-free way.