Capstar for Dogs (Nitenpyram)
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What Is Capstar Used for in Dogs?
Capstar is an oral flea treatment for dogs that contains nitenpyram, a fast-acting ingredient that starts killing adult fleas within 30 minutes. It’s especially useful for quickly reducing flea populations before they can lay eggs and trigger an infestation.
Capstar is available over the counter and does not require a prescription.
If your dog already has fleas, Capstar can be used alongside other flea prevention treatments for comprehensive control in targeting immature fleas on your pet and in their environment.
Capstar is safe for puppies at least 4 weeks old and weighing at least 2 pounds.
Capstar can also be safely given to pregnant or lactating dogs.
How Capstar Works in Dogs
Capstar works by quickly killing adult fleas before they can lay eggs, helping to interrupt the flea life cycle. A single female flea can lay up to 2,000 eggs, which can develop into new adult fleas in about three weeks.
Because Capstar only targets adult fleas—not eggs, larvae, or pupae—additional doses or combination treatment with other flea preventatives may be needed to fully eliminate an infestation.
Fleas not only cause infestations and skin irritation, but they can also cause flea allergy dermatitis and tapeworms.
How To Give Capstar to Dogs
Capstar comes in two dosage strengths for dogs, based on weight. To ensure safe and effective treatment, it’s important to use the correct dose:
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11.4 mg for dogs weighing 2–25 pounds
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57 mg for dogs weighing 25.1–125 pounds
Always confirm your dog’s weight before dosing and follow the instructions on the product label for proper use.
Capstar can be given directly into your dog’s mouth; with a pill wrap or treat, like Greenies Pill Pockets; or mixed in a small portion of your dog’s food.
If you hide Capstar in food, watch closely to make sure your dog swallows it. If you’re not sure that your dog swallowed the tablet, it’s safe to give a second dose.
Missed a Dose?
A single dose of Capstar kills 90% of adult fleas on your dog within four hours. However, if your dog has a flea re-infestation, it’s safe to give another dose of Capstar up to once daily as needed to kill adult fleas.
Possible Side Effects of Capstar in Dogs
Some dogs may scratch more than usual after taking Capstar, typically due to flea activity rather than the medication itself. This reaction is usually temporary.
Other possible side effects include:
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Hyperactivity and panting
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Vocalization
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Loss of coordination (ataxia)
Seek emergency veterinary care if your dog shows severe symptoms such as:
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Difficulty breathing
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Significant lethargy
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Sudden loss of coordination
Serious reactions are more likely in dogs under 2 pounds, younger than 8 weeks, or in poor health.
Human Side Effects
Capstar is intended for pets only and should never be used by humans. Likewise, pets should not be given medications meant for human use.
If you accidentally ingest the medication, seek medical attention in person or call Poison Control at 800-222-1222.
When To Call Your Vet
Call your veterinarian if you see any of the following, or if you have additional questions or concerns about the use of Capstar:
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Severe side effects (above)
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Your pet’s condition worsens or does not improve with treatment
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You see or suspect an overdose
Capstar Overdose Concerns in Dogs
Overdoses are unlikely to cause significant problems. However, if you observe your dog exhibiting any abnormal signs or behaviors that you suspect may be related to an overdose, immediately contact your veterinarian or an animal poison control center. Consultation fees often apply.
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Pet Poison Helpline 855-764-7661
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ASPCA Animal Poison Control 888-426-4435
How To Store Capstar for Dogs
Keep these storage tips in mind for Capstar:
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Store at controlled room temperature between 59–77 F (15–25 C) in a cool, dry place away from direct sunlight.
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Keep tablets in its original packaging until ready to use.
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Keep out of reach of children and pets.
Capstar for Dogs FAQs
Is Capstar safe for dogs?
Yes, Capstar is generally safe for healthy dogs over 4 weeks old and weighing more than 2 pounds. However, always consult your veterinarian before use, especially if your dog has underlying health conditions or is ill.
Where can I buy Capstar for Dogs?
Capstar is available over the counter at most pet supply stores, online retailers, and veterinary offices.
How long does Capstar for dogs last?
Capstar begins working within 30 minutes and kills over 90% of adult fleas within four hours. However, its effects typically last for only 24 hours, so it may be used daily if needed or combined with a longer-term flea prevention plan.
How much does Capstar for dogs cost?
Prices vary based on the package size and retailer.
Is Capstar safe for pregnant dogs?
Yes, Capstar can be used safely in pregnant and lactating dogs.
No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer.
