Nexgard Spectra contains two active ingredients: Afoxolaner and Milbemycin Oxime. They work synergistically to attack parasites in different ways, both externally and internally.
1. Hyper-Targeted Nervous System Attack on Fleas and Ticks
- How it Works: The ingredient Afoxolaner belongs to the isoxazoline class. It selectively binds to specific receptors in the nerve and muscle cells of invertebrates (like fleas and ticks), but not mammals. This blocks the passage of chloride ions, causing uncontrolled nervous system activity, paralysis, and death of the parasite.
- Result: Fleas and ticks are killed rapidly upon contact with the dog’s bloodstream.
2. Systemic Protection Through Blood Circulation
- How it Works: After your dog eats the tasty chew, similar to bravecto chewable for dogs, Afoxolaner is absorbed into their bloodstream and distributed throughout their body.
- Result: This creates a protective “shield” in the blood. When a flea or tick bites to take a blood meal, it ingests the active ingredient and is killed. The protection is internal and cannot be washed or rubbed off.
3. Rapid Speed of Kill to Prevent Feeding and Disease
- How it Works: Nexgard Spectra starts working quickly. It kills fleas within 8 hours and ticks (Black-legged tick, American Dog tick, and Brown Dog tick) within 48 hours.
- Result: This rapid action minimizes the chance for fleas to cause discomfort and lay eggs, and, crucially, reduces the window for ticks to transmit serious illnesses like Lyme disease or Anaplasmosis.
4. Breaking the Flea Life Cycle at the Source
- How it Works: By killing adult fleas before they can lay viable eggs, Nexgard Spectra acts as a “reproductive stop.” Since fleas are killed rapidly after jumping on the dog, they don’t get the chance to reproduce.
- Result: This breaks the life cycle (egg > larva > pupa > adult), helping to control and eliminate flea infestations in the dog’s environment.
5. Paralyzing and Eliminating Intestinal Worms
- How it Works: The second ingredient, Milbemycin Oxime, targets the nervous systems of intestinal parasites like roundworms and hookworms. It increases the permeability of their cell membranes to chloride ions, leading to paralysis and death of the worms.
- Result: Existing adult roundworms and hookworms are expelled from the dog’s gastrointestinal tract.
6. Preventing Heartworm Disease Proactively
- How it Works: Milbemycin Oxime is highly effective at eliminating the immature larval stages (L3 and L4) of the heartworm parasite, Dirofilaria immitis, that are transmitted by mosquitoes.
- Result: By killing these larvae before they can mature into adult worms that inhabit the heart and lungs, it provides continuous, monthly prevention of this potentially fatal disease.
7. Continuous Monthly Protection with Consistent Dosing
- How it Works: The formulation is designed to maintain effective levels of both active ingredients in the dog’s system for a full month. After 30 days, the concentration drops, signaling the need for the next dose to maintain uninterrupted protection.
- Result: A simple, once-a-month schedule ensures your dog is never left vulnerable to new infestations or infections.
8. Waterproof and Grooming-Proof Reliability
- How it Works: Because it’s a systemic chewable, its efficacy is not dependent on staying on the skin or coat. It works from the inside out.
- Result: Bathing, swimming, rain, or your dog’s grooming habits have no effect on its potency. The protection remains 100% effective all month long.
9. Palatable Delivery for Guaranteed Ingestion
- How it Works: The formulation is made into a soft, beef-flavored chew that most dogs readily accept as a treat.
- Result: This ensures that the dog consumes the full, precise dose, eliminating the mess, stress, and potential for incomplete application associated with topical treatments.
10. Comprehensive Multi-Parasite Defense in a Single Product
- How it Works: The combined power of Afoxolaner and Milbemycin Oxime creates a broad-spectrum defense that targets parasites at multiple points of contact—through the blood, in the gut, and at the larval stage.
- Result: This “all-in-one” approach protects against: Fleas, Ticks, Mites, Heartworm, Hookworm, and Roundworm. This consolidates what would often require 2 or 3 separate products into one simple monthly chew.
Summary Table: The Nexgard Spectra Shield
| Parasite | How Nexgard Spectra Works |
| Fleas | Kills adult fleas via nervous system overload before they can lay eggs. |
| Ticks | Kills ticks (Black-legged, American Dog, Brown Dog) through a bite, reducing disease risk. |
| Heartworm | Kills the immature larval stages transmitted by mosquitoes, preventing adult infection. |
| Roundworm | Paralyses and eliminates adult roundworms from the intestines. |
| Hookworm | Paralyses and eliminates adult hookworms from the intestines. |
Conclusion: Nexgard spectra for dogs works through a powerful, dual-pronged strategy. It uses a systemic insecticide to provide a constant internal shield against biting parasites, combined with a potent anthelmintic to prevent heartworm and treat intestinal worms. This integrated approach offers unparalleled convenience and comprehensive protection for dogs.
Important Disclaimer: Always consult your veterinarian before starting any new parasite prevention. Ensure your dog is tested for heartworm before beginning a preventative, as giving prevention to a heartworm-positive dog can cause complications. Use only the dose prescribed for your dog’s exact weight.
