NexGard is a global veterinary brand of parasite-control medications for companion animals, primarily dogs and, more recently, cats. The brand is best known for its monthly flea and tick treatments and has expanded into a family of products that also protect against heartworms and intestinal parasites. NexGard is marketed by Boehringer Ingelheim Animal Health, one of the world’s largest animal health companies. [1]

NexGard became one of the first oral isoxazoline flea-and-tick medications for dogs and is now one of the best-selling veterinary parasite-control brands worldwide. [2]

NexGard was developed following research into the isoxazoline class of antiparasitic compounds, which selectively target the nervous systems of fleas and ticks.

The original NexGard chewable tablet, containing afoxolaner, was launched around 2013–2014. Its flavored chewable format offered an alternative to topical “spot-on” flea treatments.

Following its commercial success, the brand expanded into several combination products that protect against additional parasites beyond fleas and ticks. [3]

NexGard

Active ingredient

• Afoxolaner

Species

• Dogs

Protects against

• Fleas

• Multiple tick species

Administration

• Monthly beef-flavored chewable tablet

This is the original NexGard product and remains one of the most widely prescribed oral flea-and-tick medications for dogs. [4]

NexGard PLUS

Active ingredients

• Afoxolaner

• Moxidectin

• Pyrantel

Species

• Dogs

Protects against

• Fleas

• Ticks

• Heartworm disease

• Roundworms

• Hookworms

NexGard PLUS combines flea-and-tick protection with prevention and treatment for several internal parasites, providing broad monthly parasite control in a single chew. [5]

NexGard SPECTRA

Active ingredients

• Afoxolaner

• Milbemycin oxime

Species

• Dogs

Protects against

• Fleas

• Ticks

• Heartworm

• Lungworms (market-dependent)

• Roundworms

• Hookworms

• Whipworms

• Certain mites

NexGard SPECTRA is widely available outside the United States and is considered one of the company’s flagship canine parasite products. [6]

NexGard COMBO

Active ingredients

• Esafoxolaner

• Eprinomectin

• Praziquantel

Species

• Cats

Protects against

• Fleas

• Ticks

• Heartworms

• Roundworms

• Hookworms

• Tapeworms

Unlike the canine products, NexGard COMBO is a topical monthly treatment applied to the skin. [7]

The main ingredient in the original NexGard, afoxolaner, belongs to the isoxazoline family of antiparasitic drugs.

After administration:

1. The medication is absorbed into the dog’s bloodstream.

2. Fleas and ticks ingest the drug while feeding.

3. The drug disrupts parasite nerve signaling by blocking ligand-gated chloride channels.

4. The parasites become paralyzed and die.

Because the medication works systemically, it does not need to coat the animal’s skin or fur. [8]

Depending on the specific NexGard product, it may be indicated for:

• Treatment and prevention of flea infestations

• Treatment and control of tick infestations

• Prevention of Lyme disease by killing infected black-legged ticks (certain markets/products)

• Prevention of heartworm disease

• Treatment and control of intestinal worms

• Treatment of tapeworms (cat formulations)

Approved uses vary by country and veterinary regulatory authority. [9]

Veterinarians commonly recommend NexGard because it offers:

• Monthly protection

• Oral administration (for canine chew products)

• No greasy residue compared with topical treatments

• Activity against multiple tick species

• Rapid flea killing before egg laying

• Palatable beef-flavored chewables for dogs

• Combination formulations that reduce the number of separate medications needed [10]

Like all veterinary medicines, NexGard should be used according to veterinary guidance and product labeling.

Commonly reported adverse effects include:

• Vomiting

• Diarrhea

• Reduced appetite

• Lethargy

• Itching (pruritus)

Because isoxazolines can affect the nervous system, products in this class should be used with caution in animals with a history of seizures or neurologic disorders. [11]

NexGard products are sold in many countries across:

• North America

• Europe

• Asia

• Australia

• Latin America

• Africa

The exact product lineup differs by market. For example:

• NexGard SPECTRA is widely available internationally.

• NexGard PLUS is marketed in the United States.

• NexGard COMBO is available for cats in several regions. [12]

NexGard products are approved by veterinary regulatory authorities in many countries. Approval requirements, labeled indications, and availability vary by jurisdiction. In the United States, individual products are regulated by the U.S. Food and Drug Administration (FDA) through the animal drug approval process. [13]

NexGard is one of the leading brands in the global companion animal parasiticide market. According to Boehringer Ingelheim’s 2023 annual report, the NexGard brand family is its best-selling pet medication brand and a cornerstone of its parasite-control portfolio. [14]

• Boehringer Ingelheim Animal Health

• Isoxazoline antiparasitic drugs

• Flea control in dogs and cats

• Tick-borne diseases

• Heartworm disease

• Veterinary parasiticides

1. Boehringer Ingelheim — Annual Report 2023

2. NexGard® (afoxolaner) Canine Flea and Tick Protection

3. NexGard® PLUS All-In-One Parasiticide for Dogs | Boehringer Ingelheim

4. NexGard® COMBO Broad-Spectrum Parasiticide for Cats | Boehringer Ingelheim

5. Looking for Prescribing Information?

6. NexGard® (afoxolaner) Chewables

7. DailyMed – NEXGARD- afoxolaner tablet, chewable

8. NexGard® (afoxolaner) Chewables

9. FDA Verification Portal

10. DailyMed – NEXGARD- afoxolaner tablet, chewable

11. FDA Verification Portal

12. FDA Verification Portal

13. NexGard® PLUS All-In-One Parasiticide for Dogs | Boehringer Ingelheim

14. Canine Parasiticides | Boehringer Ingelheim Animal Health