NexGard Spectra for Dogs 66.1-132 lbs (30.1-60 kg)

Description

NexGard Spectra for Dogs 66.1–132 lbs (30.1–60 kg) is a monthly oral chewable from Boehringer Ingelheim containing 150 mg afoxolaner and 30 mg milbemycin oxime in a single 8 g tablet, formulated to deliver the minimum labeled therapeutic dose across the full weight band. This is the largest single-tablet variant in the NexGard Spectra range, providing concurrent coverage against fleas, ticks, mites, heartworm, and intestinal worms in one monthly administration. The tablet is indicated for dogs and puppies from 8 weeks of age whose body weight falls between 30.1 and 60 kg on the day of dosing.

Recommended for

Dogs weighing 66.1–132 lbs (30.1–60 kg) from 8 weeks of age.

Indication/Coverage

For dogs weighing 66.1–132 lbs (30.1–60 kg) suffer from, or at risk from, mixed parasitic infections:

• Flea treatment and prevention: Targets adult Ctenocephalides; afoxolaner, an isoxazoline-class compound, blocks GABA-gated chloride channels in invertebrate neurons, inducing fatal hyperexcitation in fleas within 6–8 hours of the dog ingesting the dose.
• Flea allergy dermatitis control: Sustained adult flea elimination across the monthly dosing interval prevents the salivary antigen accumulation that drives and perpetuates flea allergy dermatitis in sensitized large-breed dogs.
• Flea tapeworm prevention: Controls the Ctenocephalides vector responsible for transmitting Dipylidium caninum larvae; because infestation requires the dog to ingest an adult flea carrying tapeworm larvae, sustained flea kill on the animal severs the transmission route.
• Paralysis tick control: Treats and controls Ixodes holocyclus infestations for one full month; pre-existing Paralysis tick infestations are brought under control within 24 hours of administration.
• Brown Dog tick control: Treats and controls Rhipicephalus sanguineus to greater than 95% efficacy within 48 hours of the dog receiving the dose.
• Bush tick control: Treats and controls Haemaphysalis longicornis to greater than 95% efficacy within 48 hours.
• Demodectic mange treatment: Controls generalized demodectic mange caused by Demodex; monthly dosing should continue without interruption until two consecutive monthly skin scrapings confirm complete mite clearance.
• Sarcoptic mange treatment: Controls Sarcoptes scabiei with clinically significant resolution of skin lesions; two consecutive monthly treatments are required to complete the full treatment course.
• Ear mite treatment: A single dose achieves effective control of Otodectes cynotis infestations; persistent ear irritation after treatment requires veterinary evaluation to exclude secondary bacterial or yeast otitis.
• Heartworm prevention: Prevents Dirofilaria immitis by eliminating susceptible L3 and L4 larvae before they can mature into adult worms; uninterrupted monthly dosing is essential to close the exposure window between treatments.
• Roundworm treatment: Treats and controls Toxocara canis and Toxascaris leonina.
• Hookworm treatment: Treats and controls Ancylostoma caninum and Ancylostoma ceylanicum.
• Whipworm treatment: Treats and controls Trichuris vulpis.

Key Benefits

The properties below reflect labeled clinical data from Boehringer Ingelheim specific to the 30.1–60 kg variant and are stated on the basis of mechanism or documented efficacy, not general product claims.

• Large-breed single-tablet dosing: One 8 g chewable per month delivers the full labeled dose for dogs up to 60 kg without requiring a combination of smaller tablets, which reduces the risk of dosing error and incomplete ingestion that can arise when multiple units are administered.
• Coat-independent flea kill: Afoxolaner circulates systemically after ingestion and kills fleas upon feeding contact with the dog’s blood, independently of coat density, bathing frequency, or rain exposure; this is a pharmacokinetic distinction from topical residue-dependent products in large working or outdoor dogs.
• Fleas killed within 6–8 hours: Newly acquired adult fleas are eliminated before they can deposit viable eggs, preventing the environmental flea population from being continuously replenished by large dogs that carry a proportionally higher flea burden due to greater surface area.
• Greater than 95% tick efficacy within 24–48 hours: Paralysis ticks are controlled to greater than 95% within 24 hours; Brown Dog ticks and Bush ticks reach the same efficacy threshold within 48 hours, limiting the attachment duration during which tick-paralysis toxin or pathogens can be transmitted to dogs of this size.
• Dual-compound heartworm protection: Milbemycin oxime at 30 mg per tablet eliminates Dirofilaria immitis L3 and L4 larvae acquired in the preceding month; for large and giant-breed dogs with high cardiac risk from adult heartworm disease, maintaining an unbroken monthly schedule is particularly important.
• Eligible from 8 weeks of age: Dogs within this weight range from 8 weeks can begin comprehensive parasite protection immediately, covering the developmental window during which intestinal worm burdens are most clinically significant and heartworm larval exposure begins.
• No water restrictions post-dosing: Because NexGard Spectra acts through systemic distribution rather than surface residue, bathing, swimming, and shampooing at any point before or after the monthly dose do not affect circulating drug levels; this is practically relevant for large working breeds, water dogs, and those undergoing regular grooming or medicated baths.
• Collie-breed safety established: Boehringer Ingelheim confirmed NexGard Spectra was well tolerated in Collie breeds in clinical studies; dogs with documented MDR1 gene mutations or a prior history of drug-induced neurological events should be assessed by a veterinarian before the first dose, regardless of body weight.

Caution

Hazards to Humans

Accidental ingestion of afoxolaner poses a risk, particularly to children; remove the 8 g chewable from its blister packaging and administer it to the dog immediately without leaving it unattended. Keep all doses stored out of reach of children at all times. Wash hands after handling.

Hazards to Domestic Animals

NexGard Spectra is for oral administration in dogs only; do not use in cats or other species. This variant is indicated for dogs confirmed to weigh 30.1–60 kg from a minimum age of 8 weeks; do not administer to animals below this weight or age threshold. Dogs that are debilitated, aged, pregnant, or lactating require veterinary assessment before treatment commences. Afoxolaner belongs to the isoxazoline class; adverse reactions, while uncommon, include vomiting, diarrhea, lethargy, inappetence, pruritus, and rarely, seizures. Dogs receiving central nervous system-active drugs concurrently should be evaluated by a veterinarian before NexGard Spectra is initiated.

Possible Side Effects

Monitor your dog after each monthly administration, with heightened vigilance following the first dose and in any dog with a prior history of seizures, neurological conditions, or gastrointestinal sensitivity.

Adverse reactions to isoxazoline-class compounds are uncommon; the following events have been documented for NexGard Spectra across clinical and post-market experience:

• Gastrointestinal reactions: Vomiting, diarrhea, and inappetence have been reported following oral administration; these signs are generally self-limiting and resolve within 24–48 hours without requiring veterinary intervention.
• Pruritic reactions: Post-administration pruritus has been noted; itching that fails to resolve within 48 hours or that intensifies should be assessed by a veterinarian to distinguish a drug reaction from a concurrent dermatological condition.
• Systemic signs: Lethargy has been documented post-dosing; in large-breed dogs, persistent lethargy extending beyond 48 hours, or any concurrent neurological sign such as ataxia, muscle tremors, or altered mentation, requires prompt veterinary evaluation rather than observation at home.
• Seizures: Seizure activity is a rare but documented adverse event within the isoxazoline class; dogs with a pre-existing seizure disorder carry substantially elevated risk and must not receive this product without explicit prior veterinary clearance.