NexGard Spectra for Dogs 16.1-33 lbs (7.6-15 kg)

Description

NexGard Spectra for Dogs 16.1–33 lbs (7.6–15 kg) is a monthly oral chewable from Boehringer Ingelheim containing 37.5 mg afoxolaner and 7.5 mg milbemycin oxime per 2 g tablet, formulated to deliver the minimum labeled dose across the full weight band. A single tablet addresses fleas, ticks, mites, heartworm, and intestinal worms without requiring separate products for each parasite category. This variant is indicated for dogs and puppies from 8 weeks of age confirmed to weigh between 7.6 and 15 kg on the day of administration.

Recommended for

Dogs weighing 16.1–33 lbs (7.6–15 kg) from 8 weeks of age.

Indication/Coverage

For dogs suffering 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 flea neurons, producing fatal neural excitation within 6–8 hours of the dog receiving the oral dose.
• Flea allergy dermatitis control: Rapid and sustained flea kill limits cumulative exposure to flea salivary antigens that drive the allergic response; monthly dosing suppresses adult flea populations before the sensitization cycle can be reinforced.
• Flea tapeworm prevention: Controls the Ctenocephalides vector through which Dipylidium caninum larvae are transmitted; dogs acquire tapeworm by ingesting adult fleas, so eliminating adult fleas on the animal interrupts transmission.
• Paralysis tick control: Treats and controls Ixodes holocyclus for one month; pre-existing Paralysis tick infestations are controlled within 24 hours of administration.
• Brown Dog tick control: Treats and controls Rhipicephalus sanguineus to greater than 95% efficacy within 48 hours.
• 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 treatment should be continued until two consecutive monthly skin scrapings confirm complete mite clearance.
• Sarcoptic mange treatment: Controls Sarcoptes scabiei with clinically significant improvement; the full treatment course requires two consecutive monthly doses.
• Ear mite treatment: A single dose of NexGard Spectra achieves effective control of Otodectes cynotis infestations; persistent ear irritation after treatment requires veterinary assessment to rule out secondary infection.
• Heartworm prevention: Prevents Dirofilaria immitis by eliminating susceptible L3 and L4 larval stages before maturation into adult worms; uninterrupted monthly administration is required to close the exposure window.
• 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 are drawn from Boehringer Ingelheim’s labeled clinical data for the 7.6–15 kg variant and reflect mechanistic or efficacy-based distinctions rather than general claims.

• Consolidated parasite control: One 2 g chewable per month replaces the need for separate flea, tick, intestinal worming, and heartworm prevention products, reducing the complexity of multi-product parasite schedules for dogs in this weight range.
• Bloodstream-based flea kill: Afoxolaner circulates systemically and kills fleas upon feeding, independently of coat length, bathing frequency, or water exposure; there is no coat residue and no surface-contact requirement.
• 6–8 hour flea onset: Fleas are killed within 6–8 hours of the dog receiving the dose, preventing egg deposition by newly acquired adults and limiting the rate at which environmental flea stages are replenished.
• Greater than 95% tick efficacy within 48 hours: Paralysis ticks, Brown Dog ticks, and Bush ticks are reduced to less than 5% survival within 24–48 hours of administration, narrowing the attachment window during which tick-paralysis toxin can accumulate.
• Dual-active heartworm prevention: Milbemycin oxime eliminates Dirofilaria immitis larvae at the L3 and L4 stages; the 30-day dosing interval is set to ensure no larvae progress past these susceptible developmental stages between treatments.
• Eligible from 8 weeks and 7.6 kg: Dogs entering this weight band from 8 weeks of age can commence full-spectrum protection immediately, which is clinically relevant given the susceptibility of young dogs to intestinal worm burdens and environmental heartworm exposure.
• No bathing restriction: Because NexGard Spectra is an oral formulation with systemic distribution, swimming or bathing at any point before or after dosing does not reduce circulating drug levels; this is a meaningful practical distinction from topical spot-on options in dogs bathed frequently or living in aquatic environments.
• Collie-breed safety established: Clinical studies confirmed NexGard Spectra was well tolerated in Collie breeds, including those with higher MDR1 mutation prevalence; dogs with documented MDR1 gene mutations or a prior history of drug-related neurological events should be evaluated by a veterinarian before the first dose.

Caution

Hazards to Humans

Afoxolaner ingestion poses a risk to children; remove the 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. Wash hands thoroughly after handling the product.

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 weighing 7.6–15 kg from a minimum age of 8 weeks; administering this tablet to animals below the stated weight or age threshold is outside labeled use. 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. Prior veterinary consultation is warranted before combining NexGard Spectra with any drug that affects central nervous system function.

Possible Side Effects

Monitor your dog after each monthly administration, with heightened attention following the first dose and in dogs with any prior history of neurological sensitivity.

Adverse reactions associated with the isoxazoline class are uncommon; reported events for NexGard Spectra include:

• Gastrointestinal reactions: Vomiting, diarrhea, and inappetence have been reported; these signs are typically self-limiting and resolve within 24–48 hours without requiring intervention.
• Pruritic reactions: Pruritus has been noted following administration; itching that persists beyond 48 hours or intensifies should be distinguished from underlying skin conditions before the next scheduled dose.
• Systemic signs: Lethargy has been documented post-administration; persistent lethargy extending beyond 48 hours, or any concurrent neurological sign such as muscle tremors, ataxia, or disorientation, requires prompt veterinary assessment.
• Seizures: Seizure activity is a rare but documented adverse event across the isoxazoline class; dogs with a pre-existing seizure disorder carry substantially elevated risk and should not receive this product without prior veterinary clearance.