NexGard Spectra for Dogs 33.1-66 lbs (15.1-30 kg)

Description

NexGard Spectra for Dogs 33.1–66 lbs (15.1–30 kg) combines 75 mg afoxolaner and 15 mg milbemycin oxime in a single 4 g monthly oral chewable, manufactured by Boehringer Ingelheim to meet the minimum labeled dose across the full weight band. One tablet per month covers fleas, ticks, mites, heartworm, and intestinal worms without requiring separate products for individual parasite categories. This variant is indicated for dogs and puppies from 8 weeks of age whose body weight falls between 15.1 and 30 kg on the day of administration.

Recommended for

Dogs weighing 33.1–66 lbs (15.1–30 kg) from 8 weeks of age.

Indication/Coverage

For dogs weighing 33.1–66 lbs (15.1–30 kg) suffer from, or at risk from, mixed parasitic infections:

• Flea treatment and prevention: Targets adult Ctenocephalides; afoxolaner selectively inhibits GABA-gated chloride channels in invertebrate neurons, generating uncontrolled neural excitation that kills fleas within 6–8 hours of the dog ingesting the dose.
• Flea allergy dermatitis control: Sustained adult flea kill limits repeated salivary antigen deposition on sensitized skin; monthly dosing prevents the antigen accumulation that perpetuates or intensifies dermatitis flare cycles in affected dogs.
• Flea tapeworm prevention: Eliminates the Ctenocephalides vector through which Dipylidium caninum larvae are transmitted; because dogs acquire tapeworm by swallowing infected adult fleas, sustained flea suppression on the animal disrupts the transmission route entirely.
• Paralysis tick control: Treats and controls Ixodes holocyclus infestations for one full 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 of administration.
• 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 continue until the absence of mites is confirmed by two consecutive negative monthly skin scrapings.
• Sarcoptic mange treatment: Controls Sarcoptes scabiei with clinically significant improvement in skin lesions; two consecutive monthly doses constitute the complete treatment course.
• Ear mite treatment: A single dose achieves effective control of Otodectes cynotis infestations; ear irritation persisting after treatment warrants veterinary evaluation to exclude secondary otitis.
• Heartworm prevention: Prevents Dirofilaria immitis by eliminating L3 and L4 larvae before they can develop into adult worms; continuous monthly administration without interruption is required to maintain this protection.
• 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 following characteristics are drawn from Boehringer Ingelheim’s labeled clinical data for the 15.1–30 kg variant and reflect mechanism or efficacy distinctions specific to this weight band.

• Full-spectrum single dose: One 4 g chewable per month addresses ectoparasites and endoparasites concurrently, eliminating the scheduling complexity that arises when flea, tick, worming, and heartworm products are managed separately across a 30-day cycle.
• Systemic flea elimination: Afoxolaner distributes through the bloodstream and kills fleas upon feeding contact with the dog’s circulation; coat thickness, bathing frequency, and swimming do not diminish flea kill efficacy, unlike topical residue-dependent products.
• Rapid flea kill onset: Fleas are eliminated within 6–8 hours of administration, preventing newly acquired adults from depositing viable eggs and interrupting the cycle by which environmental flea stages are continuously replenished.
• Greater than 95% tick kill within 48 hours: Paralysis ticks, Brown Dog ticks, and Bush ticks are reduced to less than 5% survival within 24–48 hours, narrowing the window during which tick attachment can result in toxin injection or disease transmission in the 15.1–30 kg size range.
• Larval-stage heartworm interception: Milbemycin oxime at 15 mg per tablet eliminates Dirofilaria immitis at the L3 and L4 larval stages; dosing on the same calendar date each month ensures larvae acquired in the preceding interval are cleared before they advance past the susceptible developmental window.
• Eligible from 8 weeks of age: Dogs within this weight range from 8 weeks can begin full-spectrum parasite protection immediately, covering the developmental period during which intestinal worm acquisition and heartworm larval exposure present the greatest clinical risk.
• Oral route for coat-incompatible dogs: Dogs with dense double coats, skin sensitivity to topical formulations, or a behavioral aversion to spot-on application receive equivalent parasite coverage through the oral chewable route without any contact-application variable.
• Collie-breed tolerance confirmed: Boehringer Ingelheim’s safety studies confirmed NexGard Spectra was well tolerated in Collie breeds; dogs with documented MDR1 mutations or a history of drug-induced neurological events should nonetheless be assessed by a veterinarian before commencing treatment.

Caution

Hazards to Humans

Accidental ingestion of afoxolaner presents a risk, particularly to children; remove the 4 g chewable from its blister packaging and administer it to the dog without delay, without leaving the dose unattended. Store all remaining doses out of reach of children. Wash hands after handling.

Hazards to Domestic Animals

NexGard Spectra is for oral use in dogs only; do not administer to cats or other species. This variant is indicated for dogs confirmed to weigh 15.1–30 kg from a minimum age of 8 weeks; administering this tablet to animals below this weight or age threshold falls outside labeled use. Dogs that are debilitated, aged, pregnant, or lactating require veterinary assessment before treatment is initiated. Afoxolaner is an isoxazoline-class compound; adverse reactions are uncommon but include vomiting, diarrhea, lethargy, inappetence, pruritus, and, rarely, seizures. Consult a veterinarian before co-administering NexGard Spectra with any drug affecting the central nervous system.

Possible Side Effects

Monitor your dog after each monthly administration, with particular care following the first dose and in any dog with a documented history of neurological or gastrointestinal sensitivity.

Adverse reactions to isoxazoline-class compounds are uncommon; the following events have been reported for NexGard Spectra:

• Gastrointestinal reactions: Vomiting, diarrhea, and inappetence have been documented following oral administration; these signs are generally self-limiting and resolve within 24–48 hours without requiring clinical intervention.
• Pruritic reactions: Post-administration pruritus has been reported; itching that intensifies or fails to resolve within 48 hours should be assessed by a veterinarian to determine whether it represents a drug reaction or an underlying dermatological condition.
• Systemic signs: Lethargy has been noted following dosing; persistent lethargy beyond 48 hours, or any neurological sign including ataxia, muscle tremors, or disorientation, warrants prompt veterinary evaluation rather than a wait-and-see approach.
• Seizures: Seizure activity is a rare but documented adverse event across the isoxazoline class; dogs with a prior seizure history face substantially elevated risk and must not receive NexGard Spectra without prior veterinary clearance.