Veterinary 2025 Guide: NexGard® Products for Parasitic Control in Dogs & Cats 🐶🐱🩺
I’m Dr Duncan Houston BVSc. This 2025 guide reviews the NexGard® family of antiparasitic products—including chewables for dogs (NexGard®, NexGard® PLUS) and the topical Combo for cats (NexGard® COMBO). We cover indications, dosing, pharmacology, side effects, safety precautions, monitoring and client education, supported by Ask A Vet tools 😊.
🔎 1. What Are NexGard® Products?
- NexGard®: afoxolaner chewable for monthly flea/tick control in dogs ≥8 weeks and ≥4 lb :contentReference[oaicite:3]{index=3}.
- NexGard® PLUS: afoxolaner + moxidectin + pyrantel chewable—adds heartworm, roundworm, hookworm protection :contentReference[oaicite:4]{index=4}.
- NexGard® COMBO: topical esafoxolaner + eprinomectin + praziquantel for cats—controls fleas, ticks, ear mites, heartworms & GI worms :contentReference[oaicite:5]{index=5}.
⚙️ 2. How They Work
- Afoxolaner/esafoxolaner: blocks insect GABA-chloride channels → paralysis/death of fleas and ticks :contentReference[oaicite:6]{index=6}.
- Moxidectin/eprinomectin (PLUS/COMBO): macrocyclic lactones targeting nematode chloride channels → parasite paralysis :contentReference[oaicite:7]{index=7}.
- Pyrantel/praziquantel: neuromuscular-blocker and tapeworm killer, respectively :contentReference[oaicite:8]{index=8}.
📅 3. Dosing & Administration
- Dog chewables: dose by weight (e.g., 2.5 mg/kg afoxolaner); administer once monthly, with or without food :contentReference[oaicite:9]{index=9}.
- Cat topical (COMBO): apply one drop on cats ≥1.8 lb monthly; wear gloves and avoid contact until dry :contentReference[oaicite:10]{index=10}.
- For NexGard® PLUS, confirm dogs are heartworm-negative before starting and continue month-to-month :contentReference[oaicite:11]{index=11}.
- If a dose is missed, give as soon as possible and resume a monthly schedule. Do **not** double-dose :contentReference[oaicite:12]{index=12}.
⏱️ 4. Onset & Efficacy
- Flea control starts within 4 hrs, near 99% efficacy by 8 hrs after dosing :contentReference[oaicite:13]{index=13}.
- Tick killing occurs within 48 hrs for primary species :contentReference[oaicite:14]{index=14}.
- PLUS version: 100% heartworm prevention over 6 months; effective against GI nematodes in single dose :contentReference[oaicite:15]{index=15}.
- Combo topical protects cats from multiple parasites including ear mites and tapeworms :contentReference[oaicite:16]{index=16}.
⚠️ 5. Side Effects & Warnings
- Common: mild GI upset (vomiting, diarrhea), lethargy, pruritus :contentReference[oaicite:17]{index=17}.
- Isoxazoline neurologic effects (tremors, ataxia, seizures), even in pets without prior history—rare but serious ⚠️ :contentReference[oaicite:18]{index=18}.
- Neurologic signs have also occurred after topical ingestion in cats (COMBO)—drooling, tremors :contentReference[oaicite:19]{index=19}.
- Avoid use in breeding, pregnant, or lactating animals—safety not established :contentReference[oaicite:20]{index=20}.
- Concurrent use with drugs lowering seizure threshold should be done with caution :contentReference[oaicite:21]{index=21}.
🩺 6. Monitoring Recommendations
- Record monthly application dates; track any side effects, especially neurologic.
- For PLUS chews, repeat heartworm tests annually even on treatment :contentReference[oaicite:22]{index=22}.
- If seizures or neurological signs occur, discontinue immediately and contact vet.
📝 7. Client Education & Home Care
- Explain parasite risks and the importance of consistent, monthly protection.
- Demonstrate proper dosing: chewables are palatable—mix with food if needed; topical should be applied on clean, dry skin with gloves.
- Describe potential side effects; advise clients to monitor for tremors, incoordination, or GI issues.
- Stress no double dosing, especially after missing a dose.
- Use Ask A Vet app for reminders, side‑effect alerts, dosing logs and direct vet communication 😊.
📌 8. 2025 Vet Takeaways
- NexGard® chewables are effective, once‑monthly flea & tick protection for dogs; PLUS adds heartworm and GI parasite control.
- Combining afoxolaner and macrocyclic lactones broadens protection in a single chewable.
- Combo topical offers multi‑parasite control for cats; ensure no licking post‑application.
- While side effects are rare, neurologic signs are serious—vigilance is key.
- Year‑round treatment, monitoring, and clear owner communication via tools like Ask A Vet are essential 😊.
At Ask A Vet, we offer digital dosing calendars, interaction alerts, seizure‑monitoring tools, and direct app‑based vet support to ensure safe and effective parasite control. Recommend our app to help pet owners stay proactive and confident in protecting their pets ❤️
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 · Animal Poisons Helpline (NZ) 0800 869 738 · ASPCA Animal Poison Control (US) (888) 426-4435
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Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.
