Skip to main content
FurCalc

Dog Dewormer Dosage Calculator — Fenbendazole, Pyrantel & Praziquantel

How much fenbendazole, pyrantel, praziquantel or ivermectin does your pup need by weight? This calculator computes the per-kg dose for the four most common canine anthelmintics, with doses sourced from Plumb’s Veterinary Drug Handbook and cross-checked against the Companion Animal Parasite Council canine guidelines. Always confirm with your veterinarian — especially for Collie-related breeds with potential MDR1 sensitivity to ivermectin.

Calculator

Enter inputs to enable Save / Email
Fenbendazole
1,020.6mg / dose
Once daily · 3 consecutive days (5 days for Giardia)

Targets

Roundworms, hookworms, whipworms, tapeworms (Taenia), Giardia

One of the safest dewormers. Safe for puppies 6+ weeks and pregnant dogs.

Fenbendazole vs pyrantel vs praziquantel vs ivermectin: which dewormer for which parasite?

DrugTarget parasitesDog doseCaution
Fenbendazole (Panacur)Round, hook, whip, tapeworm (Taenia), Giardia50 mg/kg PO × 3 daysSafe in pregnancy
Pyrantel pamoateRound, hook5-10 mg/kg PO, repeat 2 wkVery wide safety margin
PraziquantelTapeworms (incl. Dipylidium, Echinococcus)5 mg/kg single dosePair with flea control
IvermectinHeartworm (low dose) + some intestinal6-12 µg/kg (HW prevention)Collie / MDR1 — genetic test first

Canine deworming terminology

MDR1 mutation
A genetic variant in Collies, Australian Shepherds and related breeds that causes severe ivermectin toxicity at standard doses.
Fecal float
Diagnostic test that floats parasite eggs from a stool sample; used to identify which dewormer to choose.
Patent infection
Mature worm burden that is shedding eggs detectable on fecal exam. Repeat dose at 2-3 weeks catches the next maturation wave.

Frequently Asked Questions

What dewormer is safe for my dog?

Fenbendazole (Panacur, Safe-Guard) is one of the safest — approved for puppies 6+ weeks and pregnant dogs. Pyrantel pamoate (Nemex) is the standard puppy dewormer from 2 weeks of age. Praziquantel (Droncit) treats tapeworms.

How much fenbendazole do I give my dog?

50 mg per kg (22.7 mg per lb) once daily for 3 consecutive days. For Giardia, extend to 5 days. A 20 kg dog = 1,000 mg per day, typically 10 mL of 10 % oral suspension.

What is the pyrantel dose for dogs?

5–10 mg per kg as a single dose, repeated in 2–3 weeks. A 10 kg puppy gets 50–100 mg.

What is the MDR1 mutation and which breeds are affected?

MDR1 (multi-drug resistance 1) is a gene mutation that makes certain drugs — especially ivermectin at high doses — toxic. Collies, Australian Shepherds, Shelties, Old English Sheepdogs, Silken Windhounds, Whippets (long-haired) and mixes with these breeds should be genetically tested before high-dose ivermectin.

How often should I deworm my dog?

Adult dogs: fecal exam 1–2× per year; treat only if positive. Puppies: deworm every 2 weeks from 2 weeks to 12 weeks, then monthly until 6 months. Adults on monthly heartworm preventive (Heartgard) get roundworm/hookworm coverage.

Can I deworm a pregnant dog?

Yes — fenbendazole is safe throughout pregnancy. Deworm the dam at 40 days of gestation and weekly from day 40 until 2 days post-whelping to prevent roundworm transmission to puppies.

Can I give my dog human dewormers?

No. Human dewormers use different formulations and dosages. Always use products labeled for dogs and dosed by weight.

Sources & References

  1. [1]
    Plumb's Veterinary Drug Handbook — Plumb's Veterinary Drugs
  2. [2]
    CAPC — Companion Animal Parasite Council Guidelines — Companion Animal Parasite Council
  3. [3]