Cat Dewormer Dosage Calculator — Pyrantel, Praziquantel & Fenbendazole
How much pyrantel, praziquantel, or fenbendazole does your cat actually need? This calculator computes the per-weight dose for each of the three over-the-counter cat dewormers (and one selamectin spot-on option), citing Plumb’s Veterinary Drug Handbook and the Companion Animal Parasite Council feline guidelines. Always confirm with your veterinarian before dosing kittens or sick cats.
Calculator
Targets
Roundworms, hookworms
Safe from 4 weeks of age. 20 mg/kg (cat dose is higher than dog).
Pyrantel vs praziquantel vs fenbendazole: which dewormer for which worm?
| Drug | Target parasites | Cat dose | Schedule |
|---|---|---|---|
| Pyrantel pamoate | Roundworms, hookworms | 20 mg/kg PO | Repeat in 2-3 weeks |
| Praziquantel | Tapeworms (incl. Dipylidium) | 5 mg/kg PO or SC | Single dose |
| Fenbendazole | Round, hook, tape, Giardia | 50 mg/kg PO × 3 days | Repeat at 3 weeks if needed |
| Selamectin (Revolution) | Round, hook, fleas, ear mites, heartworm | Topical, weight-banded | Monthly |
Feline deworming terminology
- Anthelmintic
- Drug class that kills or expels parasitic worms. Pyrantel, praziquantel and fenbendazole are all anthelmintics.
- PO (per os)
- Latin for "by mouth" — the route most cat dewormers use.
- Patent infection
- Worm burden that has matured enough to shed eggs detectable on a fecal test. Repeat dosing in 2-3 weeks catches the next maturation cycle.
Frequently Asked Questions
What dewormer is safe for cats?
Pyrantel pamoate (Nemex) for roundworms/hookworms — safe from 4 weeks age. Praziquantel (Droncit) for tapeworms. Fenbendazole (off-label but widely accepted) for broader coverage. Selamectin (Revolution) monthly topical for most parasites + fleas.
How much dewormer should I give my cat?
Pyrantel: 20 mg/kg single dose (cat dose is higher than dog at 5-10 mg/kg). Praziquantel: 5 mg/kg. Fenbendazole: 50 mg/kg daily × 3 days. Always repeat pyrantel in 2-3 weeks.
How often should I deworm my cat?
Kittens: every 2 weeks from 2-8 weeks, then monthly to 6 months. Adults: every 3-6 months, or based on fecal exam positive. Outdoor/hunting cats: every 1-3 months.
Sources & References
- [1]Plumb's Veterinary Drug Handbook — Plumb's Veterinary Drugs
- [2]CAPC Feline Parasite Control Guidelines — Companion Animal Parasite Council
- [3]
Common mistakes to avoid
- Using dog dewormer on cats — some dog dewormers (permethrin-based) are LETHAL to cats.
- Single-dose assumption — most parasites need a re-dose in 2-3 weeks to catch hatched larvae.
- Skipping fecal exam — empiric deworming misses tapeworms, whipworms, protozoa (Giardia, coccidia).
When to call the vet immediately
- Pale gums, bloody diarrhea, weakness — heavy parasite load, emergency.
- Worms in vomit or stool — confirm type with a fecal (tapeworm vs roundworm need different meds).
Pro tips
- Indoor-only cats: fecal check annually. Outdoor cats: every 6 months.
- Monthly flea preventive (Revolution Plus, Bravecto) often covers some common worms too.
- Pregnant queens should be dewormed per vet plan to prevent transmission to kittens.
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