Niclosamide: veterinary dose and monograph

At a glance

Drug class

Antiparasitic

Also known as

Lintex, Yomesan, Niclosamide

Species with doses

Dogs, Cats, Cattle, Goats, Sheep and Birds

General dose range

100–157 mg/kg PO single dose (repeat in 2–3 weeks) — check the species tables for the indication

Routes

PO

Last reviewed

1 October 2026

Indications

• Tapeworm (cestode) infections — Taenia, Moniezia (ruminants), Dipylidium, etc.
• Deworming of dogs, cats, ruminants and poultry for susceptible cestodes
• Molluscicide for snail control in fluke-endemic pastures (environmental use)

Niclosamide dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Tapeworms: Product-label dose — neither Papich 5e nor Plumb’s has a niclosamide monograph. Give after a light fast; repeat in 2–3 weeks. Praziquantel is preferred (and required for Echinococcus).

Cats

• Tapeworms: Label-sourced — neither Papich 5e nor Plumb’s has a niclosamide monograph. Give after a light fast. Praziquantel is preferred (and required for Echinococcus).

Cattle

• Moniezia / cestodes: Label-sourced — neither Papich 5e nor Plumb’s has a niclosamide monograph (Merck lists it among ruminant salicylanilides without a dose). Poorly absorbed (gut-local). Follow the local label withdrawal.

Goats

• Tapeworms (Moniezia): Product-label dose — neither Papich 5e nor Plumb’s has a niclosamide monograph. Poorly absorbed (gut-local). Follow the local label withdrawal.

Sheep

• Moniezia (lambs): Label-sourced — neither Papich 5e nor Plumb’s has a niclosamide monograph. Poorly absorbed (gut-local). Follow the local label withdrawal.

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Moniezia / cestodes: Label-sourced — neither Papich 5e nor Plumb’s has a niclosamide monograph (Merck lists it among ruminant salicylanilides without a dose). Poorly absorbed (gut-local). Follow the local label withdrawal.

Birds

• Tapeworms (poultry): Label-sourced — neither Papich 5e nor Plumb’s has a niclosamide monograph; Merck describes it as experimental in poultry and not approved in the USA. Follow the local product label, including egg and meat withdrawal.

Contraindications

Known hypersensitivity. Less effective against Echinococcus and Dipylidium than praziquantel — choose praziquantel when those are the target. Ensure correct parasite identification.

Species-specific warnings

Dogs: For Echinococcus (zoonotic hydatid) control, use praziquantel — niclosamide is less reliable against this important tapeworm.

Adverse effects

• Mild, transient GI upset (vomiting, soft stool)
• Generally minimal due to negligible absorption

Drug interactions

• No clinically important systemic drug interactions (negligible absorption)
• Alcohol may enhance absorption (avoid in formulations where relevant)

Pregnancy and lactation

Wide margin and minimal absorption make it acceptable in pregnancy/lactation at deworming doses.

Monitoring

• Faecal exam / proglottid passage for cure; repeat dose at 2–3 weeks
• Concurrent flea control when treating Dipylidium (flea is the vector)
• Correct cestode identification (use praziquantel for Echinococcus/Dipylidium)

Toxicity and overdose

Very low systemic toxicity owing to poor absorption; overdose typically causes only GI upset. Environmental caution: as a molluscicide it is toxic to fish and aquatic invertebrates — keep out of waterways.

Management: Supportive only — fluids and anti-emetic if needed. No specific antidote required given the wide margin.

Clinical pearls

• Safe and cheap tapeworm drug — but praziquantel is superior for Dipylidium and the zoonotic Echinococcus
• It may leave the scolex intact — repeat dosing and breaking the flea/intermediate-host cycle prevent reinfection
• A brief fast before dosing can improve contact with the worm
• Doubles as a pasture/snail molluscicide in liver-fluke control programmes — but it is toxic to fish, so protect waterways

Mechanism of action

Uncouples oxidative phosphorylation in the tapeworm and inhibits anaerobic ATP generation (glucose uptake), destroying the worm's energy supply. The damaged scolex and proximal segments detach from the gut wall and are expelled. Poor host absorption confines the action to the gut lumen.

Formulations and products

• 500 mg tablet (chewable)
• Oral powder / suspension
• Niclosamide vet tablets (Various (India)) — 500 mg, Oral tablet
• Niclosamide (Yomesan) — 500 mg chewable tablet, Chewable tablet (human-label)

Storage

Tablets/powder: 15–30 °C, dry, protected from light. Molluscicide formulations: store and dispose away from water bodies.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Other antiparasitics

• Monepantel
• Morantel
• Moxidectin
• Nicarbazin
• Nitenpyram
• Nitroxynil
• Oxfendazole
• Oxibendazole

Frequently asked questions