Dichlorophen
Dichlorophen is an anthelmintic agent used primarily as a cestocide (tapeworm treatment) in dogs and cats. It is effective against **Taenia** and **Dipylidium** species but is notably > **ineffective against Echinococcus**. Affected tapeworms are dislodged and disintegrate during their passage along the alimentary tract, meaning intact worms are rarely seen in the feces after treatment. **Clinical Pearl:** Dichlorophen is largely considered a legacy anthelmintic. In modern veterinary practice, it has been widely superseded by praziquantel, which offers a broader spectrum of activity (including *Echinococcus*) and a superior safety profile.
Mechanism: Dichlorophen acts by interfering with **oxidative phosphorylation** in the parasite → uncoupling of the electron transport chain → depletion of ATP (energy) reserves → paralysis, death, and subsequent disintegration of the tapeworm within the host's gastrointestinal tract.
Dosing by species
- Control of tapeworm infections (Taenia, Dipylidium) · 250 mg total dose (for cats <2.5 kg); 500 mg per 2.5 kg (for cats >2.5 kg) · PO · Single dose, repeat every 4-6 months · 1 day · Give maximum 6 tablets at one time; give the rest 3 hours later if no vomiting. Best administered immediately before the main feed. May be given whole or crushed in food.
- Control of tapeworm infections (Taenia, Dipylidium) · 250 mg total dose (for dogs <2.5 kg); 500 mg per 2.5 kg (for dogs >2.5 kg) · PO · Single dose, repeat every 4-6 months · 1 day · Give maximum 6 tablets at one time; give the rest 3 hours later if no vomiting. Best administered immediately before the main feed. May be given whole or crushed in food.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Animals weighing < 1.25 kg
- Animals < 6 months of age
- Repeating treatment within 10 days
- Repeating treatment immediately if vomiting occurs shortly after dosing
Adverse effects
- Vomiting
- Salivation (rare)
- Hyperaesthesia (rare)
- Loss of coordination/ataxia (rare)
Monitoring
- Resolution of tapeworm segments (proglottids) in feces or around the perineum
- Vomiting post-administration
- Neurological signs (ataxia, hyperaesthesia) in sensitive individuals
Overdose
Overdosage may lead to gastrointestinal distress (severe vomiting) and neurological signs including hypersalivation, hyperaesthesia, and loss of coordination (ataxia). Treatment is supportive and symptomatic.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.