Piperazine
Diethylenediamine
Also known as: Pipa-Tabs · Wazine · WormEze · D-Worm · Tasty Paste · Various AVM-GSL products · Diethylendiamin · Dispermin · Hexahydropropyrazin · Piperazinum · Piperazina
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Treatment of ascarids | 45-65 mg of base/kg PO; for pups less than 2.5 kg: 150 mg maximum | PO | once | Retreat in 2-3 weeks | 🌎 NA |
| Treatment of ascarids | 110 mg/kg PO | PO | once | Repeat in 21 days | 🌎 NA |
| Treatment of ascarids | 100 mg/kg PO | PO | once | Repeat in 3 weeks | 🌎 NA |
| Treatment of ascarids | 20-30 mg/kg PO once | PO | once | — | 🌎 NA |
- Treatment of ascarids: Larval stages in tissues are not affected, necessitating retreatment
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Treatment of ascarids | 45-65 mg of base/kg PO; 150 mg maximum | PO | once | Retreat in 2-3 weeks | 🌎 NA |
| Treatment of ascarids | 110 mg/kg PO | PO | once | Repeat in 21 days | 🌎 NA |
| Treatment of ascarids | 100 mg/kg PO | PO | once | Repeat in 3 weeks | 🌎 NA |
| Treatment of ascarids | 20-30 mg/kg PO once | PO | once | — | 🌎 NA |
- Treatment of ascarids: Larval stages in tissues are not affected, necessitating retreatment
Small Mammals
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Pinworms (Mice, rats, hamsters, gerbils, and rabbits) | Piperazine citrate in drinking water at 3 grams/liter | PO | continuous | 2 weeks | 🌎 NA |
| Pinworms (Rabbits) | 100 mg/kg PO q24h | PO | q24h | 2 days | 🌎 NA |
| Pinworms (Rabbits) | Adults: 200-500 mg/kg PO q24h. Young rabbits: 750 mg/kg, PO once daily | PO | q24h | 2 days | 🌎 NA |
| Pinworms/tapeworms (Mice, Rats, Gerbils, Hamsters, Guinea pigs, Chinchillas) | 2-5 mg/mL drinking water | PO | continuous | 7 days, off 7 days and repeat | 🌎 NA |
- Pinworms (Rabbits): Piperazine citrate. Wash the perianal area.
- Pinworms (Rabbits): Piperazine adipate. Wash the perianal area.
- Pinworms/tapeworms (Mice, Rats, Gerbils, Hamsters, Guinea pigs, Chinchillas): Piperazine citrate
Birds
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ascarids in poultry | 100-500 mg/kg PO once | PO | once | Repeat in 10-14 days | 🌎 NA |
| Nematodes in raptors | 100 mg/kg | PO | once | — | 🌎 NA |
| Nematodes in parakeets and canaries | 0.5 mg/gram | PO | once | — | 🌎 NA |
| Ascaridia galli in poultry | 32 mg/kg (as base) (approximately 0.3 grams for each adult) | PO | once | Given in each of 2 successive feedings or for 2 days in drinking water | 🌎 NA |
- Ascarids in poultry: Not effective in psittacines
- Nematodes in raptors: Piperazine citrate
- Nematodes in parakeets and canaries: Piperazine citrate
- Ascaridia galli in poultry: Citrate or adipate salts usually used in feed; hexahydrate in drinking water
Reptiles
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Nematodes | 40-60 mg/kg PO | PO | once | Repeat in two weeks | 🌎 NA |
- Nematodes: Follow with a fecal examination 14 days after the second dose. If positive, give a third dose and continue cycle until cleared.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Treatment of ascarids | 110 mg/kg (base) PO | PO | once | Repeat in 3-4 weeks | 🌎 NA |
| Treatment of ascarids | 200 mg/kg, PO | PO | once | — | 🌎 NA |
- Treatment of ascarids: Retreating at 10-week intervals for P. equorum infections in young animals is recommended
- Treatment of ascarids: Maximum of 80 grams in adults, 60 grams in yearlings, and 30 grams in foals
Swine
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ascaris suum and Oesophagostomum | 0.2-0.4% in the feed, or 0.1-0.2% in the drinking water | PO | once | Consume within 12 hours | 🌎 NA |
| Ascaris suum and Oesophagostomum | 110 mg/kg (as base) | PO | once | Consume in 8-12 hours | 🌎 NA |
- Ascaris suum and Oesophagostomum: Fasting or withholding water overnight may be beneficial. Retreat in 2 months. Safe in young animals and pregnancy.
- Ascaris suum and Oesophagostomum: Citrate salt usually used in feed as a one-day treatment, and hexahydrate in drinking water.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Piperazine is a narrow-spectrum anthelmintic used primarily for the treatment of ascarids (roundworms) in dogs, cats, horses, swine, and poultry.
- It is considered safe to use in animals with concurrent gastroenteritis and during pregnancy.
- Clinical Pearl: Because piperazine is only effective against adult ascarids and lacks efficacy against hookworms, whipworms, or tapeworms, its use in modern veterinary medicine has largely been replaced by broader-spectrum anthelmintics such as pyrantel, fenbendazole, and macrocyclic lactones.
- Available in various salt forms (citrate, adipate, phosphate, hexahydrate, dihydrochloride), which contain varying amounts of the active piperazine base.
Mechanism of action
Piperazine exerts a 'curare-like' effect on susceptible nematodes.
- It acts as a GABA receptor agonist and blocks acetylcholine at the myoneural junction of the parasite.
- This causes flaccid paralysis (narcotizing the worm), allowing the live, paralyzed worms to be passed out of the host's gastrointestinal tract with the feces.
- In ascarids, it also inhibits succinic acid production.
Safety & warnings
Contraindications
- Chronic liver disease
- Chronic kidney disease
- Gastrointestinal hypomotility
- Chronic renal failure
- Hepatic impairment
- Heavy worm burdens (relative contraindication due to risk of intestinal impaction)
Adverse effects
- Diarrhea
- Emesis
- Transient softening of feces (horses)
- Neurological signs at high doses (ataxia, tremors)
Precautions
Important: Use with caution in patients with seizure disorders.
Equine Warning: In horses with heavy infestations of Parascaris equorum, rupture or blockage of the intestines is possible due to the rapid death and detachment of a large worm burden.
- Laboratory Interference: Piperazine can affect uric acid blood levels (both falsely high and low values have been reported); interpret results cautiously.
Drug interactions
May precipitate seizures if used concomitantly (data conflicts, but caution is advised)
Not recommended; may eliminate piperazine from the GI tract before its full efficacy is established
Antagonistic modes of action (pyrantel causes spastic paralysis, piperazine causes flaccid paralysis); should not be used together
Antagonistic mechanism of action (Pyrantel causes spastic paralysis, Piperazine causes flaccid paralysis)
Antagonistic mechanism of action
Monitoring
- Clinical and/or laboratory efficacy (fecal examinations)
- Adverse effects (neurological signs, GI upset)
- Fecal flotation (to confirm clearance of roundworms)
- Adverse neurological signs
Pharmacokinetics
Absorption
Readily absorbed from the proximal sections of the gastrointestinal tract.
Distribution
Specific distribution kinetics on individual species were not located.
Metabolism
Metabolized by the kidneys.
Elimination
Excreted by the kidneys.
Overdose
Piperazine generally has a wide margin of safety (oral LD50 of piperazine adipate in mice is 11.4 g/kg). However, acute massive overdosage can lead to paralysis and death.
Feline Toxicity: In cats, adverse effects occur within 24 hours after a toxic dose is ingested. Clinical signs include:
- Emesis, hypersalivation, dehydration
- Weakness, dyspnea, depression
- Muscular fasciculations of ears, whiskers, tail, and eyes
- Rear limb ataxia, head-pressing
- Positional nystagmus and slowed pupillary responses (Many of these effects may also be seen in dogs after toxic ingestions.)
Treatment:
- Symptomatic and supportive care.
- If ingestion was recent, use of activated charcoal and a cathartic is suggested.
- Intravenous fluid therapy.
- Keep the animal in a quiet, dark place.
- Recovery generally takes place within 3-4 days.
Available products
Formulations
- Oral liquid/suspension
- Oral paste
- Powder/granules for feed or drinking water
- Oral: 500 mg tablets
- Various oral liquids and powders
Veterinary
- Piperazine Dihydrochloride tablets equivalent to 50 mg or 250 mg base (Pipa-Tabs®)
- Alfalfa Pellet Horse Wormer
- Tasty Paste® Dog & Puppy Wormer
- Wonder Wormer™ for Horses
- D-Worm™ Liquid Wormer for Cats and Dogs
- Wazine®-17
- Wazine®-34
- Hartz® Advanced Care™ Liquid Wormer
- Sergeant's® Vetscription® Worm-Away®
- WormEze™ Canine & Feline Anthelmintic
- Various authorized proprietary products (AVM-GSL)
- 500 mg tablets
Regulatory status
Authorised Veterinary Medicine - General Sales List
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Unless otherwise specified by the manufacturer, piperazine products should be stored at room temperature (15-30°C).
Client information
- Administer exactly as directed: Give only the amount prescribed by your veterinarian. Do not overdose.
- Retreatment is usually necessary: Because the medication only kills adult worms in the intestines and does not affect migrating larvae in the tissues, a second dose is typically required 2 to 3 weeks after the first dose.
- Monitor for side effects: Contact your veterinarian immediately if you notice any serious adverse effects such as vomiting, diarrhea, severe weakness, muscle twitching, or uncoordinated walking (ataxia).
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.