Calcium EDTA (Calcium Disodium Edetate): veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

CaNa2EDTA, Calcium disodium versenate, Calcium edetate

Species with doses

Dogs, Cats, Cattle, Horses, Birds and Small mammals

General dose range

25–27 mg/kg SC q6h (or divided q12h) for ~5 days — check the species tables for the indication

Routes

SC, IM, IV

Last reviewed

1 October 2026

Indications

• Lead poisoning (plumbism) — chelation to reduce blood/tissue lead
• Zinc toxicosis (adjunct chelation in some protocols)
• Severe/CNS lead poisoning — with dimercaprol (BAL)

Calcium EDTA (Calcium Disodium Edetate) 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

• Lead poisoning: Papich 5e: 25 mg/kg q6h for 2–5 days SC, IM or IV. Plumb’s p.453: 100 mg/kg/day SC divided four times daily in 5% dextrose (1% solution) for 5 days; do not exceed 2 g/day or 5 consecutive days; rest 5–7 days between courses (nephrotoxicity). Remove GI lead first. Zinc toxicity: same 100 mg/kg/day divided q6h SC. Succimer is now preferred for lead in small animals.

Cats

• Lead poisoning: Plumb’s p.453 (Reid & Oehme): 27.5 mg/kg in 15 mL D5W SC four times daily for 5 days; recheck blood lead 2–3 weeks later and repeat if >0.2 ppm. Papich 5e: 25 mg/kg q6h for 2–5 days. Maintain hydration; monitor renal function.

Cattle

• Lead poisoning: Plumb’s p.453: 110 mg/kg/day in 3–4 divided doses, first IV then SC (Post & Keller); 67 mg/kg slow IV twice daily for 2 days, off 2 days, repeat (Bailey); 73.3 mg/kg/day divided 2–3 times for 3–5 days (Sexton & Buck). Papich 5e: 25 mg/kg q6h for 2–5 days. FARAD: 2-day meat and milk withdrawal. Recovery may take 10–14 days.

Horses

• Lead poisoning: Plumb’s p.453 (Oehme 1987): 75 mg/kg/day slowly IV in D5W or saline. Papich 5e: 25 mg/kg q6h for 2–5 days. Remove the lead source; supportive nutrition.

Buffalo

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

• Lead poisoning: Plumb’s p.453: 110 mg/kg/day in 3–4 divided doses, first IV then SC (Post & Keller); 67 mg/kg slow IV twice daily for 2 days, off 2 days, repeat (Bailey); 73.3 mg/kg/day divided 2–3 times for 3–5 days (Sexton & Buck). Papich 5e: 25 mg/kg q6h for 2–5 days. FARAD: 2-day meat and milk withdrawal. Recovery may take 10–14 days.

Birds

• Lead poisoning (waterfowl/raptors/psittacines): Plumb’s p.453: psittacines 35 mg/kg IM q12h for 5–7 days (McDonald); lead or zinc 30–35 mg/kg IM q12h for 3–5 days, off 3–5 days, repeat (Johnson-Delaney & Reavill) — IV 20–35 mg/kg diluted for up to 48 h; falcons 100 mg/kg IM q12h was tolerated in one study. Never give orally (increases lead absorption). Maintain hydration.

Small mammals

• Lead poisoning (chinchillas): Plumb’s p.453 (Adamcak & Otten 2000): chinchillas 30 mg/kg SC q12h.

Contraindications

Anuria / significant renal failure (lead-EDTA chelate is renally excreted and the drug is nephrotoxic). Use of the SODIUM (not calcium) EDTA salt — causes lethal hypocalcaemia. Concentrated/undiluted bolus administration. Active GI lead (remove gut lead first — chelation can increase absorption). Known hypersensitivity.

Species-specific warnings

Birds: Lead poisoning is common in waterfowl/raptors/psittacines (shot/paint/solder) — chelate with EDTA, hydrate, and remove particulate lead from the gut (it keeps re-poisoning the bird).

Adverse effects

• Nephrotoxicity (renal tubular damage) — dose/duration-related
• GI upset (vomiting, diarrhoea)
• Depression/lethargy; injection-site reaction (if not diluted)
• Zinc depletion with prolonged use

Drug interactions

• Dimercaprol (BAL): complementary for severe/CNS lead poisoning
• Zinc/other essential metals: depleted with prolonged chelation
• Other nephrotoxins: additive renal injury
• Oral lead in the gut: chelation can enhance lead absorption — decontaminate the GI tract first

Pregnancy and lactation

Use for serious lead poisoning when maternal benefit outweighs risk; can deplete essential metals — monitor.

Monitoring

• Renal function (BUN/creatinine, urinalysis) before and during therapy — nephrotoxic
• Blood lead level (response; repeat courses if still elevated)
• Hydration/urine output; electrolytes (zinc depletion)
• Decontaminate GI tract of particulate lead before chelation

Toxicity and overdose

The dose-limiting toxicity is NEPHROTOXICITY (renal tubular necrosis), worsened by dehydration and prolonged/high-dose use — hence dilution, hydration, ~5-day courses and rest periods. It also depletes zinc. The catastrophic error is using sodium EDTA instead of the CALCIUM salt, which chelates the patient's own calcium causing fatal hypocalcaemic tetany.

Management: No specific antidote. Discontinue; aggressive IV fluid support to protect/flush the kidneys, monitor renal function and electrolytes (including calcium/zinc). For inadvertent sodium-EDTA hypocalcaemia, give IV calcium. Supportive care; resume chelation only after renal recovery.

Clinical pearls

• The workhorse LEAD chelator — dilute it, give SC (divided) or slow IV, keep the patient well hydrated, and run ~5-day courses with rest periods (it is nephrotoxic)
• Remove GI lead FIRST (chelation can increase lead absorption from the gut) and add dimercaprol (BAL) for CNS signs/very high burdens
• Use the CALCIUM disodium salt only — plain sodium EDTA causes fatal hypocalcaemia
• Monitor renal values and blood lead; a common, treatable poisoning in dogs, waterfowl and birds (lead shot/paint)

Mechanism of action

Calcium disodium EDTA is a chelating agent that readily exchanges its loosely bound calcium for divalent/trivalent heavy-metal ions — especially lead — forming a stable, non-toxic, water-soluble metal-EDTA complex that is filtered and excreted by the kidneys. This removes lead from blood and (more slowly) soft tissue/bone, reducing toxicity. Because it does not penetrate cells well, very high or CNS burdens are co-treated with the lipophilic chelator dimercaprol.

Formulations and products

• Injection 200 mg/mL (dilute before use)
• Calcium Disodium Versenate — 200 mg/mL injection (dilute), Injection (human-label)

Storage

Injection: 15–30 °C, protect from light; DILUTE before administration (hypertonic/irritant). Use the calcium disodium salt only.

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.

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Frequently asked questions