Edetate Calcium Disodium (EDTA)

Edetate calcium disodium, or calcium disodium EDTA, is a metal-chelating agent used primarily for lead poisoning. Veterinary applications include intoxications in dogs, cats, birds and selected other species. It is a calcium-containing EDTA salt with a pharmacologic role distinct from that of edetate disodium, which has different effects on circulating calcium.

Group

Chelating antidote

Mechanism of Action

Calcium disodium EDTA exchanges its calcium for accessible metals with greater binding affinity, particularly lead, forming water-soluble chelate complexes. These complexes are eliminated mainly through the kidneys, reducing the accessible body burden of lead. Chelation can promote redistribution from tissue pools into an eliminable form, although removal depends on metal accessibility and renal excretion.

Dose Rates

Dog

Use / stage	Dose	Route	Schedule	Instructions
Lead intoxication	25 mg/kg	SC, IM, IV	Every 6 h	Up to 5 days; Source course 2–5 days. Correct dilution and renal monitoring are required; never substitute disodium EDTA.

Cat

Use / stage	Dose	Route	Schedule	Instructions
Lead intoxication	25 mg/kg	SC, IM, IV	Every 6 h	Up to 5 days; Source course 2–5 days. Correct dilution and renal monitoring are required; never substitute disodium EDTA.

Chinchilla

Use / stage	Dose	Route	Schedule	Instructions
Lead poisoning	30 mg/kg	SC	Every 12 h

Horse

Use / stage	Dose	Route	Schedule	Instructions
Lead poisoning course	Reference only	IV		75 mg/kg/day slowly in saline or D5W for 4–5 days, either once daily or in 2–3 divided administrations. Rest two days before a further 4–5-day course; remove all accessible lead and maintain hydration.

Cattle

Use / stage	Dose	Route	Schedule	Instructions
Lead poisoning staged course	Reference only	IV		Alternative A: 67 mg/kg slowly twice daily for two days, withhold two days, then repeat for two days. Alternative B: 73.3 mg/kg/day divided into 2–3 slow IV doses for 3–5 days; rest two days before another five-day course.

Bird

Use / stage	Dose	Route	Schedule	Instructions
Lead poisoning	35 mg/kg	IM	Every 12 h	Up to 7 days; Psittacines; described initial course 5–7 days. Maintain hydration and monitor renal function.
Lead poisoning	100 mg/kg	IM	Every 12 h	Up to 25 days; Falcon study using undiluted 25% calcium disodium EDTA: five-day courses repeated according to blood lead, up to 25 consecutive days. Not a general avian regimen.
Lead or zinc poisoning	30–35 mg/kg	IM	Every 12 h	Up to 5 days; Course 3–5 days, followed by a 3–5-day rest before reassessment or repeat therapy. Maintain hydration; oral EDTA can increase intestinal lead uptake.
Lead or zinc poisoning	20–35 mg/kg	IV		Up to 2 days; Diluted in saline; the source does not specify a repeat interval.

Indications

Chelation treatment of acute or chronic lead intoxication in dogs, cats, birds and other veterinary patients.
Treatment of selected zinc intoxications, particularly in birds, within an appropriate metal-specific toxicology plan.

Contraindications

Never substitute edetate disodium: potentially fatal hypocalcemia can result.
Establish adequate urine flow before dosing.

Interactions

May chelate medicines or metals mixed with it; combination treatment with dimercaprol requires a defined plan.

Adverse effects

Pain with IM administration
Possible hypersensitivity and renal injury

Preparations

Preparation	Form	Strength	Route
Edetate calcium disodium injection 200 mg/mL	Injection	200 mg / mL	SC, IM, IV

Monitoring and Administration

Monitor renal function, urine output and lead concentrations.

The source small-animal section provides 25 mg/kg every 6 hours for 2–5 days; large-animal species are not separately named. Ensure appropriate dilution and adequate urine flow.