Iron Dextran — Veterinary Vademecum Drug Reference

Dosage & Administration Guidelines

Species	Route	Dose	Frequency	Duration & Clinical Notes
Piglet	IM	100-200 mg per piglet (usually 1-2 mL of 100 mg/mL solution)	Single dose at 2-4 days of age; may repeat at 2-3 weeks if needed	Duration: Single dose or as needed Notes: Administer deep IM in the neck or ham. Avoid injection into the hind leg to prevent lameness.
Dog	IM	10-20 mg/kg (as elemental iron)	Every 2-3 days until anemia resolves	Duration: Variable, based on response Notes: Use with caution; oral iron is preferred in dogs unless severe deficiency or malabsorption.
Cat	IM	10-20 mg/kg (as elemental iron)	Every 2-3 days until anemia resolves	Duration: Variable, based on response Notes: Use with caution; oral iron is preferred in cats unless severe deficiency or malabsorption.
Calf	IM	200-400 mg per calf	Single dose at birth or as needed	Duration: Single dose Notes: For prevention of iron deficiency in calves raised on milk replacer.
Lamb/Kid	IM	100-200 mg per animal	Single dose at 1-3 days of age	Duration: Single dose Notes: For prevention of iron deficiency in lambs/kids raised indoors.
Horse	IM	10-20 mg/kg (as elemental iron)	Every 2-3 days until anemia resolves	Duration: Variable, based on response Notes: Rarely used; oral iron is preferred. Monitor for adverse reactions.

Clinical Indications & Species Uses

General Indications

Prevention and treatment of iron deficiency anemia in neonatal piglets
Iron supplementation in animals with chronic blood loss or malabsorption

Dog (Canine)

Treatment of iron deficiency anemia
Supportive therapy in chronic blood loss or hookworm infestation

Cat (Feline)

Treatment of iron deficiency anemia
Supportive therapy in chronic renal disease with anemia

Horse (Equine)

Treatment of iron deficiency anemia (rarely used)
Supportive therapy in chronic blood loss

Cattle (Bovine)

Prevention and treatment of iron deficiency anemia in calves
Supportive therapy in parasitic infections

Small Ruminants (Sheep / Goat)

Prevention and treatment of iron deficiency anemia in lambs and kids

Rabbit & Small Mammals

Treatment of iron deficiency anemia (rarely used)

Avian & Poultry

Treatment of iron deficiency anemia (rarely used)

Exotic & Other Species

Treatment of iron deficiency anemia in some exotic species (e.g., ferrets, reptiles)

Pharmacology & Mechanism of Action

Drug Class: Mineral Supplement / Hematinic | Pharmacological Group: Iron Replacement Agent

Mechanism of Action: Iron dextran is a colloidal solution of ferric hydroxide complexed with dextran. After parenteral administration, the complex is taken up by the reticuloendothelial system, where the dextran is metabolized and the iron is slowly released. The released iron binds to transferrin and is transported to the bone marrow for incorporation into hemoglobin, myoglobin, and iron-containing enzymes. It replenishes iron stores and corrects iron deficiency anemia.

Pharmacodynamics: Iron dextran provides a stable, slowly released source of iron for erythropoiesis. It increases serum iron levels and ferritin stores, and stimulates hemoglobin synthesis. The onset of action is gradual, with peak reticulocyte response typically seen within 5-7 days. It is effective in treating and preventing iron deficiency anemia, particularly in neonatal piglets.

⚡ Pharmacokinetics Summary

Absorption: Iron dextran is not absorbed orally; it is administered parenterally (IM or SC). After injection, the complex is absorbed from the injection site into the lymphatic system and then into the bloodstream. Absorption is slow and sustained, with a depot effect at the injection site.

Distribution: Iron dextran is distributed throughout the body, primarily to the reticuloendothelial system (liver, spleen, bone marrow). It crosses the placenta minimally and is excreted in milk in small amounts.

Metabolism: The iron-dextran complex is phagocytosed by macrophages, and the dextran is hydrolyzed by lysosomal enzymes. Iron is released and stored as ferritin or hemosiderin, or transported by transferrin.

Excretion: Iron is not actively excreted; small amounts are lost via bile, urine, sweat, and desquamation of epithelial cells. The dextran moiety is metabolized to glucose and carbon dioxide.

Half-Life: The half-life of iron dextran is approximately 5-20 hours for the iron component, but the release from the complex is prolonged over days to weeks.

Bioavailability: Parenteral administration provides 100% bioavailability. Oral absorption is negligible.

Protein Binding: Iron is bound to transferrin in the plasma; the iron-dextran complex itself is not protein-bound but is taken up by cells.

Available Formulations & Strengths

Injectable Solution 100 mg/mL (as elemental iron) (IM)

Injectable Solution 200 mg/mL (as elemental iron) (IM)

Contraindications & Clinical Warnings

Contraindications:

Known hypersensitivity to iron dextran
Anemia not due to iron deficiency (e.g., hemolytic anemia, aplastic anemia)
Iron overload conditions (hemochromatosis, hemosiderosis)
Severe hepatic or renal impairment (use with caution)
Concurrent infections (may exacerbate bacterial growth)

Warnings & Clinical Precautions:

Administer deep IM to avoid tissue staining and irritation.
Use with caution in animals with a history of allergic reactions.
Do not administer intravenously (risk of anaphylaxis).
Monitor for signs of iron toxicity (vomiting, diarrhea, lethargy).
In piglets, avoid injection into the ham to prevent lameness.
Use in pregnant animals only if clearly needed (safety not established).
May cause staining of tissues at injection site.

Adverse Effects & Reactions

Common:

Pain at injection site
Tissue staining
Local swelling
Transient lethargy

Serious / Severe:

Anaphylactic reaction
Iron toxicity (hemosiderosis)
Hepatotoxicity
Cardiovascular collapse (rare)

Rare:

Sarcoma at injection site (reported in cats)
Neurotoxicity
Gastrointestinal ulceration

Key Drug Interactions

Interacting Drug / Class	Clinical Effect & Mechanism	Severity
Oral iron supplements	Additive iron levels; risk of iron toxicity	High
Chloramphenicol	May reduce erythropoietic response to iron	Moderate
Vitamin E	May reduce oxidative stress and improve iron utilization	Mild
Antacids or proton pump inhibitors	May reduce oral iron absorption (if oral iron is used concurrently)	Mild

Overdose & Toxicity Management

Signs of Toxicity:

Vomiting
Diarrhea (often bloody)
Lethargy
Metabolic acidosis
Hepatic necrosis
Cardiovascular collapse
Coma

Emergency Treatment Protocol: There is no specific antidote. Treatment is symptomatic and supportive: induce emesis if recent oral ingestion (but iron dextran is parenteral). For parenteral overdose, provide supportive care including IV fluids, oxygen, and monitoring of vital signs. Administer chelating agents such as deferoxamine (10-15 mg/kg IV or IM) in severe cases. Treat acidosis with sodium bicarbonate. Provide gastrointestinal protectants if GI signs occur.

Food Animal Withdrawal Times

🥩 Meat: 21 days🥛 Milk: 0 days

Withdrawal times may vary by country and formulation. Consult local regulations. For cattle and swine, a meat withdrawal time of at least 21 days is commonly recommended. No milk withdrawal is typically required for lactating animals, but verify with label.

Storage, Handling & Regulatory Information

Storage Temperature: Store at controlled room temperature (15-30°C). Protect from freezing.

Light Sensitivity: Light-sensitive — protect from direct exposure.

Handling & Special Conditions: Protect from light. Keep container tightly closed. Do not use if precipitate forms.

Dispensing Status: Over-The-Counter (OTC)

Approval Status: Approved for use in swine and cattle in the US. Other species may be extra-label.

Extra-Label (Off-Label) Use: In the US, iron dextran is available as an OTC product for veterinary use. Extra-label use in food animals requires a valid veterinary-client-patient relationship and must comply with AMDUCA regulations. Withdrawal times must be observed.

Clinical Pearls & Practice Notes

💡 Clinical Insights: Iron dextran is primarily used in neonatal piglets to prevent iron deficiency anemia, as sow's milk is low in iron. It is also used in calves, lambs, and kids raised on milk replacer. In companion animals, oral iron is preferred unless there is malabsorption or severe deficiency. Administer deep IM to minimize tissue irritation. Monitor for signs of anaphylaxis, especially in horses and cats. Iron dextran should not be used in animals with anemia not caused by iron deficiency. Always calculate the dose based on elemental iron content. In food animals, adhere to withdrawal times.

References & Literature

📚 Plumb's Veterinary Drug Handbook
📚 Papich Veterinary Pharmacology and Therapeutics
📚 Compendium of Veterinary Products (CVP)