Table of Contents 17 sections Group Mechanism of Action Dose Rates Dog Cat Horse Cattle Ferret Rabbit Reptile Bird Indications Contraindications Interactions Adverse effects Preparations Monitoring and Administration
Furosemide (Frusemide) Furosemide, also spelled frusemide, is a potent loop diuretic widely used to relieve fluid accumulation in veterinary patients. Its principal small-animal application is pulmonary edema and other congestion associated with heart failure. Additional uses include selected electrolyte disorders, edema in large animals and reduction of exercise-induced pulmonary hemorrhage in horses.
Loop diuretic
Furosemide inhibits the sodium–potassium–chloride cotransporter NKCC2 in the thick ascending limb of the loop of Henle. This reduces sodium chloride reabsorption and the medullary concentrating gradient, increasing urinary salt and water loss. Reduced circulating volume and venous pressures help relieve congestion. Increased urinary calcium and potassium excretion contributes to selected electrolyte-management uses.
Dog Use / stage Dose Route Schedule Instructions Edema 2–6 mg/kg IV, IM, SC, PO Every 8–12 h Heart failure — Initial 2 mg/kg PO Every 12 h Heart failure — Maintenance 1–2 mg/kg PO Every 12 h Acute pulmonary edema 2 mg/kg IV Every 0.5 h Intensive monitored treatment; repeat until clinical improvement, reassessing hydration and perfusion. Diuretic infusion — Loading 0.66 mg/kg IV Diuretic infusion — Maintenance 0.66 mg/kg/hour IV Continuous Infuse for 8 hours. Alternative diuretic infusion 0.25 mg/kg/hour IV Continuous Equivalent to a total 2 mg/kg infused over 8 hours in 5% glucose.
Cat Use / stage Dose Route Schedule Instructions Edema 1–4 mg/kg IV, IM, SC, PO Every 8–24 h Start at 1 mg/kg and titrate to response.
Horse Use / stage Dose Route Schedule Instructions Edema 1 mg/kg IM, IV Every 8 h Edema 250–500 mg/animal IM, IV Every 6–8 h Diuretic infusion — Loading 0.12 mg/kg IV Diuretic infusion — Maintenance 0.12 mg/kg/hour IV Continuous EIPH prevention 0.5 mg/kg IV Once Reported timing is 4 hours before exercise or 24 hours before racing; competition rules require separate verification. EIPH prevention 1 mg/kg IV Once Reported timing is 4 hours before exercise or 24 hours before racing; competition rules require separate verification. Heart failure — Maintenance 0.5–2 mg/kg PO, IM Every 8–12 h
Cattle Use / stage Dose Route Schedule Instructions Edema 500 mg/animal IM, IV Every 24 h Edema 250 mg/animal IM, IV Every 12 h
Ferret Use / stage Dose Route Schedule Instructions Acute heart failure — Initial 2–3 mg/kg IV, IM Heart failure — Maintenance 1–2 mg/kg PO Every 12 h Heart failure 1–4 mg/kg PO, SC, IM, IV Every 8–12 h
Rabbit Use / stage Dose Route Schedule Instructions Heart failure 2–5 mg/kg PO, SC, IM, IV Every 12 h Pulmonary edema 1–4 mg/kg IV, IM Every 4–6 h
Reptile Use / stage Dose Route Schedule Instructions Diuresis 5 mg/kg IV, IM As needed
Bird Use / stage Dose Route Schedule Instructions Diuresis 0.1666666667 mg/kg IM Every 12 h Equivalent to 0.05 mg per 300 g; lories are particularly sensitive to overdose.
Treatment of cardiogenic pulmonary edema and other congestive manifestations of heart failure in dogs and cats. Management of selected noncardiac edema or effusions when removal of retained fluid is clinically appropriate. Adjunctive promotion of calcium excretion in selected hypercalcemic patients after restoration of hydration. Adjunctive enhancement of potassium excretion in selected hyperkalemic patients with adequate renal urine production. Reduction of exercise-induced pulmonary hemorrhage in horses within an appropriate equine treatment program. Treatment of selected edema syndromes in cattle, including udder edema. Use cautiously with volume depletion, electrolyte depletion or concurrent ACE inhibition. Aminoglycosides and amphotericin increase renal/ototoxic risk. NSAIDs may reduce response. Acidic mixtures can cause precipitation. Dehydration, azotemia and electrolyte losses RAAS activation and reduced response with repeated dosing SC injection discomfort Preparation Form Strength Route Furosemide (Frusemide) 12.5 mg Tablet 12.5 mg / tablet PO Furosemide (Frusemide) 20 mg Tablet 20 mg / tablet PO Furosemide (Frusemide) 40 mg Tablet 40 mg / tablet PO Furosemide (Frusemide) 50 mg Tablet 50 mg / tablet PO Furosemide (Frusemide) 80 mg Tablet 80 mg / tablet PO Furosemide oral solution 10 mg/mL Oral Liquid 10 mg / mL PO Furosemide injection 50 mg/mL Injection 50 mg / mL IV, IM, SC
Monitor hydration, urine output, electrolytes and renal parameters. Increased urine production does not establish improved AKI outcome.
Equine oral absorption is poor. Avoid acidic admixtures and discard discolored solutions.
