Home/Medicines/Furosemide

Furosemide

PrescriptionCDSCO approved

Loop diuretic

Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

4 available

Interactions

26 documented

Formulations

Mechanism of action

Inhibits the Na+/K+/2Cl- co-transporter in the thick ascending limb of the loop of Henle, causing potent diuresis and natriuresis

At a glance

Class

Loop diuretic

Schedule

Prescription

Storage

Store below 25°C, protect from light. Injectable solution may discolour — discard if yellow.

CDSCO (India)

Vet-approved — 1970-01

Dosing

🐕

Dog

Congestive heart failure (acute pulmonary oedema)

Dose

2–8 mg/kg

Route

IV, IM

Frequency

Every 1-4 hours until stable

Max dose

200 mg/dose; 600 mg/day

Duration: Until respiratory rate <40/min, then taper to oral maintenance

CHF maintenance

Dose

1–6 mg/kg

Route

Frequency

BID-TID

Max dose

200 mg/dose; 600 mg/day

Duration: Lifelong — use lowest effective dose

CRI for refractory CHF

Dose

0.66–1 mg/kg/hr

Route

IV CRI

Frequency

Continuous infusion

Max dose

1 mg/kg/hr/dose; 24 mg/kg/hr/day

Duration: Until stabilised

🐈

Cat

Congestive heart failure

Dose

1–4 mg/kg

Route

IV, IM, PO

Frequency

BID-TID (acute: every 1-4h)

Max dose

40 mg/dose; 120 mg/day

Duration: Lifelong maintenance; acute dosing as needed

Educational reference only

This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Formulations

💊

Tablet — 2

Strength

20mg

Available in India

Strength

40mg

Available in India

💉

Injectable — 1

Strength

10mg/mL

Available in India

🧴

Oral solution — 1

Strength

10mg/mL

Available in India

Storage

Store below 25°C, protect from light. Injectable solution may discolour — discard if yellow.

Safety

Absolute contraindications — do not use

Anuria / severe renal failure (oliguric)
Ineffective in anuria; may worsen electrolyte depletion
Severe dehydration/hypovolaemia
Diuresis worsens hypovolaemia

Use with caution

Concurrent aminoglycosides
Synergistic ototoxicity and nephrotoxicity
Hypokalaemia
Furosemide causes K+ wasting — supplement or use with spironolactone

Adverse effects

Common

Polyuria/polydipsia

Electrolyte depletion (K+, Na+, Cl-)

Dehydration

Serious

Ototoxicity (rapid IV administration)

Acute renal failure (dehydrated patients)

Severe hypokalaemia

Monitoring parameters

Respiratory rate (resting)Renal function (BUN, Creatinine)Electrolytes (K+, Na+, Cl-)Hydration statusBody weight

Educational reference only

Interactions

Major — 10

Gentamicin

major

Both are ototoxic and nephrotoxic; furosemide enhances aminoglycoside ototoxicity

Management: Avoid concurrent use if possible. If unavoidable, monitor renal function (BUN/creatinine) and hearing closely.

Digoxin

major

Furosemide-induced hypokalemia increases risk of digoxin toxicity (arrhythmias)

Management: Monitor serum potassium and digoxin levels closely. Supplement potassium if needed.

Potassium Bromide

major

Loop diuretics increase renal bromide excretion by competing for chloride reabsorption, causing rapid drop in bromide levels

Management: Avoid furosemide in patients on potassium bromide. If diuretic needed, use a non-loop diuretic. Monitor bromide levels.

Cyclophosphamide

major

Furosemide inhibits renal excretion of cyclophosphamide metabolites, increasing risk of hemorrhagic cystitis

Management: Avoid concurrent use. Ensure adequate hydration and frequent voiding during cyclophosphamide therapy.

Amphotericin B

major

Furosemide potentiates amphotericin B nephrotoxicity through renal vasoconstriction and electrolyte depletion

Management: Avoid concurrent use. Ensure aggressive fluid therapy during amphotericin B administration.

Gentamicin (Systemic)

major

Furosemide increases aminoglycoside nephrotoxicity by concentrating gentamicin in renal tubular cells and reducing renal blood flow.

Management: Avoid concurrent use when possible. If unavoidable, ensure adequate hydration, monitor BUN/creatinine q24-48h, and use once-daily aminoglycoside dosing.

Amikacin

major

Furosemide increases aminoglycoside nephro- and ototoxicity by concentrating drug in renal tubules and inner ear.

Management: Avoid concurrent use. If unavoidable, maintain hydration, monitor renal function, and monitor for vestibular signs.

Cisplatin

major

Furosemide increases cisplatin nephrotoxicity by concentrating cisplatin in renal tubules and reducing renal blood flow. Contrast: saline diuresis is protective.

Management: Do NOT use furosemide with cisplatin. Use aggressive saline diuresis (NaCl 0.9%) before, during, and after cisplatin infusion instead.

Neomycin

major

Furosemide increases aminoglycoside nephro- and ototoxicity by concentrating drug in renal tubules and inner ear.

Management: Avoid concurrent systemic use. Oral neomycin (for hepatic encephalopathy) has minimal systemic absorption and lower risk.

Tobramycin

major

Furosemide concentrates aminoglycoside in renal tubules and inner ear, increasing nephro- and ototoxicity risk.

Management: Avoid if possible. If both needed, ensure aggressive hydration and monitor BUN/creatinine q24-48h.

Moderate — 15

Prednisolone

moderate

Both cause potassium loss; combined use increases risk of hypokalaemia

Management: Monitor serum potassium. Consider potassium supplementation if concurrent use is prolonged.

Enalapril

moderate

ACE inhibitors + loop diuretics can cause excessive hypotension and prerenal azotaemia

Management: Standard cardiac combination but start ACE inhibitor at low dose. Monitor renal values and blood pressure.

Benazepril

moderate

ACE inhibitors + loop diuretics can cause excessive hypotension and prerenal azotaemia

Management: Standard cardiac combination. Start ACE inhibitor at low dose. Monitor renal values and blood pressure.

Mannitol

moderate

Additive diuretic effect; both cause significant fluid and electrolyte loss

Management: Used together in cerebral oedema management. Monitor hydration, electrolytes, and urine output closely.

Meloxicam

moderate

NSAIDs reduce prostaglandin-mediated renal blood flow and sodium excretion, decreasing diuretic efficacy and increasing nephrotoxicity risk.

Management: Monitor urine output and renal function. May need to increase furosemide dose. Avoid in dehydrated or azotemic patients.

Carprofen

moderate

NSAIDs antagonize diuretic effect of furosemide by inhibiting renal prostaglandins. Risk of acute kidney injury.

Management: Monitor renal function and diuretic response. Avoid in hemodynamically unstable patients.

Deracoxib

moderate

NSAID reduces prostaglandin-mediated renal blood flow and sodium excretion, decreasing diuretic efficacy.

Management: Monitor urine output and renal function. May need to increase furosemide dose.

Lisinopril

moderate

First-dose hypotension risk when adding ACE inhibitor to loop diuretic (volume-depleted, activated RAAS).

Management: Start ACE inhibitor at low dose. Monitor blood pressure.

Metformin

moderate

Furosemide may reduce metformin renal clearance, increasing metformin levels and lactic acidosis risk. Furosemide-induced dehydration further increases risk.

Management: Monitor renal function and hydration. Lactic acidosis risk increases with dehydration or renal impairment.

Calcitriol

moderate

Furosemide increases renal calcium excretion, opposing calcitriol's calcium-retaining effect.

Management: May need higher calcitriol dose or calcium supplementation. Monitor ionized calcium.

Hydralazine

moderate

Additive blood pressure reduction. Both reduce preload/afterload via different mechanisms.

Management: Standard heart failure combination. Monitor blood pressure. Start hydralazine at low dose.

Ketorolac

moderate

Ketorolac reduces renal prostaglandin-mediated blood flow and sodium excretion, decreasing furosemide diuretic efficacy.

Management: Monitor urine output and renal function.

Desmopressin

moderate

Furosemide directly opposes desmopressin's antidiuretic effect by promoting renal water excretion.

Management: Usually counterproductive to combine. If both genuinely needed, monitor urine output and serum sodium.

Albuterol (Salbutamol)

moderate

Both cause hypokalemia via different mechanisms (albuterol: intracellular K+ shift; furosemide: renal K+ loss). Combined: significant hypokalemia risk.

Management: Monitor serum potassium. Supplement if K+ <3.5 mEq/L. Particularly important in cardiac patients.

Fludrocortisone

moderate

Pharmacologically opposing: fludrocortisone retains sodium/water (mineralocorticoid); furosemide promotes sodium/water excretion. Also both cause potassium loss — additive hypokalemia risk.

Management: Combination is contradictory in most situations. Monitor electrolytes if both genuinely needed. Watch for hypokalemia.

Minor — 1

Pimobendan

minor

Standard CHF triple therapy. Complementary mechanisms. No significant pharmacokinetic interaction.

Management: Cornerstone CHF therapy. Monitor renal function and electrolytes.

Educational reference only

Brands

International

Lasix

Sanofi

India

Fruselac

Intas

Lasix

Sanofi

Furoped

Virbac

FAQs

Frequently asked questions

›What is Furosemide?

Furosemide is a loop diuretic used in pets. Inhibits the Na+/K+/2Cl- co-transporter in the thick ascending limb of the loop of Henle, causing potent diuresis and natriuresis

›What is Furosemide used for in pets?

Furosemide is used in veterinary medicine for: Congestive heart failure (acute pulmonary oedema); CHF maintenance; CRI for refractory CHF; Congestive heart failure.

›What is the Furosemide dose for dogs?

For dogs, Furosemide is typically dosed as follows — Congestive heart failure (acute pulmonary oedema): 2–8 mg/kg IV/IM Every 1-4 hours until stable; CHF maintenance: 1–6 mg/kg PO BID-TID; CRI for refractory CHF: 0.66–1 mg/kg/hr IV CRI Continuous infusion. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Furosemide dose for cats?

For cats, Furosemide is typically dosed as follows — Congestive heart failure: 1–4 mg/kg IV/IM/PO BID-TID (acute: every 1-4h). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What are the side effects of Furosemide?

Common: Polyuria/polydipsia, Electrolyte depletion (K+, Na+, Cl-), Dehydration. Serious (call your vet immediately): Ototoxicity (rapid IV administration), Acute renal failure (dehydrated patients), Severe hypokalaemia.

›Does Furosemide need a prescription?

Yes. Furosemide is a prescription medication and should only be administered under veterinary supervision.

›When should Furosemide not be used?

Do not use Furosemide if: Anuria / severe renal failure (oliguric); Severe dehydration/hypovolaemia.

Educational reference only

References

CDSCO approvals (India) — 1

Injection For (Veterinary Use) Each Ml Contains Buparvaquone …..50mg Furosemide

M/s. Intracin Pharmaceuticals · Approved 27.06.2019

For the treatment of theileriosis (east coast fever) particularly for advanced cases with pulmonary oedema.

Source: CDSCO Veterinary Drug Approval Registry (1969–2026)

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database