Torsemide (Torasemide): veterinary dose and monograph

At a glance

Drug class

Diuretic

Also known as

Torasemide, Dytor, Demadex

Species with doses

Dogs, Cats and Horses

General dose range

0.1–0.3 mg/kg PO q12–24h — check the species tables for the indication

Routes

PO

Last reviewed

1 October 2026

Indications

• Furosemide-refractory or advanced congestive heart failure
• Maintenance diuresis in chronic CHF (convenient once/twice-daily dosing)
• Management of oedema/effusions when a stronger, longer-acting loop diuretic is needed

Torsemide (Torasemide) 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

• Refractory/advanced CHF: Papich 5e: 0.2 mg/kg q12h PO; to switch from furosemide, divide the total daily furosemide dose by 10 and give that twice daily. Plumb’s p.1137: 0.2–0.3 mg/kg q12–24h when other diuretics fail (Rush 2008); 0.2 mg/kg once to three times daily (Atkins 2008). Monitor renal values and electrolytes.

Cats

• Refractory CHF: Plumb’s p.1137 (dogs and cats): 0.2–0.3 mg/kg q12–24h (Rush 2008). Papich 5e: no cat dose reported — the dog dose may be considered. Start at the low end; cats dehydrate and become azotaemic easily.

Horses

• Diuresis / CHF: Papich 5e: horses 0.5–1 mg/kg q12h PO.

Contraindications

Anuria, severe dehydration/hypovolaemia, marked electrolyte depletion (hypokalaemia, hyponatraemia), and significant pre-renal azotaemia. Caution with other nephrotoxins/ototoxins and aggressive concurrent RAAS blockade. Sulfonamide hypersensitivity (related structure). Known hypersensitivity.

Species-specific warnings

Cats: Cats are prone to dehydration and azotaemia — start at the low end and monitor renal values/electrolytes carefully.

Adverse effects

• Dehydration and pre-renal azotaemia (more sustained than furosemide)
• Hypokalaemia, hyponatraemia, hypochloraemic alkalosis
• Hypotension, weakness
• Ototoxicity (high doses, with other ototoxins)
• Activation of RAAS (less than expected due to mild anti-aldosterone effect)

Drug interactions

• ACE inhibitors / other antihypertensives: additive hypotension and azotaemia
• Aminoglycosides / other ototoxins/nephrotoxins: additive toxicity
• Digoxin: diuretic-induced hypokalaemia increases digoxin toxicity
• NSAIDs: blunt diuretic effect and increase nephrotoxicity
• Corticosteroids: additive potassium loss

Pregnancy and lactation

Limited data; diuretic-induced volume contraction can reduce placental perfusion — use only if maternal benefit is clear.

Monitoring

• Renal values (BUN/creatinine) and electrolytes (K, Na, Cl) at baseline and after dose changes
• Hydration status and body weight
• Resting respiratory rate / signs of congestion (efficacy)
• Blood pressure

Toxicity and overdose

Overdose causes profound diuresis with dehydration, electrolyte depletion (hypokalaemia, hyponatraemia), hypotension, collapse and azotaemia; ototoxicity at very high doses. Because it is long-acting and potent, over-diuresis is easier to provoke than with furosemide.

Management: No specific antidote. Stop the drug; rehydrate with IV fluids and correct electrolytes (potassium, sodium, magnesium). Support blood pressure and renal perfusion; monitor renal values and electrolytes until stable. Anticipate a longer recovery than with furosemide owing to its duration.

Clinical pearls

• The escalation drug when furosemide stops controlling CHF — far more potent and longer-acting
• Remember the ~1/10–1/20 conversion from furosemide; over-dosing causes rapid dehydration/azotaemia
• Better, more consistent oral absorption than furosemide — useful when gut oedema limits furosemide uptake
• Monitor electrolytes and renal values closely, especially in cats and CKD patients
• Mild anti-aldosterone action is a bonus in chronic RAAS-activated heart failure

Mechanism of action

Inhibits the Na-K-2Cl co-transporter (NKCC2) in the thick ascending limb of the loop of Henle, blocking sodium, potassium and chloride reabsorption and producing a powerful natriuresis/diuresis. Compared with furosemide it has higher and more predictable oral bioavailability, a longer half-life, and additional mild aldosterone-receptor antagonism, which together give stronger, smoother decongestion.

Formulations and products

• 5 mg tablet
• 10 mg tablet
• 20 mg tablet
• Upcard (Vetoquinol) — Torasemide flavoured tablet (0.75 / 3 / 7.5 / 18 mg), Tablet
• Dytor — 5 / 10 / 20 mg tablet, Tablet (human-label)
• Torsemide — 5 / 10 / 20 mg tablet, Tablet (human-label)

Storage

Tablets: 15–30 °C, dry, protected from light.

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.

Other diuretics

• Furosemide
• Hydrochlorothiazide
• Mannitol
• Spironolactone

Frequently asked questions