Loop diuretic
Lasix (Furosemide)
A powerful diuretic used to remove excess fluid from the body when DCM has progressed to congestive heart failure. Essential for managing fluid in the lungs or abdomen.
Quick facts
Drug class
Loop diuretic
Estimated cost
$5–20/month. One of the most affordable cardiac medications. Widely available as a generic.
Also known as
Lasix, Salix (Furosemide)
How it works
Furosemide works in the kidneys to block sodium and chloride reabsorption, which causes the body to excrete more water as urine. This reduces the fluid overload that occurs in heart failure — clearing fluid from the lungs (pulmonary edema) and abdomen (ascites), making breathing easier.
Common dosage
Highly variable: 1–4 mg/kg two to three times daily, adjusted based on symptoms. In emergencies, may be given by injection. Your vet will find the lowest effective dose to minimize side effects. Dose often needs to increase over time as the disease progresses.
Dosages vary — your vet will determine the right dose for your dog.
Side effects to watch for
- ●Increased thirst and urination (expected — always provide access to fresh water)
- ●Dehydration if over-dosed
- ●Electrolyte imbalances (especially low potassium)
- ●Kidney stress at higher doses
- ●Loss of appetite
- ●Weakness or lethargy
Drug interactions
- ●ACE inhibitors (benazepril, enalapril) — commonly used together but requires kidney monitoring
- ●Digoxin — furosemide-induced low potassium can increase digoxin toxicity
- ●NSAIDs (anti-inflammatory pain medications) — can reduce effectiveness of furosemide
- ●Aminoglycoside antibiotics — increased risk of kidney damage and hearing loss
Frequently asked questions
Other DCM medications
Important:Never start, stop, or adjust your dog's medication without consulting your veterinarian. The dosages and protocols described here are general references — your vet will determine the right approach for your dog based on their individual condition, weight, and overall health.