As a devoted pet parent, your dog's health and well-being are of utmost importance. Furosemide for dogs is a medication that could become crucial in managing your canine companion's health. Commonly prescribed for various ailments, such as congestive heart failure, this potent diuretic serves a vital function in sustaining a dog's overall wellness in the face of disease. In this article, we will share expert knowledge on furosemide's application and side effects for dogs, empowering you to make educated choices about your dog's healthcare.

What is furosemide?

Furosemide for dogs, which is commonly referred to as Lasix®, is a potent medication mainly utilized as a diuretic or "water pill". In essence, it aids in eliminating excess fluid from your dog's body by preventing water reabsorption in the kidneys and encouraging increased urination. This is especially beneficial in situations where fluid buildup can lead to harm, such as congestive heart failure.

What are the main benefits of furosemide for dogs?

Furosemide offers several significant benefits for dogs, making it a valuable medication in veterinary care. This diuretic has proven to be effective in addressing various health conditions commonly seen in dogs. By reducing fluid retention and promoting increased urine production, furosemide helps alleviate symptoms and improve overall well-being.

While it is crucial to note that every dog's response to medication may vary, here are some of the main benefits associated with furosemide:

Congestive heart failure management: Dogs with congestive heart failure have secondary pulmonary edema (fluid in the lungs) or ascites (fluid in the abdomen) depending on the type of heart disease. To treat the fluid build-up, we use furosemide to pull the excess fluid in the lungs or abdomen into the bloodstream to then be filtered and excreted by the kidneys.

Kidney disease support: Dogs with kidney disease such as nephrotic syndrome, benefit from furosemide as it will help treat secondary pleural effusion or ascites which is fluid accumulation in the abdomen.

Acute kidney failure treatment: Furosemide for dogs has shown some benefit in improving urine output in those dogs suffering from oliguric or anuric renal failure. These types of renal failure have little to no (respectively) urine output as a result of the disease.

Chronic bronchitis therapy: Commonly, in dogs with chronic bronchitis, furosemide reduces coughing. This may be due to its bronchodilatory properties.

Elevated blood calcium levels (hypercalcemia): Furosemide for dogs is most commonly used in the treatment of hypercalcemia. This drug helps reduce calcium levels by increasing urinary calcium excretion.

It's important to remember that while furosemide offers these benefits in dogs, its usage should always be under the guidance and supervision of a veterinarian. Dosage, duration of treatment, and potential side effects need to be carefully considered to ensure the optimal well-being of your dog.

What are the side effects of furosemide in dogs?

While furosemide can be beneficial for dogs, it's essential to be aware of potential side effects that may occur. Understanding and recognizing these side effects is crucial for responsible pet owners.

The most common side effect of furosemide in dogs is increased thirst and urination. As furosemide is a diuretic, its mechanism of action will stimulate urine production, leading to more frequent urination and urine volume. To reduce the chances of potential dehydration, the body will stimulate the thirst reflex, resulting in excessive thirst.

It's worth noting that administering furosemide to dogs may result in lower levels of sodium, chloride, and potassium in their blood. However, these reductions are typically not clinically significant, and only occur in cases where the animal is not eating properly. If your dog is taking furosemide for a long period, however, it's important to regularly check their potassium levels and be prepared to supplement if necessary and at the discretion of your veterinarian.

Administering a high dose of furosemide or not drinking enough can lead to severe dehydration. This can result in cardiogenic shock, which is characterized by low cardiac output causing symptoms such as weakness or collapse, low blood pressure, and low body temperature.

Often, furosemide in dogs leads to higher levels of kidney levels such as blood urea nitrogen (BUN) and creatinine. If the patient is not exhibiting any symptoms of uremia (such as anorexia or vomiting), mild to moderate increases in kidney levels can typically be disregarded.

FAQs

What are the typical doses of furosemide in dogs?

The typical dose of furosemide for dogs is 1-5 mg/kg of body weight given every 8-24 hours. The dose that is prescribed to your dog will vary based on their disease condition and other factors such as the severity of symptoms. It's important to follow the exact instructions of your veterinarian for safe administration. The maximum recommended oral dose for long-term use is approximately 4 mg/kg every 8 hours.

How can I determine if furosemide is effectively benefiting my dog?

If using furosemide to treat congestive heart failure (pulmonary edema), you should notice less coughing, smoother breathing and a reduced resting/sleeping respiratory rate.


In conclusion, furosemide for dogs is commonly prescribed for conditions such as congestive heart failure, types of kidney disease, hypercalcemia and even chronic bronchitis. Furosemide aids in reducing fluid retention and increasing urine production in dogs, leading to symptom relief and improved overall health. Experiencing an increase in thirst, frequent urination, and electrolyte imbalances are common side effects to be aware of. It's important to note that taking high doses of furosemide in the face of dehydration and without proper fluid intake may result in severe dehydration and potentially lead to cardiogenic shock. When used as directed and under the supervision of your veterinarian, furosemide can be an extremely beneficial and safe medication to use for your dog. If you have any questions, please contact your veterinarian.