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Furosemide for Dogs and Cats

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Furosemide is a prescription diuretic for cats and dogs, approved by the FDA as a treatment for certain conditions, including high blood potassium, high blood pressure, lung fluid retention, kidney disease and congestive heart failure. Consult your veterinarian immediately if you suspect your pet has any of these conditions and talk to them about furosemide for cats and dogs. If your vet prescribes furosemide for your pet, it may be under the brand names Lasix, Salix or Frusemide either in tablet or liquid form.We make it easy to fill that prescription online at Petco’s pharmacy.

Pet prescriptions available to order at Petco

What does furosemide do?

Furosemide works to prevent certain parts of your pet’s kidneys from taking in and absorbing nutrients like sodium, potassium, chloride and water. This helps your pet avoid buildup of excess fluids in their body. Preventing fluid buildup in the lungs or abdomen can help pets with congestive heart failure, liver disease or kidney disease. Use of furosemide will cause more frequent urination in greater amounts as that excess fluid leaves the body.

Because this medication causes frequent urination, we recommend making sure your pet has access to plenty of fresh, clean water at all times so they stay hydrated. Try to avoid giving them this medication before bedtime. Pet parents who are allergic to sulfa medications are also advised to wear gloves when handling this medication.

As with any prescription pet medication, you will need to consult your pet’s veterinarian with any questions related to the appropriate furosemide dosage for dogs or cats. Your veterinarian will prescribe your pet diuretics based on their body weight and the issue causing the need for treatment.

Is furosemide safe for my pet?

For cats and dogs, diuretics are usually the cornerstone of their treatment plan if they are suffering from congestive heart failure. It’s approved by the FDA for use in dogs and cats when prescribed by your veterinarian. However, there are some precautions to keep in mind, as not all pets will react to the treatment in quite the same way.

For example, if your pet is hypersensitive or suffers from diabetes, they should avoid taking furosemide. If your pet is allergic to the drug, suffers from liver disease or is unable to adequately produce urine, they should not be using furosemide. You’ll want to avoid giving diuretics to pets who are pregnant or lactating. If your pet has kidney failure or is susceptible to dehydration because of vomiting or diarrhea, don’t give them furosemide. Always be sure to follow your vet’s instructions when administering the drug, as there have been some reported cases of pets who were given more than the recommended dosage experiencing hearing loss or anemia. If you think your pet may have taken too much medication, call your vet or the Pet Poison Hotline as soon as possible.

When administering prescription diuretics for dogs or cats, monitor their electrolyte and blood sugar levels, as well as their general hydration. Depending on your pet’s age and weight, your vet may also want to monitor their blood pressure to ensure the medication is working properly.

How long does furosemide take to work?

Furosemide can be administered orally or intravenously. Pets who require the drug for long-term maintenance usually take it orally. Within minutes of administering the drug, your pet will begin to feel the effects, and you will begin to notice the medication taking full effect within 1 to 2 hours. It is a short-acting medication and will generally stop working within 24 hours.

If your vet recommends your pet take furosemide orally, it’s available in both tablet and liquid forms. As with many other pet medications, it can be given to your pet on its own. However, if you begin to notice your cat or dog exhibiting symptoms of an upset stomach or vomiting, consider giving them a treat or food along with future doses. You can also consider putting it in a pill pocket.

Take care to ensure you administer the drug exactly as prescribed by your vet. If you happen to miss giving them a regular dose, give it to them as soon as you are able. If it’s too close to the time of their next dose, don’t double dose—just wait and return to the regular schedule.

What are the side effects of furosemide for dogs and cats?

Consult your veterinarian about the potential side effects for your pet. The most common furosemide side effect in dogs and cats is increased urination, both the amount and how often they urinate. Other possible side effects can include:

  • Dehydration
  • Loss of appetite
  • Electrolyte disturbances
  • Increased water intake
  • Increased sensitivity to light
  • Lethargy
  • Restlessness
  • Increased heart rate
  • Tilting of the head
  • Reduced ability to hear
  • Constipation
  • Vomiting
  • Diarrhea
  • Allergic reactions
  • Increased blood sugar
  • Anemia
  • Seizures

There are also some drug interactions for furosemide to be aware of. Inform your vet of all medications and supplements your pet is currently taking. If your pet is taking one of these medications, you should discuss it with your vet before giving this diuretic to your dog or cat:

  • ACE inhibitors
  • Aminoglycoside antibiotics
  • Amphotericin B
  • Aspirin
  • Atracurium
  • Cisplatin
  • Corticosteroids
  • Digoxin
  • Insulin
  • Nondepolarizing muscle relaxants
  • Probenecid
  • Salicylates
  • Succinylcholine
  • Theophylline
  • Tubocurarine

If these are taken together with furosemide, side effects in dogs and cats can include dehydration, low blood potassium levels and other potentially harmful reactions.

You can shop for Petco’s dog health and wellness solutions to help make your pup more comfortable. You can also find cat health and wellness solutions, including supplements, calming aids, allergy relief, hairball control and more at Petco.

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Reviewed by Dr. Whitney Miller, DVM, MBA, DACVPM

As Petco’s Chief Veterinarian, Dr. Miller is the lead veterinary subject matter expert, overseeing the company’s standards of excellence in animal care and welfare, growth in pet services and much more. Dr. Miller leads Petco’s medical team, supporting over 200 full-service hospitals and mobile vaccination clinics operating in over 1,000 Petco Pet Care Centers nationwide