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Nafcillin

A representation of Nafcillin

Nafcillin is an antibiotic that is used to treat bacterial infections in humans. But can you also give it to your dog when he's sick? In this article, you'll learn everything you need to know about nafcillin in dogs.

What is nafcillin?

Nafcillin is a penicillin derivative that belongs to the beta-lactam antibiotics. It works by destroying the cell wall of the bacteria and thus killing them. Nafcillin is particularly effective against staphylococci, which often cause skin, bone and joint infections.

Is Nafcillin safe for dogs?

Nafcillin is not licensed for dogs and should only be used under strict veterinary supervision. This is because Nafcillin can have some serious side effects, such as:

  • Allergic reactions, which can lead to skin rash, itching, swelling or difficulty breathing
  • Gastrointestinal complaints, such as nausea, vomiting or diarrhea
  • Liver or kidney damage, which can lead to jaundice, dark urine or elevated liver enzymes
  • Blood count changes, such as anemia, thrombocytopenia or neutropenia
  • Interactions with other medications, such as anticoagulants, probenecid or methotrexate

How is Nafcillin dosed in dogs?

The dosage of nafcillin in dogs depends on the type and severity of the infection. The usual dose is between 10 and 40 mg per kilogram of body weight every 4 to 6 hours. Nafcillin is usually administered as an injection, but can also be taken orally. The duration of treatment varies depending on the pathogen and response to the antibiotic.

What should you consider when giving your dog Nafcillin?

When giving Nafcillin to your dog, there are a few things you should keep in mind to ensure safety and effectiveness:

  • Follow your veterinarian's instructions exactly regarding dosage, frequency and duration of use
  • Inform your veterinarian of any other medications or supplements your dog is taking
  • Monitor your dog for possible side effects or signs of worsening infection
  • Take your dog for regular check-ups and blood tests to check liver and kidney function
  • Do not stop treatment abruptly without talking to your vet

Nafcillin is a powerful antibiotic that is sometimes used in dogs to treat serious bacterial infections. However, it is not approved for dogs and can have serious side effects. Therefore, you should only use it under veterinary supervision and monitor your dog carefully.


The authors assume that a veterinarian should be consulted if an animal is ill and that medication should only be taken after consultation with a doctor or pharmacist. Only an individual examination can lead to a diagnosis and treatment decision.

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