Penicillin G for Dogs and Cats

Penicillin G for Dogs and Cats

penicillin g for dogs and catspenicillin g for dogs and cats
penicillin g for dogs and catspenicillin g for dogs and cats

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Overview of Penicillin G for Dogs and Cats

  • Penicillin G, common vet prescriptions known as Crystacillin® or Flo-Cillin®,  is an antibiotic used to treat and prevent bacterial infections in dogs and cats. This is a natural penicillin and is cultured from the bacteria Penicillium chrysogenum.
  • As with similar penicillin drugs, penicillin G kills bacteria by inhibiting production of the bacteria cell wall. Other related drugs include ampicillin, amoxicillin, and ticarcillin.
  • Many bacteria develop resistance to penicillin G.
  • Penicillin G is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

Brand Names and Other Names of Penicillin G

  • This drug is registered for use in humans and animals.
  • Human formulations: Penicillin G Potassium® (Apothecon), Pfizerpen® (Roerig) and various generic preparations
  • Veterinary formulations: Crystacillin® (Solvay), Flo-Cillin® (Fort Dodge), Crystiben® (Solvay), Dual-Pen® (TechAmerica) and various generic preparations

Uses of Penicillin G for Dogs and Cats

  • Penicillin G is prescribed to treat or control infections caused by susceptible bacteria.
  • Infections treated with penicillin G often include wounds, skin infections, tooth abscesses and bladder infections.
  • Penicillin G is not effective against infections caused by viruses or parasites (such as worms).

Precautions and Side Effects

  • While generally safe and effective when prescribed by a veterinarian, penicillin G can cause side effects in some animals.
  • Penicillin G should not be used in animals with known hypersensitivity or allergy to the drug.
  • Penicillin G may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with penicillin G. Drugs may include methotrexate, probenecid and other antibiotics.
  • It is common for animals to develop diarrhea or loose stools following treatment with oral penicillin G because this antibiotic can change the bacterial population of the pet’s intestinal tract. If your pet has diarrhea, notify your veterinarian. Ask if the medication should be changed.

    How Penicillin G Is Supplied

  • Penicillin G is available in 200,000 units, 250,000 units, 400,000 units, 500,000 units and 800,000 unit capsules.
  • Penicillin G is also available in many different injectable concentrations.

Dosing Information of Penicillin G for Dogs and Cats

  • Medication should never be administered without first consulting your veterinarian.
  • In dogs and cats, the typical dose of penicillin G ranges from 10,000 to 25,000 units per pound (20,000 to 50,000 units/kg) two to six times a day.
  • The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.


<!–Antibiotics & Antimicrobial Drugs



<!–Dentistry & Oral Cavity diseases
Dermatology & Integumentary diseases
Hematology & Hemic-Lymphatic diseases
Respiratory & Thoracic diseases



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