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  • Heparin is a substance naturally found in mast cells, which are part of the body's inflammatory system.
  • For medicinal use, heparin is available in calcium and sodium salts. Both versions can be obtained from the intestines of pigs. The sodium salt only can be obtained from lung tissue of cattle.
  • Heparin blocks the formation of clotting factors and blood clots. It does not break down clots that have already formed.
  • This drug is used only as an injection since the oral form is not well absorbed.
  • Heparin is used to treat serious diseases and is typically administered in a hospital setting but may, on rare occasion, be administered in the home setting.
  • Heparin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.
  • This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.

    Brand Names or Other Names

  • This drug is registered for use in humans only.
  • Human formulations: Heparin is known by its chemical name and is available from a variety of manufacturers.
  • Veterinary formulations: None

    Uses of Heparin

  • Heparin is used to treat diseases associated with blood clotting such as disseminated intravascular coagulation and thromboembolic disease.

    Precautions and Side Effects

  • While generally safe and effective when prescribed by a veterinarian, heparin can cause side effects in some animals.
  • Heparin should not be used in animals with known hypersensitivity or allergy to the drug.
  • Heparin should be avoided in animals with severely low platelet counts or uncontrollable bleeding.
  • Heparin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with heparin. Such drugs include aspirin, corticosteroids, insulin, diazepam, tetracycline and certain antihistamines.
  • Since heparin affects the body's ability to clot blood, bleeding is one common side effect.
  • Another adverse effect associated with heparin is a low blood platelet count.
  • In animals receiving high doses of heparin for extended periods of time, kidney damage may occur.
  • Overdoses of heparin, which usually results in excessive bleeding, can be controlled with the administration of protamine. This medication can reverse the effects of heparin.
  • Heparin is typically given either subcutaneously or intravenously. Intramuscular injections should be avoided since they can result in bleeding and significant bruising deep in the muscle.

    How Heparin is Supplied

  • Heparin is available in 1000 unit/ml, 2000 unit/ml, 2500 unit/ml, 5000 unit/ml, 10,000 unit/ml, 20,000 unit/ml and 40,000 unit/ml concentrations. The bottle sizes available are 0.5 ml, 1 ml, 2 ml, 4 ml, 5 ml, 10 ml and 30 ml.
  • Heparin is also available in pre-loaded syringes and pre-mixed fluids in various concentrations and sizes.

    Dosing Information

  • Medication should never be administered without first consulting your veterinarian.
  • In the treatment of disseminated intravascular coagulation, heparin is dosed at 25 to 50 units per pound (50 to 100 units/kg) subcutaneously every 6 to 8 hours.
  • For thromboembolic disease, heparin is dosed at 100 to 250 units per pound (200 to 500 units/kg) subcutaneously every 6 to 8 hours. This dose is adjusted so that the clotting time of the animal is 2 to 2.5 times normal.
  • Heparin use is typically tapered off over 48 hours to prevent a 'rebound' effect.
  • 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.

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