Overview of Asparaginase for Dogs and Cats

Asparagine, commonly known as Elspar®, is an injectable anti-cancer drug used in dogs and cats to help treat lymphoma, or in some forms of leukemia.  

Asparagine is an amino acids important in many body functions. It has been found that many cancer cells require a source of asparagine to survive and thrive. By using a drug that breaks down asparagine, the cancer cells die.

Asparaginase is a drug used to treat various types of malignant cancer. It is harvested from bacteria, primarily Escherichia coli, and will break down asparagine and make it unavailable for use by the cancer cells. This results in cell death.

Over time, the cells become resistant to asparaginase so this drug is commonly used in combination with other drugs to combat cancer.

Asparaginase 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 and Other Names of Asparaginase

This drug is registered for use in humans only.

Human formulations: Elspar® (Merck)

Veterinary formulations: None

Uses of Asparaginase for Dogs and Cats

Asparaginase is primarily used in conjunction with other drugs to treat lymphoma, a specific type of cancer. It is also used to treat some forms of leukemia and sometimes mast cell tumors.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, asparaginase can cause side effects in some animals.

Asparaginase should not be used in animals with known hypersensitivity or allergy to the drug.

The drug should also be avoided in animals with existing liver disease, kidney disease, blood disorders, gastrointestinal problems, pancreatitis or neurologic abnormalities.

Asparaginase may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with asparaginase. Such drugs include prednisone and vincristine.

Asparaginase has been shown to lower blood pressure, induce pancreatitis and cause mild bleeding disorders.

The drug may cause vomiting, diarrhea, breathing problems, weakness and occasionally mild anemia.

How Asparaginase is Supplied

Asparaginase is available in a 10,000 unit/ml concentration in 10 ml vials.

Dosing Information of Asparaginase for Dogs and Cats

Medication should never be administered without first consulting your veterinarian.

Asparaginase is dosed in dogs at 10,000 IU/per square meter of body surface intramuscular or within the abdomen once a week for 2 to 4 weeks. In small dogs, asparaginase can be given intravenous.

In cats, asparaginase is dosed at 400 IU/kg intramuscular or within the abdomen once a week for 2 to 4 weeks.

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.