Side Effects of Dogs Taking Penicillamine

Dalmatians are at risk of developing copper-associated liver disease.
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High concentrations of copper released into a dog's bloodstream can cause an inflammatory disease known as "copper associated liver (hepatic) disease." Bedlington terriers, as well as Dalmatians, corgis, Labs, and dobermans, are prone to this condition, and often are treated with penicillamine, a drug that can cause side effects.

Prescription Overview

Despite its name's similarity to the widely-known antibiotic penicillin, penicillamine is a byproduct of penicillin without having any antibiotic properties. It is a known chelating agent, a chemical compound used to trap or remove heavy metals, like copper, lead, iron and mercury, from the body. Penicillamine is registered for use in humans only, but veterinarians often prescribe it for animals as an "extra-label" (used in a manner not in accordance to approved labeling) drug.

Uses of Penicillamine

Most commonly, penicillamine is used to treat copper-associated liver disease in dogs. Symptoms may include jaundice, pale gums, lethargy, lack of appetite, or an abnormal color of urine. Penicillamine also is used in the treatment of lead poisoning, which may come from lead paint, paint chips or other sources of lead, such as plumbing and roofing materials. The drug also is prescribed for kidney and bladder stones caused by an abnormality in cystine metabolism.

Side Effects

While penicillamine generally is safe when prescribed by a veterinarian, it can cause some side effects, namely nausea and vomiting. Dogs who have allergies or who are sensitive to drugs should not take penicillamine. Interactions with other medications, such as antacids, azathoprine and cyclophosphamide, also can be problematic. Pregnant dogs should not take penicillamine, as it has been known to cause birth defects. Rare side effects include fever, kidney impairment, skin reactions or blood disorders.


Always consult with a veterinarian before giving a dog penicillamine, and always follow dosing directions as prescribed. Generally, the drug is given for several weeks to months as a chelating treatment. The entire prescription always should be given over the course of the treatment. If the dog appears to feel better, do not stop the drug, as it may cause a relapse.