Copper Poisoning in Dogs

Copper poisoning in dogs is most often noticed in Bedlington Terriers because they have a sensitivity to copper that is inherited, making this breed susceptible to toxicity with even low levels of copper. Because the only way copper can be removed from the body is through bile, veterinary medical experts believe it is a bile flow disorder that causes certain breeds to be more apt to get copper poisoning. There are several other breeds that also have this sensitivity, although it is not seen as often as in the Bedlington Terrier. These breeds include Doberman Pinscher, American Cocker Spaniel, Keeshond, Skye Terrier, West Highland White Terrier, and Labrador Retriever. However, copper poisoning can happen in any breed.

Copper poisoning is a serious, life-threatening emergency that causes irreversible damage to the liver, which eventually becomes fatal if not treated. Acute copper poisoning is most often reported from accidental overuse of copper salt, which is an ingredient in some parasitic deworming treatments. Chronic poisoning is caused by eating pennies or certain kinds of plants, such as certain types of clover. This causes hepatitis (liver inflammation), major gastrointestinal problems (diarrhea, vomiting, abdominal pain), and dehydration. After three days, the copper starts destroying red blood cells, tissues, and liver, so this can be fatal if not treated in the first day or two.

The symptoms of copper poisoning are usually not evident until the damage is already done to the liver, which cannot be reversed. The symptoms to watch for are:

• Abdominal pain and swelling
• Altered mental state (encephalopathy)
• Anemia
• Appetite loss (anorexia)
• Bleeding from the nose or mouth
• Blood in the urine
• Depression
• Diarrhea
• Disorientation
• Excessive thirst (polydipsia)
• Frequent urination (polyuria)
• Jaundice
• Vomiting
• Weight loss

 Types

• Acute copper poisoning shows symptoms right away and is usually from an accidental overdose from parasite medication
• Chronic copper poisoning is progressive and usually caused by eating certain plants or too much copper in the diet

Although any breed can get copper poisoning from eating certain items or from an accidental overdose of deworming medications, several breeds are more susceptible. This is because they have a copper sensitivity giving them a much lower tolerance to copper.

• American Cocker Spaniels
• Bedlington Terriers
• Doberman Pinschers
• Keeshonds
• Labrador Retrievers
• Skye Terriers
• West Highland White Terriers

Other ways to get copper poisoning:

• Eating Mediterranean clover
• Eating pennies
• Overuse of deworming medication

If your dog is one of the breeds mentioned above, the veterinarian will start them on chelation treatment right away to stop the damage before it gets any worse. A complete physical examination will be done next, including vital signs, reflexes, height, and weight. The veterinarian will need as much information as possible about your dog’s symptoms, medical history, recent illnesses or injuries, and abnormal behavior or appetite.

The veterinarian will need to do some blood tests to find the complete blood count, chemical analysis, liver enzyme and glucose levels, and blood gases. In addition, a urinalysis will be done to check for levels of copper and free hemoglobin (blood) in the urine. The veterinarian may also get a fecal sample to do a culture and look for copper in the feces. The most effective way to get a definitive diagnosis of copper poisoning is by getting a sample of tissues from the liver with a fine needle aspiration. The tissue sample will be examined under a microscope to determine the amount of copper in the liver and how much liver damage has already occurred. Imaging will be done with radiographs (x-rays), and possibly a CT scan, MRI, or ultrasound as well.

If your dog is showing severe symptoms, the veterinarian will admit him to the hospital for IV fluids, oxygen therapy, antibiotics, and observation. The treatment for both acute and chronic copper poisoning is chelation with penicillamine or to excrete the copper in the urine, and zinc therapy after your dog’s copper levels are reduced. This will be done in the hospital so the veterinarian can continue to monitor your dog’s progress. A lifelong treatment of 3 mg of zinc per day can help with liver disease. Your dog will need to be monitored for the rest of his life to check zinc and copper levels in the blood. Vitamin E is often used as a supplement to reduce the damage done to the liver.

When your dog is stable enough to return home, you will need to carefully monitor his health for the next several weeks for the residual effects of copper poisoning. In severe cases, intense treatment will be continued daily for several days, but in many cases, treatment is not successful because the damage is irreversible. You will need to return to the veterinarian every few months for liver enzyme tests.