Copper is a trace mineral essential to many biological functions in dogs, including enzyme function, red blood cell formation, and antioxidant activity. But too much copper can be toxic—especially to the liver. In the past 20 years, we have observed a troubling increase in cases of Copper Storage Liver Disease, also known as Copper Associated Hepatopathy (CAH). This potentially serious condition results from copper building up in the liver, where it causes cell damage resulting in inflammation and scarring (fibrosis). And if untreated, this damage can lead to irreversible liver failure. Understanding the underlying causes of abnormal copper accumulation is key to preventing and managing this disease.
Historically, Copper Associated Hepatopathy was considered a rare genetic condition, primarily affecting breeds such as Bedlington Terriers, Labrador Retrievers, Doberman Pinschers, Dalmatians, and West Highland White Terriers. In these dogs, it seems that inherited defects in copper metabolism impair the liver’s ability to excrete excess copper through bile. Copper can also accumulate in the liver secondary to other forms of chronic liver disease. Finally, excessive copper intake through diet and supplements can overwhelm the liver’s ability to excrete it, leading to abnormal accumulation in the liver.
The increase in the incidence of CAH in recent years appears to be related to changes in the amount of copper in commercial dog food. Since 1997, the copper content in many dog foods has risen, in part due to the recommendation to switch to adding highly absorbable forms of copper, such as copper sulfate. This shift in the requirements for pet food formulation may explain why we are seeing more cases of copper-associated liver disease, even in breeds not classically considered at risk.
Diagnosing Copper Associated Hepatopathy can be challenging, especially in the early stages. Most affected dogs appear outwardly healthy until significant liver damage has occurred. In most cases, the only early indicator is an elevation in liver enzymes, particularly alanine aminotransferase (ALT), on routine bloodwork. As the disease progresses, more severe signs like weight loss or jaundice may appear.
While a high ALT enzyme level flags an underlying liver problem, it does not indicate the specific cause or disease. An ultrasound of the liver can show subtle abnormalities early in the disease, but also often cannot indicate the cause. Therefore a liver biopsy is essential for making the diagnosis of CAH. Biopsies show the degree of inflammation and scarring, as well as the accumulation of copper in the liver cells. Quantitative measurement of copper in the liver biopsy is also a critical part of the diagnosis to determine whether excessive copper is the cause of the liver damage.
Liver biopsies can be collected with traditional surgery, minimally invasive laparoscopy, or with ultrasound guided biopsies. Surgical and laparoscopic biopsies are preferred in most cases because they allow collection of larger biopsy samples, which are necessary for accurate measurement of copper levels.
Treatment of Copper Associated Hepatopathy focuses on reducing liver copper levels, suppressing liver inflammation, and preventing further damage. Copper chelation, most commonly with D-penicillamine, helps remove excess copper from the liver. This treatment is given for several months to adequately lower copper levels. Antioxidants and anti-inflammatories are administered to reduce ongoing liver damage. Perhaps most critically, affected dogs are transitioned to a low-copper diet to reduce their intake of copper.
The prognosis for copper storage liver disease varies. Dogs diagnosed in the early stages—before significant scarring has developed—can often live normal or near-normal lives with appropriate treatment and dietary management. However, advanced disease carries a guarded to poor prognosis, especially if signs of liver failure are present. This underscores the importance of early detection and, just as importantly, preventive strategies to reduce copper exposure, especially through the diet.
Given the increasing evidence of dietary copper’s role in this disease, dog owners should be proactive about their pets’ nutrition. Choosing a commercial dog food with moderate copper levels and avoiding excessive supplementation is a sensible step—particularly for breeds known to be at higher risk. Unfortunately, most dog food labels do not disclose the exact copper content, making it difficult for consumers to make informed decisions. Veterinarians can guide owners toward safer diet choices and, when appropriate, recommend regular monitoring of liver enzymes in predisposed breeds or dogs with unexplained liver test abnormalities.
Copper Associated Hepatopathy is no longer a rare or isolated condition—it’s a growing concern that appears to be strongly influenced by dietary factors. With heightened awareness, responsible feeding practices, and timely veterinary intervention, we can protect more dogs from this preventable and potentially life-threatening disease.