Copper Storage Disease – Is Your Dog At Risk?
When dog owners begin to notice symptoms such as lethargy, weight loss, weakness, anorexia, diarrhea, and/or vomiting, it can be challenging to pinpoint potential causes, often increasing feelings of panic. Although there are dozens of common canine diseases, some of which are more serious than others, the above symptoms may suggest copper storage disease.
What Is Copper Storage Disease? Is It Dangerous?
Copper storage disease in dogs, also referred to as copper-associated hepatitis (CAH) or hepatotoxicosis, develops following an accumulation of copper. Although copper does play a key role in a number of biological processes, when present in abnormally high amounts, it becomes extremely toxic.
This condition has been increasingly recognized in dogs, and researchers speculate that hereditary defects in copper metabolism have been made worse due to increased environmental exposure. There are also some breeds that face a higher risk than others.
CAH can result in cell death, oxidative stress, and inflammation. The liver is the most commonly impacted organ, and over time, excessive copper storage may result in cirrhosis and death. However, there are steps that dog owners can take in order to combat this disease.
What Causes Copper Storage Disease?
Copper storage disease is primarily a genetic condition that is hereditary in both humans and dogs. Dogs typically absorb copper from their diet and drinking water and when faced with a genetic predisposition, copper can begin to accumulate in the body.
In humans, copper overload is most commonly associated with Wilson’s disease, which causes a genetic mutation in relation to the protein that transports copper for excretion.
In dogs, Bedlington terrier genetic studies have identified COMMD1, a gene associated with abnormal copper metabolism. Other purebred dogs that face a high incidence of copper storage disease include Skye terriers, Dalmatians, West Highland White terriers, Dobermans, American Cocker Spaniels, and Labrador retrievers.
While studying all West Highland White terriers, the overall prevalence is low. However, certain lines of this breed showcase a high prevalence. In Dobermans, approximately 4-6 percent of the population may have chronic hepatitis, which can be caused by copper storage disease.
While a genetic cause of copper storage disease in breeds other than Bedlington terriers is suspected, the current mode of inheritance is not known. For example, Labradors do not suffer from the same encoding issue related to the COMMD1 gene. This illustrates that copper storage disease a different genetic origin across different breeds.
This disease can impact dogs at any age, and although copper storage disease is characterized by the accumulation of copper in the liver in all breeds, the severity of the disease does exist between breeds. There is also a higher prevalence in females than males.
How to Spot the Symptoms of Copper Storage Disease
Since copper storage disease is a chronic condition, it is typically diagnosed in dogs between two and six years of age. While it is possible to spot symptoms in younger dogs, acute presentations of copper storage disease are rare.
Typically this disease develops in various stages. When it is considered to be a subclinical disease, the condition is presented in the dog’s body or liver, yet it is not yet detectable based on any abnormal signs. Since this disease is progressive in nature, symptoms are most often reported among middle-aged and older dogs.
Although rare, when dogs experience acute copper storage disease, this is most frequently seen among young dogs. In this case, the death of liver tissues may result in a release of stored copper into the blood. Symptoms may include:
- Dark urine, anemia
- Jaundice, vomiting
Chronic signs include the same symptoms as above, in addition to:
- Possible nervous system dysfunction
- Excessive thirst
- Abnormal swelling (due to fluid buildup)
- Black stools
- Weight loss
How Are Dogs Diagnosed?
In many cases, dogs suffering from copper storage disease appear to be healthy but showcase high liver enzymes when bloodwork is taken. In other cases, it is clear that something is abnormal and that a dog is sick.
It’s important to note that susceptible breeds can have liver disease from other causes, which is why it’s imperative that dog owners work with their veterinarian to identify the specific root cause.
The first step is to perform lab work, including a complete blood count and urinalysis. If issues with the liver are detected, the next step is to perform a liver biopsy. This will determine copper levels in the liver’s tissue and if necessary, an ultrasound may be required to better understand the current condition of the dog’s liver.
Once Detected, Can Copper Storage Disease Be Treated?
If it is found that a dog’s liver contains an excessive level of copper, the goal will be to reduce existing copper in order to prevent further buildup.
A treatment plan typically includes both medications and dietary changes. Penicillamine, for instance, binds to copper in order to help the dog more easily excrete it. Dogs will be treated on a case-by-case basis depending on the severity of their condition.
Supplements such as zinc or milk thistle may be recommended in order to reduce copper absorption; and for dogs taking penicillamine, vitamin B6 supplementation is recommended.
Ammonium tetrathiomolybdate (TTM) may also be an effective treatment, as it has proven to be an effective treatment for Wilson’s disease. In this study, ten dogs with CAH were treated with TTM for 12 weeks. Eight of the ten dogs showcased decreases in copper at six weeks and at 12 weeks.
There are a number of therapeutic diets available for dogs suffering from liver disease. It is important that each dog’s situation is individually evaluated for the optimal nutritional management of copper storage disease. It may also be necessary to have the household’s water tested to determine copper levels.
It is important to note that if copper storage disease is left untreated, it will likely be fatal to dogs. The goal is to intervene as soon as possible in order to reduce damage to the liver and prevent future complications.
Dog owners should take a proactive approach, especially those who own susceptible breeds.