Copper-Associated Liver Disease in Dogs
Excessive copper build-up in the liver can cause liver disease in some dogs. Common breeds of dog that are affected include Bedlington terriers, Labrador retrievers, and Dalmatians, but it is seen in dogs of other breeds as well. While Bedlingtons have a known genetic mutation related to copper excretion, in other breeds we do not know why some dogs accumulate too much copper on diets that other dogs do fine on. Dogs with this disease may seem completely healthy but have high liver enzymes on bloodwork, or can be obviously sick and even jaundiced (with a yellow color to their skin and eyes). The disease is diagnosed and separated from other types of liver diseases by taking a biopsy of the liver and measuring the copper level. It’s important to note that even dogs of the predisposed breeds can have liver disease from many other causes so it’s important to work with your veterinarian to identify the specific cause in each dog.
Once a dog is diagnosed with too much copper in its liver, the goal is to reduce existing copper in the liver as well as to prevent further build-up. Treatment usually involves both dietary changes (low copper diets) and medications (penicillamine) that bind up copper and help the dog get rid of it. Milder cases may be managed mainly with a low-copper diet. There’s not a single best treatment plan for all dogs, so it’s very important to work with your veterinarian to decide on the best approach for each individual dog.
The ideal amount of dietary copper for dogs with copper-associated liver disease is unknown, but likely depends on the amount of copper in the liver, the amount of copper in the previous diet, the time frame over which the copper built up in the liver, and whether or not penicillamine or other medications are being used. Copper can vary almost ten-fold in commercial over-the-counter dog foods and the amount of copper cannot be predicted based on the ingredients or from any information on the label.
Low Copper Diets
There are 2 therapeutic diets designed for dogs with liver disease that are low in copper. However, these diets are also relatively low in protein and moderate to high in fat and may not be ideal for all dogs that need a low copper diet, especially dogs that have other health problems.
Home-cooked diets are another option and offer more flexibility to accommodate other health concerns than therapeutic low copper diets, but the trade-off is higher expense and a much greater time commitment. If you are interested in cooking a low copper diet for your dog, we recommend scheduling an appointment with our Nutrition Service or with another board-certified veterinary nutritionist (www.acvn.org) to ensure that the diet meets all of your dog’s essential nutrient needs for overall health, while still being low in copper.
You may want to have your water supply tested as copper in water can contribute to the copper accumulation in your dog’s liver. For people with a similar condition, recommendations are to avoid water copper concentrations greater than 0.1 ppm. For water higher than this, filters that remove metals or bottled water can be used.
In addition to the main diet and water, other foods fed to dogs with copper-associated liver disease should also be low in copper. This includes treats, supplements, foods used to give pills, and dental chews. For commercial treats, call the company to ask how much copper is in the treat and then use our nutrient converter to easily compare values between what is in the food you were recommended to feed by your veterinarian and the treats.
Human foods that can be good treat options for dogs on low copper diets include cheese, apples, graham crackers, and hard-boiled eggs, but these foods may not be ideal treats for all dogs, depending on their other health conditions. Keep in mind that regardless of whether your dog needs a low copper diet or not, treats and foods outside their regular diet should always be keep to less than 10% of daily calories and cheese especially is high in calories (~100 kcal per ounce).
Many veterinarians recommend supplementing dogs with liver disease with compounds such as s-adenosylmethionine (SAMe), vitamin E, or milk thistle. While there are no data to support their use specifically in copper-associated liver disease, benefits have been shown in some studies of other types of liver damage, such as from chemotherapy drugs and liver toxins. High quality products containing SAMe or milk thistle (silymarin) or both appear to be safe and are unlikely to cause harm; but quality control of dietary supplements can be questionnable, so finding a good quality brand is critical. Your veterinarian can help you find a reliable source for SAMe, vitamin E and milk thistle.
Zinc is another supplement that is frequently used in dogs with copper-associated liver disease. Zinc may reduce absorption of copper from food in the gastrointestinal tract, although how effective it really is remains unclear. It appears to be safe at commonly recommended doses, but can cause gastrointestinal upset in some dogs. Do not give zinc supplementation without talking to your veterinarian first to determine the right dose and if it’s the right option for your pet.
For dogs being treated with the drug penicillamine, supplementation with vitamin B-6 is recommended as penicillamine can bind this vitamin and reduce blood levels which can lead to other health concerns.
How to know if everything is working
If your dog was sick when he or she was diagnosed, then improvement in how he or she feels suggests that the liver is improving. It can be harder to determine if things are working well in dogs that were diagnosed only because they had some abnormal bloodwork.
While regular testing of liver enzymes in the blood can give us some information about the overall health of the liver, it does not always correlate well with the amount of copper in the liver. The best way to assess whether diet and medical therapy is working for your dog is to repeat a liver biopsy and re-measure the copper. Your veterinarian can advise you on the best follow-up plan for your dog.
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October 27, 2022