06 | The complete guide to copper-associated hepatopathy in dogs
Confused by copper? Let’s fix that today.
Copper-associated hepatopathy, or CAH, isn’t just a Bedlington Terrier disease - although we classically think of them when it comes to copper storage disease. Actually, many different breeds get CAH, and it causes marked liver dysfunction - requiring often intensive nursing care.
If you want to know more about copper-associated hepatopathies, how they occur, and how to treat them - as well as how to tailor your nursing care accordingly, then this episode is for you.
So what is copper-associated hepaopathy?
CAH is the abnormal accumulation of copper within the hepatocytes in our liver. Where copper accumulates, oxidative stress and damage occurs - ultimately leading to hepatocyte death.
As more and more of these hepatocytes become necrotic, liver function declines - ultimately leading to hepatic dysfunction/failure.
But before we get into that, we need to understand how copper works in the body, and what the liver’s role in this is.
Copper Metabolism
Copper is a trace element which acts as a cofactor (a ‘helper molecule’) within the body, meaning it’s required for many essential metabolic processes. However, free copper can be toxic - as it can lead to formation of reactive oxygen species, causing oxidative damage.
The liver is responsible for storing, distributing and eliminating copper. Normally, it would be absorbed from the patient’s diet, transported to the liver from the GI tract, and processed accordingly.
There are a number of specialised copper ‘chaperone’ genes/proteins that help the liver do this - including ATP7A, ATP7B, and COMMD1. We see genetic disorders affecting the function or number of these proteins, causing inherited disorders of copper metabolism - like in Bedlington Terriers, who are affected by a mutation in their COMMD1 gene.
So back to CAH…
There are several predisposing factors in the development of CAH, including breed, sex, and diet.
Several breeds have been identified as at an increased risk of developing CAH, including:
Bedlington terriers
Labrador retrievers
Doberman pinschers
West Highland white terriers
Skye terriers
Welsh Corgis
Clumber spaniels.
Both labradors and dobermans have been found to have mutations in their ATP7B gene, which is required for copper transport. Bedlington terriers have a mutation in their COMMD1 gene, which causes impaired copper excretion.
Over the last few years, the prevalence of CAH has significantly increased. Potential reasons for this include the amount or the bioavailability of copper in commercial dog foods, and the increased popularity of home-cooked diets.
What signs do we see?
Well, we might not always see clinical signs - in fact, patients can have a long subclinical period, the length of which varies depending on individual genetics, dietary copper intake, and the speed of copper accumulation.
The initial signs are vague and non-specific, and include:
Anorexia
Lethargy
Nausea
Vomiting
Weight loss
Signs of hepatic failure
An acute haemolytic crisis associated with marked hepatic copper release can also be seen, though this is rare, and reported only in Bedlington terriers.
How is it diagnosed?
Like other liver diseases, CAH is diagnosed using a combination of biochemistry and haematology testing, urine analysis, and imaging with hepatic sampling.
Increases in ALT, AST and ALP are seen on biochemistry; as the liver disease progresses and more and more of the liver becomes damaged, GGT increases, and markers of liver function become abnormal.
The changes we see to our bloodwork and our imaging is not specific for CAH - we will see similar changes in chronic hepatitis, for example, as we discussed in episode 5.
The only way to specifically diagnose CAH is with a hepatic biopsy, submitted for quantitative copper analysis - which allows us to document the exact volume of copper present in the sample.
What about treatment and nursing care?
Once we’ve got our diagnosis, we’re going to treat out patient’s CAH by reducing their dietary copper intake, and by giving copper chelating agents to increase copper excretion.
Alongside this, our patients will require supportive treatment, including antioxidants, choleretics, antiemetics, analgesia (if necessary), appetite stimulants and IVFT, alongside treatment of any complications associated with liver failure.
There’s a lot to think about when it comes to nursing these patients, too, including nutrition, fluid balance, monitoring, and supportive care.
Nutrition is a particularly big area to think about - we need to not only provide nutritional support in the hospital during acute illness, but also advise clients on appropriate low-copper foods to continue with at home.
Our patients are often anorexic, have PUPD, and may be vomiting - all of which will affect their fluid balance. So keeping a close eye on hydration parameters and adjusting IV fluids as needed are also important nursing interventions.
There’s a lot to keep an eye on with these patients, especially if they’ve got marked hepatic dysfunction - including vital signs, neurological function, eliminations, nausea, food and water intake, weight, comfort and much more. So tailor the frequency of your checks to your patient, depending on the severity of their disease, and try to group these together as much as you can, to allow rest time.
On top of all of this, there’s the things we do best - our general nursing and supportive care. The importance of this should not be underestimated - so prioritise environmental management, recumbency care, IV catheter care, managing fear, anxiety and distress, TLC and tempting to eat - those little things all add up to make a big difference to our patients.
Did you enjoy this episode? If so, I’d love to hear what you thought - screenshot it and tag me on instagram (@vetinternalmedicinenursing) so I can give you a shout out, and share it with a colleague who’d find it helpful!
Thanks for learning with me this week, and I’ll see you next time!
References and Resources
Merrill, L. 2012. Small Animal Internal Medicine for Veterinary Technicians and Nurses. Iowa: Wiley-Blackwell
Purina, updated. Copper Associated Hepatitis [Online] Available from: https://www.purinainstitute.com/centresquare/therapeutic-nutrition/copper-associated-hepatitus
Tinoco-Najera and Lidbury, 2023. Copper Hepatopathy in Dogs [Online] TVP. Available from: https://todaysveterinarypractice.com/internal-medicine/copper-hepatopathy-in-dogs/
Tufts University Clinical Nutrition Service, 2017. Copper Associated Liver Disease in Dogs [Online] Available from: https://vetnutrition.tufts.edu/2017/10/copper-associated-liver-disease-in-dogs/
