Copper Toxicosis (COMMD1) in Bedlington Terriers explained

Bedlington terriers are a cherished breed in the UK but are known to be susceptible to copper toxicosis, a serious hereditary liver condition. Also called COMMD1, this disorder leads to harmful copper accumulation in the liver, causing inflammation, damage, and if untreated, liver failure and death.

Understanding Copper Toxicosis

Copper is an essential micronutrient for dogs, vital in small amounts for healthy bodily functions. The liver plays a key role in regulating copper levels by filtering excess copper and excreting it primarily through bile. However, in copper toxicosis, due to a genetic mutation, this balance is disrupted.

The condition arises from a mutation in the COMMD1 gene that impairs the liver’s ability to excrete copper properly. As a result, copper builds up in liver cells to toxic levels, leading to chronic hepatitis and progressive liver scarring known as cirrhosis. This damage often progresses slowly and symptoms generally become noticeable around three years of age or later.

Breeds Affected and Genetic Background

While copper toxicosis is most commonly associated with Bedlington terriers, crossbreeds with Bedlington ancestry might also inherit the faulty gene. Testing and selective breeding efforts have reduced the prevalence of the condition over recent decades.

The disorder is inherited as an autosomal recessive trait. This means a dog must inherit two copies of the faulty gene—one from each parent—to develop the disease. Dogs with only one copy are carriers and usually healthy but can pass the gene on.

• Two clear (gene-free) parents produce clear puppies.
• Two carrier parents may produce a 25% chance of affected puppies, 50% carriers, and 25% clear puppies.
• A carrier and an affected parent produce 50% affected and 50% carriers.
• Two affected parents produce affected puppies only.

Recognising Symptoms and Effects

Signs of copper toxicosis often appear as the liver becomes significantly damaged. Symptoms to watch for include:

• Reduced energy or lethargy
• Loss of appetite and weight loss
• Increased thirst and vomiting
• Jaundice (yellowing of skin, gums or eyes)
• Abdominal distension due to fluid accumulation (ascites)
• Neurological symptoms in advanced cases

Because symptoms progress gradually, early genetic screening is vital to manage and prevent the condition.

Health Screening and Responsible Breeding

The Kennel Club supports a health screening programme to test Bedlington terriers for the COMMD1 mutation. Testing involves a simple DNA sample, typically collected by a vet, which is sent to approved laboratories for analysis. Results categorise dogs as clear, carriers, or affected.

Breeders can use test results to make informed breeding decisions, avoiding mating two carriers or affected dogs and thereby reducing the disease’s prevalence while maintaining genetic diversity responsibly.

What Potential Owners Should Know

Prospective buyers of Bedlington terrier puppies should always inquire about the health testing status of the parents for copper toxicosis. Supporting breeders who participate in responsible health screenings contributes to reducing this inherited disease in the breed.

Management and Care of Affected Dogs

While there is no cure for the genetic defect, veterinary management includes early diagnosis, regular liver monitoring, and dietary adjustments such as low-copper diets to reduce liver strain. This can prolong life and improve the quality of life if the condition is caught early.

Regular veterinary check-ups remain important, alongside monitoring for signs of liver disease progression.

Summary and Next Steps

Copper toxicosis in Bedlington terriers is a serious inherited liver condition caused by a COMMD1 gene mutation affecting copper regulation. Understanding the genetic inheritance, recognising symptoms, and utilizing genetic testing are key for responsible ownership and breeding.

If you are a breeder or owner considering breeding your Bedlington terrier, consulting your vet about DNA testing through the Kennel Club health screening scheme is a proactive step. When buying a puppy, always ask for health testing proof to support healthy puppies and breed welfare.

Remember: Responsible breeding and early testing protect future generations of this unique breed from copper toxicosis complications.