The More You Know: ALT & Copper Toxicosis?

The More You Know...

At Mythos Poodles, we are committed to using science to deepen our understanding of the world around us—breeding included. Since our inception, we have relied on genetic testing and orthopedic assessments to ensure our dogs embody the quintessential poodle in every way. As proud patrons of Embark for nearly five years, we deeply appreciate the insights their testing provides and are thrilled by their ongoing innovations that offer even greater visibility into ideal pairings.

Occasionally, test results present unexpected findings. When this happens, we conduct thorough research before deciding how to proceed. Two notable cases where this has occurred involve ALT and Copper Toxicosis.

Alanine aminotransferase (ALT) was among Embark’s original tests. When we transitioned from PawPrint Genetics to Embark, we initially found it challenging to explain ALT activity to prospective owners. To bridge this gap, we educated ourselves on the condition to ensure that interested parties could make informed decisions.

In May 2024, Embark introduced testing for Copper Toxicosis, a condition frequently associated with ALT in several breeds. Given our prior experience with ALT, we anticipated a similar response to Copper Toxicosis and felt it was important to share our knowledge on both conditions.

Alanine aminotransferase (ALT)

ALT Activity in dogs is harmless because it is simply a genetic trait that affects how veterinarians interpret liver enzyme levels—it does not cause illness or impact a dog's health.

Why is ALT Activity Harmless?

It’s not a disease—it’s just a variation in how a dog’s body naturally regulates ALT (Alanine Aminotransferase), an enzyme found in the liver.
Dogs with this trait have naturally lower ALT levels, but their liver functions normally.
It does not affect a dog’s lifespan, behavior, or overall health—it’s just a useful piece of information for vets.
Breeding a carrier does not create health risks—it only means some offspring may inherit lower baseline ALT levels, which is harmless

How Does It Work?

ALT is an enzyme that helps break down proteins in the liver.
Some dogs inherit a genetic variant that causes their baseline ALT levels to be lower than average.
This means that if their ALT levels rise, vets need to interpret the results differently because their "normal" is lower than most dogs.

Why Does This Matter?

Since ALT is used to detect liver issues, knowing a dog’s genetic ALT status helps vets avoid unnecessary concern. If a dog has this variant, a slightly low ALT level isn’t a problem—it’s just their normal.

How is ALT Activity Tested?

A genetic test can determine if a dog carries this variant. If they do, vets may adjust how they interpret ALT results to ensure accurate health assessments.

Copper Toxicosis

Depending on type, Copper toxicosis in dogs is a metabolic disorder where excess copper either accumulates (builds up) or attenuates (reduces) in the liver. While the latter, known as ATP7A or RETN, is harmless, the former, known as ATP7B can be fatal.

What breeds can be effected by Copper Toxicosis

After speaking with a veterinarian from Embark, we learned that, while copper toxicosis is most commonly linked to breeds like Bedlington Terriers, Dobermans, and Labradors, it can affect any breed—including Poodles—particularly when there’s a genetic predisposition or excessive copper in the diet. For breeders and dedicated pet owners invested in ethical breeding practices, genetic screening is a prudent step. and it is important to share any relevant genetic testing results with your veterinarian and work together to monitor liver health proactively.

Types of Copper Toxicosis
There are two main genetic variants associated with copper metabolism in dogs:

ATP7B (Accumulating Variant) – This variant increases the risk of copper buildup in the liver. Dogs with two copies of this variant are at a higher risk of developing copper toxicosis, while those with one copy may have a moderate risk.
ATP7A & RETN (Attenuating Variants) – These variants help reduce copper accumulation in dogs that also carry the ATP7B variant. While they don’t completely prevent copper toxicosis, they may lessen its severity.

Implications for Breeding

Dogs with one copy of ATP7B should ideally be bred with dogs that do NOT carry the variant to reduce the risk of producing puppies with two copies.
Dogs with two copies of ATP7B are at a higher risk of developing copper toxicosis and should not be bred with another carrier.
Dogs with ATP7A or RETN variants may help mitigate the effects of ATP7B, but they do not eliminate the risk entirely.
Dogs with only the ATP7A variant and not ATP7B carry no clinical concern, therefore, this variant should not impact breeding decisions.

When to Be Concerned

Symptoms of copper toxicosis include weight loss, vomiting, diarrhea, jaundice, fluid buildup in the abdomen, and neurological signs.
Diagnosis is done through genetic testing, blood work, ultrasound, and liver biopsy.
Treatment includes a low-copper diet, medications to bind excess copper, and antioxidant supplements