The debate about the role of pet food ingredients in copper-related liver disease has been ongoing for years. A small number of dogs accumulate excess copper in the liver, causing copper storage disease, hepatitis, and/or cirrhosis. Various factors have been suggested as causes, including genetics and pet food ingredients. Initial observations of copper storage disease affected only Bedlington Terriers, due to the autosomal recessive trait in the dog’s DNA. However, case reports involving other dog breeds, such as Labrador retrievers, have since emerged. As the number of affected breeds increased, so did the range of possible causes. It remains difficult to directly explain these copper storage problems.
research team with hills pet nutrition They decided to look for patterns in copper levels in the dogs’ livers over time. They used a repository of data existing in records from the kennels of dogs participating in feeding trials.
“Dogs eat a little bit of everything, so we have a really great bioarchive of samples,” said Leslie Hancock, DVM, study co-author and director of clinical nutrition research at Hill’s Pet Nutrition. told Food Industry. Her team published their results in the Journal of the American Veterinary Medical Association.
Data on dogs eating different diets
Dogs participating in Hill’s feeding trials eat a wide range of recipes during a variety of palatability and digestibility studies. Because of this, results were less sensitive to specific brands or recipe formulations or supply chains when compared to pet dogs, which tend to consistently eat the same breed.
“We’re testing Hill’s products, we’re testing competitors’ products, we’re testing global products,” she said. “We have all kinds: canned, dry, fresh.”
Dogs in feeding trials eat a much wider range of products and formulations than most household dogs. This gave Hancock’s team a rare opportunity to examine the correlation between copper levels in dogs’ bodies and in their diet.
“If there are endemic sources or levels of ingredients in dog food, we might be able to see trends in biomarkers in dogs because they were consuming it so widely,” she says. “At least it serves as a baseline.
Previous studies relied primarily on liver biopsies taken for specific reasons, he said, and data on copper levels in the entire population were lacking.
There are fluctuations in copper concentration, but no explanation is given.
Hancock’s team analyzed 336 samples taken during necropsies conducted between 2006 and 2022 and found no clear correlation between copper levels in dogs’ livers and various diets. I couldn’t. Instead, copper levels in dogs’ livers decreased from 2006 to 2011, increased in 2012, decreased in 2013, peaked in 2016, and then began to decline. However, nothing related to raw materials or manufacturing stood out as a direct cause of variation.
There was a peak in one year, but it was not clinically relevant, said associate scientist Madison Amundson. hills pet nutrition said the study’s co-authors. The dogs’ copper levels never exceeded the normal reference range.
Taking genetics into account, Labrador retrievers had lower liver copper levels compared to beagles, but the hybrids were not significantly different from either purebred breed. Nevertheless, copper levels in all dogs remained within safe limits, Amandson said.
Although it did not provide any explanation for copper storage diseases, it certainly opened the way to a rich source of data.
“The Hill bioarchive is a unique item to have as part of our facility,” said Laura Smith Motzsinger, Ph.D., Hill’s study co-author and senior investigator. “There are a lot of possibilities out there. That includes biopsy samples, blood, canine and feline animals. There’s a lot of things there that we haven’t explored yet.”
The paper, which used liver samples from bioarchives, hopes to open the door to other idea-generating projects, she said.
