An alarming new report suggests that the food we give to our dogs is having some unintended consequences. A team of researchers for the past 26 years collecting and analyzing sperm samples from five dog breeds — the Labrador retriever, golden retriever, curly coat retriever, border collie and German Shephard — and found that canine fertility is plunging. And they think they know at least one of the culprits: commercial dog food.

Scientists measured sperm samples from many dogs for the study, which was published in the journal Scientific Reports recently. They found a 2.5 percent decline in sperm motility — or, the sperm’s forward momentum — between 1988 and 1998, and between 2002 and 2014 when several stud dogs with compromised semen were removed from the program, there was a 1.2 percent decline.

Researchers also find high levels of environmental contaminants that have been linked to problems with fertility.

Scientists looked to see if other factors like genetics played a part, but ultimately determined that 26 years was simply too short a period of time for their to be a genetic problem driving it.

Environmental factors are also likely to blame, but the researchers also believe that dog food plays a role. The researchers were able to demonstrate that many of the chemicals found in the sperm of adult dogs, and in commercially available pet foods, were detrimental to sperm function.

Dr. Richard Lea, Reader in Reproductive Biology in the University’s School of Veterinary Medicine and Science, who led the research said in the statement: “This is the first time that such a decline in male fertility has been reported in the dog and we believe this is due to environmental contaminants, some of which we have detected in dog food and in the sperm and testes of the animals themselves.

“While further research is needed to conclusively demonstrate a link, the dog may indeed be a sentinel for humans – it shares the same environment, exhibits the same range of diseases, many with the same frequency and responds in a similar way to therapies.”