Dogs may be at risk of lead poisoning after researchers found “very high” concentrations of shot in raw pheasant pet food.
Lead is a toxic metal, poisonous to both humans and animals and its effects are particularly concentrated on the nervous system.
Despite the dietary health danger, lead shot can legally be used to kill ground game, such as pheasants, in the UK.
Most pheasants are eaten by people, but some are chopped up and used in pet food.
In a new study, researchers at the University of Cambridge have found that more than three-quarters of 90 samples taken from UK produce had lead concentrations above the maximum residue level (MRL) permitted by law.
They tested three raw pheasant dog foods and found that the average mean lead concentrations were approximately 245, 135, and 49 times higher than the MRL.
The overall average in raw pheasant dog food was found to be 34 times that of pheasant sold for human consumption, which is itself considered too high.
Professor Debbie Pain, from the University of Cambridge’s zoology department, said: ‘We already knew that lead concentrations in pheasant meat sold for human consumption are often much higher than would be permitted in other meats such as chicken, beef or pork.
“However, we were surprised to find that lead concentrations in raw pheasant dog food products were much higher.”
The researchers said this could be because pheasant is usually sold as whole birds or breasts for humans, but minced for dogs.
Grinding can break up the lead shot and create smaller particles in the meat, increasing the chance it will be absorbed into the bloodstream.
Dogs that eat foods with such high concentrations of lead, especially as their main diet, are at risk of health damage, the researchers said.
Puppies are especially vulnerable because young animals absorb more lead than they ingest and because the developing nervous system is particularly affected by the toxic metal.
Nine shooting organizations in the UK have pledged to phase out the use of lead over five years from February 2020, citing concerns for sustainability, wildlife and ensuring a healthy market for game.
The Cambridge scientists said they have consistently found compliance with the voluntary ban to be low, but that a blanket ban in Denmark has proven effective.
A ban on the sale and use of lead shot, along with restrictions on lead bullets, is currently under consideration under the UK’s Reach chemicals regulation.
Publishing their work in the journal Ambio, the Cambridge researchers tested five pheasant-based dog foods.
Three of these were raw meat, one was dried pheasant and partridge, and the other was processed canned pheasant and goose.
Three other equivalent chicken products (raw, dried and processed) were also tested.
Lead concentrations above the MRL were found in dried pheasant product, but at levels below those found in raw meat.
None of the canned chicken or pheasant products contained unacceptable levels of lead.
The researchers said raw dog food is widely available to the UK’s 13 million dogs, and pheasant is sold by 34% of the 50 online raw pet food suppliers they checked, with 71% those who claim that the meat may contain pellets.
Professor Rhys Green, co-author of the study, said: ‘The fact that the majority of the samples of three randomly sampled raw pheasant pet foods had very high lead concentrations and that our recent research into the types of shot used to kill pheasants found 94% are shot with lead, suggesting that this is a much wider problem than just these three products.
“However, some producers may source pheasants that have not been killed with lead, and owners may inquire when purchasing pet food.”