Fluoride: A Serious Health Risk for Cats and Dogs?
Last Updated on Sunday, July 06, 2014 05:46 PM
Published on Friday, July 10, 2009 01:50 PM
Written by Michael W. Fox, DSc, PhD, BVet Med
The Environmental Working Group (EWG) has just released a study
of 10 brands of manufactured dog foods analyzed for fluoride content. Eight had levels that could put dogs at risk from developing bone cancer, thyroid disease and other health problems.
The EWG advises dog owners to avoid dog foods containing chicken by-product meal, poultry by-product meal, chicken meal, beef and bone meal, turkey meal and lamb meal. These "meal" contain ground bone that is the source of fluoride that farmed animals accumulate. The pet food industry should work with government regulators to establish fluoride safety-level limits in pet foods.
Cats may also be at risk from chronic fluoride poisoning when similar cheap ingredients are included in their manufactured dry and canned foods. Thyroid disease is extremely common in cats, a disease in part linked to fire-retardant bromide
compounds in carpets, upholstery, and in contaminated sea foods. Fluoride levels can also be high in canned fish products like salmon and sardines, especially in whole- fish- with- bones, dioxins
being additional contaminants of concern in farmed salmon.
This problem of fluoride contaminating some brands of pet food is compounded by pets being given fluoridated tap water to drink. Providing companion animals with purer water, like reverse-osmosis treated water, is advisable. (Brita-type filters do not remove fluoride). Cooking with fluoridated water simply concentrates fluoride in the food, a point that all pet food manufacturers must consider in addition to the ingredients they use in their manufactured pet foods.
Those dog and cat owners preparing their own pet food and who include ground bone as a source of minerals might consider using alternative calcium supplements if the bone meal they purchase has no labeling as to fluoride (and lead) content. Ground bones from longer-living farm animals like dairy cattle, laying hens, and breeding stock are likely to contain higher levels of fluoride than shorter-living chickens, calves, and lambs. Fluorides accumulate in the body of farmed animals over time from such sources as phosphate fertilizers, phosphate supplements, bone meal and fish meal supplements, and pesticide and industrial-pollution-contaminated pastures and animal feed. The bones, fins, gills and scales of fish are often high in fluoride.
Pet owners preparing raw food diets like the B.A.R.F.
(bones and raw food) should play it safe and use young chickens and other animals and avoid including ground bone from older animals like beef cattle and adult sheep. I would also advise using only the cartilaginous knuckle or joint portions of cattle and sheep that are a source of chondriotin, glucosamine
, and other beneficial nutrients, and not include all of the bones in ground-up raw food diets.
Alternatives to commercially available bone meal (calcium phosphate) include fossilized oyster shell (calcium carbonate), dolomite (calcium magnesium carbonate), and various chelated
and non-chelated synthesized or refined calcium supplements (that contain less lead and probably less fluoride) like calcium citrate, ascorbate, stearate and gluconate, all marketed for human consumption. The questionable amounts of fluoride in calcium supplements may have some margin of safety because calcium supplements and antacids (like calcium rich Tums) can block fluoride uptake in the digestive tract.
Note: Flouride in low doses is an important micronutrient, playing an important role in tooth and bone development and structural maintenance. The European Food Safety Authority has approved the use of calcium fluoride as a human food supplement, (1 mgm daily providing 0.5 mgm fluoride). With around 1 mgm/liter of fluoride in fluoridated tap water, and fluoride coming from other sources, the daily dietary intake for humans and animals alike may be excessive and food-supplementation with fluoride ill advised.
The maximum levels of lead, mercury and cadmium in human food supplements allowed by the authorities in Europe are 3 mgm/kg, 0.1 mgm and 1 mg/kg respectively. "Tolerable" levels for fluoride are 1.5 mgm/day for 1-3 year old children, 2.5 mgm/day for 4-8 year olds, 5 mgm/day for 9-15 year olds, and 7 mgm/day for all over 15 years of age including adults. According to the Linus Pauling Institute, Oregon State University, the US tolerable levels are 2.2 mgm/day for children aged 4-8 and 10 mgm/day for adults. The US government (EPA
) allows a maximum of 4mgm/liter of fluoride in drinking water.
Against these figures, the Environmental Working Group's findings of over 9 mgm /kg in dog food with chicken meal as the primary ingredient (possibly from recycled laying hens) is indeed pause for concern.
It should be noted that such "tolerable" fluoride levels are not acceptable for human patients on kidney dialysis, and cats and dogs with kidney disease are likely to be more prone to fluoride poisoning when impaired renal function means more fluoride retention in the body.
Dr. Michael W. Fox is co-author of Not Fit for a Dog: The Truth About Manufactured Dog and Cat Food. Dr. Fox is a well-known veterinarian, former vice president of the Humane Society of the United States, former vice president of the Humane Society International and the author of more than 40 books on animal care, animal behavior and bioethics. A different version of this article,
"Fluoride in Dog Food: A Serious Health Risk for Both Dogs and Cats?" first appeared at Dr. Fox at Two Bit Dog
. This version is posted with Dr. Fox's kind permission.