A series of mysterious dog ailments at Allegan kennels may be the fault of pet foods containing high levels of fluoride, the state’s Toxic Substance Control Commission said today.
The state agency called on pet food manufacturers to voluntarily begin taking steps to prevent high levels of fluoride from being introduced to dog and cat foods.
The unprecedented action follows testing of major brands of dried pet foods which were found to contain an excess of fluoride suspected of causing deformities, mottled teeth and bony growths afflicting dogs in three Allegan County kennels.
“There is a very good chance this is a more widespread problem that went unidentified until the cases in Allegan,” the commission’s executive director, Lawrence Holcomb, said Thursday.
“If people weren’t looking for the bony protrubences, they probably wouldn’t be aware of them. Chronic effects of fluorosis (fluoride poisoning) may not be noticeable for a long time.”
Holcomb said it’s probable the source of all excess fluoride found in the Allegan dogs is from pet foods and pet food additives.
Although state officials said similar problems have not been reported at other kennels, a Wyoming veterinarian told The Press that dogs at a kennel north of Grand Rapids also are suffering from ailments resembling those in Allegan, particularly deformed puppies.
At a press conference in Lansing this morning, the commission announced the establishment of a telephone hot line (517-373-1133 or 373-1134) for dog owners and breeders who want more information.
Holcomb indicated state agencies would continue studying dogs at the Allegan kennels – where 100 animals have died in recent years – before beginning work this fall toward a state standard for pet food fluoride levels.
The state in 1975 imposed the strictest limits in the nation on fluoride contained in feed for cattle and swine, but doesn’t have fluoride standards for pet foods.
Holcomb said he will recommend state legislation setting limits, even though the pet food problem probably is nationwide. He was unaware whether other states limit fluoride levels in pet foods.
“No one has ever taken a serious look at pet foods before in Michigan,” commented Holcomb, who called the levels of fluoride found “alarming.”
State officials earlier said there were no human health problems associated with dog abnormalities at the Allegan kennels. But Holcomb acknowledged some poor persons have been known to consume dog food…
Holcomb said pet owners who feed their dogs partly with table scraps probably can reduce fluoride levels considerably.
State-conducted tests found most dry pet foods were in excess of the 20 parts per million (ppm) fluoride allowed in Michigan livestock feed.
One dry dog food sample had 1,000 ppm. One dog food additive, a bone meal supplement, contained 1,700 ppm fluoride. No canned foods have been tested.
State officials refused to identify which brands of dog foods they tested, but said they would be released later if manufacturers didn’t reduce fluoride levels on their own.
Calcium additives which some kennels and pet owners mix in with dog foods as a mineral supplement – such as bone meal or rock phosphate – had fluoride levels up to 2,000 ppm. Most were in the 500 ppm to 1,500 ppm range.
One dry cat food tested had 420 ppm fluoride.
Holcomb said the source of fluoride in dog foods appeared to be bone meal, although the highest levels are resulting from the calcium phosphate additives, many of which are made from rock phosphate rich in fluoride.
Dead dogs from the Allegan kennels analyzed by Michigan State University’s Animal Diagnostic Laboratory showed fluoride in bone tissue as high as 19 times above normal.
Urine samples also showed “extremely high” levels of fluoride.
Holcomb said that, even if calcium additives in dog foods were restricted, it would be difficult to remove fluoride entirely from pet foods.
“Pet foods are made up of scraps and lots of ground bone meal from chicken, cattle, and swine bones which could contain high levels of fluoride. We just
don’t know how high.”
Chicken feed, for example, is allowed to contain up to 300 ppm fluoride.
“If a chicken had been getting 300 ppm fluoride from the day it was hatched until it was slaughtered and its bone (where fluoride is concentrated) were used in pet foods, it would be difficult to reduce to a very low level the fluoride in dog foods,” Holcomb observed.
State officials said reproductive problems at one of the Allegan kennels – where puppies have been born dead or deformed – is not typical of fluoride poisoning and needs further study.
Water and soil samples at the kennels also are being analyzed by the commission to determine if there are any additional contaminants involved.
Holcomb revealed Friday that there are three landfills within a few miles of the Mori-Brook kennel where reproductive problems in dogs have been reported. He indicated his agency would be testing for any chemicals that might be flowing toward the kennel and possibly contributing to the problem.
Veterinarian Eugene Kuhns, owner of the Wyoming Animal Hospital, said he wonders “if this (fluoride poisoning in dogs) isn’t more widespread and there has been a reluctance of some kennel owners to come forward. I hope this (the commission action) may bring them out of the closet.”
Kuhns was one of the first veterinarians to identify the dog problems at the Wil-O-Lane kennel in Allegan, and has seen similar ailments at a Grand Rapids area kennel he declined to identify.
He said state officials should take a “hard look” at limiting fluoride levels in pet foods, adding he believes there could be human health implications.
Department of Public Health officials earlier had said bone and teeth complaints by some area residents working at or living near the Allegan kennels, however, didn’t appear at this time to be fluoride related.
“The question is why haven’t we seen this nationwide, because the same brands of dog food are distributed all over the country, with more of it sold than baby food,” Kuhns noted.
“I think there’s another factor triggering this, not just the high fluoride levels.”
One of the Allegan kennel dogs that underwent autopsy had small amounts of polybrominated biphenyl (PBB), now believed to be in virtually all Michigan residents following the livestock feed mix-up in the early 1970s.
Kuhns said the bone meal in many dog foods comes primarily from cattle.
About the same time as the PBB tragedy, chronic fluorosis began showing up in Michigan dairy herds due to manufacturers adding rock phosphates to livestock feed, leading to the strict fluoride limitations imposed by the state.
The state didn’t ban fluorides from feed because the state Department of Agriculture argued it would lead to prohibitively higher costs of supplementing livestock feeds.
Rock phosphate became a cheap means of supplementing livestock feed during the Arab oil embargo. Removing fluorides from rock phosphate became increasingly expensive for livestock feed manufacturers with the rising costs of natural gas…
Holcomb also is puzzled why the fluoride ailments afflicting dogs at the Allegan kennel are not being more widely reported.
But he theorized they may have been noticed in kennels first because breeders deal with the same dogs “day in and day out.”
“It’s more likely to find it there. They’re also using large quantities of the same dog food over and over, although we found different lots of the same brands of dog food had varying levels of fluoride.”