by | Feb 24, 2012 | horses

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 International Fluoride Free
Thank you to Cathy Justus, Dr. Richard Sauerheber PhD, Veterinarian Larry Kelly  
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Dental Fluorosis in Horses
“Baby Doe”
Accompanying Slide Presentation Mottled (Human) Nails. An Early Sign of Fluorosis

Elk Bone Bubbles – Look for the bubbles in the bone along the edges where bone and teeth meet. Do your eyes agree with the idea that the more bubbles your see corresponds with the F level in each jaw bone?
 #2 690 ppmF (fat free) = 920 ppmF (bone ash)
 #1 490 ppmF                   653 ppmF
 #3 280 ppmF                   373 ppmF

Presentation by Dr. Richard Sauerheber, Ph.D. May 10, 2014


Fluoride Poisoned Horses Cathy Justus


Videos: Poisoned Horses


Dr. Richard Sauerheber (B.A. Biology, Ph.D. Chemistry, University of CA, San Diego) Palomar College, San Marcos, CA

December 22, 2012

Professor Cynthia Gaskill, toxicology section chief
Veterinary Diagnostic Laboratory
University of Kentucky
And Ted S Stashak, DVM, MS
Diplomate ACVS

Dear concerned horse caretakers, This letter is written for your information to help clarify recently written statements on ‘fluoride’ consumption in horses. Calcium Fluoride is not a Listed Toxic; Industrial Fluorides are Listed Toxics. The claim by Ted Stashak ( that a dietary limit of ‘60 ppm fluoride’ published for horses is tolerable, based on information presented by the National Academy of Sciences in 1974, has no significant meaning without explanation, and thus grossly misleads horse owners. First, the NAS limit was set for feed, and did not distinguish between toxic fluoride compounds vs. nontoxic natural calcium fluoride. The value is reported on a dry weight basis, meaning it refers to 60 mg fluoride per kilogram of feed. The ppm designation today is mostly widely used for levels in drinking water in water quality reports. 60 ppm industrial fluoride in drinking water would of course be immediately lethal for both man and animals. A blood concentration of 0.2 ppm average occurs from consuming 1 ppm treated water. 60 ppm in water produces a blood fluoride level far in excess of the lethal concentration measured in fluoride poisoned man and animals of 5 ppm. Further, the 60 mg/kg value for feed was an estimate or rule of thumb to be considered as a rough guide, knowing that fluoride from other sources was not included in its consideration, and was merely based on the paucity of information available at the time. (See We now know that water supplies containing natural fluoride from calcium fluoride is always accompanied with sufficient calcium to minimize assimilation of fluoride after ingestion. Calcium is the universally recognized antidote to fluoride poisoning. The environment in which fluoride exists is the greatest factor that determines the toxicity of the ion. In the absence of calcium, fluoride compounds are all toxic calcium chelators and listed poisons on poisons registries. If calcium fluoride were the source for fluoride in the 60 mg/kg feed allowance, then yes this level is considered nontoxic. The lethal dose of pure calcium fluoride required to kill 50% of mammals is so high as to not be measurable. A typical published value is 3,500 mg/kg single oral dose and even then the cause of death is not necessarily due to the fluoride but to the large amount delivered by stomach tube into the research animal. On the contrary, all industrial fluorides lack calcium and are listed toxics, used as insecticides, rodenticides and pediculicides for external use only. If industrial fluorides are sprayed onto horse feed, this is a completely different matter, and the 60 mg/kg limit has no meaning for these fluoride sources without knowing the calcium content of the feed. The LD50 for sodium fluoride or for fluorosilicic acid fluoride (as used in public water supplies without FDA approval) is a mere 120-125 mg/kg single oral dose in test animals because industrial fluoride lacks antidote calcium. These units are carefully listed in this manner by the Merck Index because a unit such as “60 mg/kg fluoride in feed” is too vague, where the total amount of fluoride ingested by the animal is determined by how much feed the animal eats in a single feeding AND how quickly it is eaten AND the calcium level in the feed AND the specific fluoride compound that is present—these variables determine the maximum blood level of fluoride attained during the feeding and therefore how much fluoride the kidneys are able to excrete while the remaining fluoride incorporates chiefly into bone, teeth dentin, brain pineal gland, and aorta. The infusion of industrial fluorosilicic acid into public water supplies that are devoid of calcium, such as the pure snow melt water in Pagosa Springs, Colorado mentioned by Stushak, allows full assimilation of the fluoride ion after ingestion. Horses in Pagosa Springs exclusively consuming this treated soft water developed symptoms of fluoride poisoning with colic, abnormal bone thickening, skin reactions, teeth and hoof abnormality, cancer, and were killed after about nine years while available veterinarians were unable to diagnose the poisoning. Alligators on a farm in Kansas were killed from chronic silicosis of the liver after silicofluoridation of water began, compared to control animals kept on untreated water (see review of the data in the textbook by Spittle, B., Fluoride Fatigue). On the other hand, the ingestion of industrial fluoride by horses and other species in municipal treated water supplies with hard water can be tolerated, depending on the calcium and magnesium content of the water, where calcium is universally recognized as the antidote to industrial fluoride poisoning. Fluoride is a general protoplasmic poison at 0.2 ppm and inhibits DNA repair enzymes involved in cancer protection. Fluoride at this level also causes a slight anemia due to inhibition of iron assimilation by degraded goblet cells in the small intestine in humans. Any anemia in a racehorse, no matter how slight, is not ‘tolerable’. Heart attack incidence in race horses has been rising, responsible for significant numbers of racing breakdowns, and no proof has been obtained that the increasing use of calcium-chelating industrial fluorides in public water supplies is somehow magically un-involved. The U.S. now has an endemic of tooth fluorosis in teens aged 12-16, with a 41% incidence as of 2004, which prompted Health and Human Services to request fluoride in water not exceed 0.7 ppm as an initial attempt to mitigate this widespread fluoride poisoning. Sadly, no distinction as yet has been made regarding the important determinant of fluoride toxicity, the calcium content of the particular water. U.S. Food and Drug Administration. Gaskill published the common belief, that small amounts of fluoride can be beneficial to animals, which has been thoroughly refuted by detailed research in several laboratories raising animals for generations in a zero fluoride environment. These studies confirm that the FDA ruled correctly in 1963 that fluoride is not a mineral nutrient, and addition into drinking water is an uncontrolled use of an unapproved drug. Contrary to the hopes of fluoride promoters and to Gaskill, in 1988 the FDA correctly ruled that fluoride does not strengthen bone, as revealed in careful human controlled clinical trials conducted by the National Institutes of Health. Moreover, the FDA in 1966 banned the sale of any industrial fluoride intended to be consumed in water by pregnant women. No fluoride compound has ever been approved by the FDA to be taken internally in the U.S.  Although sodium fluoride is allowed by prescription, it is not to be prescribed in cities with fluoride treated water supplies.  Sodium fluoride, known to drug manufacturers as Luride, taken internally by prescription is an unapproved drug. In defense of Gaskill, yes there are no data on fluoride levels in drinking water that might be tolerated by horses particularly since the alimentary canal is so different than in other species and because horses drink enough water to cause complete turnover of body water approximately weekly. But this is all the more reason why horse owners should avoid water treated with industrial fluoride. Again, it has no nutritional value of any kind. Finally, the claims that no well-documented cases exist of harm to horses from drinking water containing industrial fluoride, and that in Kentucky fluoridated water is tolerated well by horses, fail to understand that there are no methods to make such assessments in the general horse population in the first place. The incidence of horses suffering heart attacks in the Calgary stampede rose during periods of industrial fluoridation of water supplies, but no publication has printed this because it is not a prospective controlled trial, even though fluoride causes anemia. Barbaro in the Kentucky Derby broke down from bone breakage where fluoride chiefly incorporates, weakening bone at levels that are not yet known in horse bone and ligaments subjected to the most stress force during racing. No one published the fluoride level in Barbaro bone because this can be unethical, and the fluoride level present has no reference in horses for the extent of weakening that would be expected (3,000 mg/kg weakens human bone and accumulates after an average of a few decades of consumption of 1 ppm fluoride water, depending on calcium content). The combined effects of anemia and fluoridated bone on causing mis-steps and bone breakdown in racehorses are not at present quantifiable. In CA, Los Alamitos racehorse breakdowns rose suddenly after silicofluoridation of the Los Angeles basin began. These quarterhorses are housed at the track and only have access to treated water. Most horses seem unaffected, yes, but the increase in the number of those that do have lethal breakdowns after fluoridation began has not been explained due to any other known change. CA’s Zenyatta, raised on well water but consumed fluoridated water at racing venues after 2007, went undefeated until her final race. How can any scientist publish whether fluoride finally accumulated long enough to cause a blood fluoride level sufficient to cause her to race poorly in her final outing? To claim that no racehorse death or poor performance was ever caused by fluoride consumption, knowing that fluoride is a cumulative poison and a calcium chelator, is irresponsible. The fact remains that industrial fluoride is a toxic calcium chelator and that fluoride allergy occurs in a fraction of horses as it does in humans, and after ingestion the fluoride cannot simply ‘hide’ and somehow play zero role in any adverse toxicity. It is in fact impossible for ingested fluoride to exert zero effect when it is an abnormal ingredient in blood and organs. Fluoride is not a listed constituent in normal blood, according to every Clinical Chemistry, Nursing text or Merck Manual ever printed. In the future it would serve horses and horse owners far better if sweeping claims of safety and effectiveness of industrial fluoride in horses were explained in greater detail please.


Richard Sauerheber, Ph.D.



  1. Portland | FLUORIDE, LEAD, ARSENIC, AND MORE IN OUR WATER - [...] of body weight than do humans. The United States leads the world in race horse breakdowns, with Los Alamedos…


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