Page 464 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Fluoride Chapter | 27 431

VetBooks.ir Shupe et al., 1992). Because of the nature and complexity CONCLUDING REMARKS AND FUTURE
of the disease these dental lesions should not be the sole
DIRECTIONS
criterion for diagnosis. In general, severely affected teeth
appear with brown or black discoloration, may have Animals can be intoxicated with fluoride from its higher con-
enamel defects and show increased wear including expo- centrations in supplemented feed or drinking water. The level
sure of the pulp cavity, which causes pain while chewing of fluoride contamination in drinking water is dependent on
roughage or swallowing extremely cold water. There will the nature of the rocks and the occurrence of fluoride-bearing
be a correlation between lesions on incisor teeth and those minerals in ground water. While in small amounts fluoride is
cheek teeth that form and mineralize at the same time. necessary for teeth and bone development, in higher concen-
Cheek teeth that are abnormally worn cause improper trations fluoride is toxic. Fluoride causes toxicity through
mastication with roughage being difficult for the animal multiple mechanisms. In addition to inhibition of Na/K-
to utilize. The animal will have variable and decreased ATPase, fluoride can induce oxidative stress and modulate
intake and the decreased production, slowed growth, and intracellular redox homeostasis, lipid peroxidation and pro-
general poor health associated with poor nutritional status. tein carbonyl content, as well as alter gene expression and
Animals with chronic exposure to excess fluorides have cause apoptosis. A chronic excess to fluoride can have
dry skin and hair coat. adverse effects on teeth, bones and other body systems.
Acute fluoride poisoning of cattle can result in clinical Diagnosis is based on analysis of feed, water, and bones.
signs of depression, weakness and ataxia with postmortem There is no specific treatment for fluoride toxicosis.
findings of gastroenteritis (Bischoff et al., 1999) and
degenerative changes in the renal tubular epithelium. REFERENCES

Agalakova, N.I., Gusev, G.P., 2013. Excessive fluoride consumption
leads to accelerated death of erythrocytes and anemia in rats. Biol.
TREATMENT Trace Elem. Res. Available from: http://dx.doi.org/10.1007/s12011-
013-9691-y.
Diagnosis of chronic fluoride toxicosis is based upon clinical
Barbier, O., Arreola-Mendoza, L., Razo, L.M.D., 2010. Molecular mechan-
signs, exposure history, dental lesions, evaluation of lame-
isms of fluoride toxicity. Chemico-Biol. Interact. 188, 319 333.
ness and bony lesions and elevated urinary fluoride concen- Bischoff, K.L., Edwards, W.C., Fearer, J., 1999. Acute fluoride toxicosis
trations. Normal cattle urine contains less than 6 ppm in beef cattle. Bovine Pract. 33, 1 3.
fluoride. Animals having recent exposure or continuing Centers for Disease Control and Prevention (CDC), 2001.
release from fluorotic bone will have 15 20 ppm urinary Recommendations for using fluoride to prevent and control dental car-
fluoride (Osweiler, 2004). The biopsy of a rib or coccygeal ies in the United States. MMWR Recomm Rep 50 (RR-14): 1 42.
vertebrae for fluoride analysis, as well as radiographic exam- Dubey, N., Khan, A.M., Raina, R., 2013. Sub-acute deltamethrin and
ination of teeth or bones, may also be helpful. A full post- fluoride toxicity induced hepatic oxidative stress and biochemical
mortem examination should be performed, with attention to alterations in rats. Bull. Environ. Contam. Toxicol. 91, 334 338.
National Research Council (NRC), 2005. Fluorine. Mineral Tolerance of
bone and teeth for both gross and histopathologic examina-
Animals. second revised ed. The National Academies Press,
tion. Various bone samples should be submitted for fluoride
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analysis including metatarsal, metacarpal, rib, pelvis and
Osweiler, G.D., 2004. Fluoride. In: Plumlee, K.H. (Ed.), Clinical
mandible. Normal values for cattle are 400 1200 ppm fluo-
Veterinary Toxicology. Mosby, St. Louis, MO, pp. 197 200.
ride on a dry, fat-free basis. Animals affected with chronic Ranjan, R., Swarup, D., Patra, R.C., 2009. Oxidative stress indices in
fluorosis can contain 3000 5000 ppm fluoride on a dry, fat- erythrocytes, liver, kidneys of fluoride-exposed rabbits. Fluoride. 42,
free basis. Analysis of feed, water or suspect material should 88 93.
also be included. Shanks, D.F., 1997 Clinical implications of volcanic eruptions on live-
There is no specific antidote or treatment for chronic stock case studies following the 1995 and 1996 eruptions of Mt.
fluoride toxicosis. Sources of excess fluoride should be Ruapehu. Proc of the Society of Sheep and Beef Cattle
identified and removed from the diet. With reduction of Veterinarians of the New Zealand Veterinary Association. Massey
University, Palmerston North, New Zealand, 27(1): 1 13.
dietary fluoride to background levels, mild to moderate
Shearer, T.R., Kolstad, D.L., Suttie, J.W., 1978. Bovine dental fluorosis:
bone changes may be reduced and normal bone laid
histologic and physical characteristics. Am. J. Vet. Res. 39, 597 602.
down. Extensive bone lesions will not be remodeled to
Shupe, J.L., Olson, A.E., 1971. Clinical aspects of fluorosis in horses. J.
normal and teeth lesions are irreversible. Symptomatic Am. Vet. Med. Assoc. 158, 167 174.
and supportive care for animals with bone and teeth Shupe, J.L., Olson, A.E., 1983. Clinical and pathological aspects of
changes include providing high-quality easily masticated fluoride toxicosis in animals. In: Shupe, J.L., Peterson, H.B., Leone,
feeds, limited grazing area, and provisions to avoid cold N.C. (Eds.), Fluorides: Effects on Vegetation, Animals and Humans.
or frozen water. For mild fluorotic changes, improving Paragon Press, Inc, Salt Lake City, UT, pp. 319 338.
the diet and grazing may avoid excess wear on the teeth Shupe, J.L., Bruner, R.H., Seymour, J.L., et al., 1992. The pathology of
and reduce mastication problems. chronic bovine fluorosis: a review. Toxicol. Pathol. 20, 274 285.