Continual ingestion of small amount of fluoride through feed or water leads to fluorosis in animals. The toxic effects are based on amount of fluorine ingested, its solubility. Usually 200-400 PPM of it in dry ration produces disease in bovines. It remains in the rocks in association with phosphates. Soil and water from such areas have high fluorine concentration. Smoke, vapours or dust from industries evolved in production of aluminium, copper, glass, superphosphate, glazed bricks or enamels are also potent sources of its poisoning as they contaminate the crops, grasses and water. Water obtained from deep wells also has high fluorine content. Due to its ingestion, hydrofluoric acid is formed in the rumen resulting in irritation of mucosae. The calcium ions are chelated by fluorine resulting in development of nervous signs and inhibition of blood clotting.
Due to excessive ingestion of fluorine, animals show anorexia, vomition, ruminal stasis, diarrhoea, weakness, muscle tremors, constant chewing movement, dilatation of pupil and hyperasthesia. Such animals collapse and die within few hours. Due to chronic ingestion, mottling and pigmentation of teeth occur. Teeth have pits and become brittle and break easily. The animals reveal lameness, stiffness and painful gait. The bones are enlarged, show exostoses, and pain is elevated on palpation.
In fluorotic areas, incidence of milk fever in recently calved dairy animals is high. Such animals show repeated relapses following treatment with calcium preparations. Similarly incidence of gastrointestinal hypomotility and prolapse of genitalia are also high.
It is diagnosed by clinical symptoms and confirmed by radiological examination. Blood analysis reveals high fluorine content and high serum alkaline phosphatase activity; and by postmortem examination which reveals chalky white and brittle bones, gastroenteritis and spurring and bridging of joints. For therapeutic purposes, animals should be removed from affected areas. They should be given 40-50 g of aluminum sulphate orally once daily for 5-7 days. Similarly, oral feeding of calcium chloride @ 50 g/adult dairy animal daily for 2 months has been recorded to markedly relieve signs of lameness and knee posture but lesions of dental mottling are permanent. Calcium preparation should be given by intravenous route while 2-4 liter of glucose be given parenterally. The use of gastric sedatives is helpful in early recovery.