Читать книгу Special Report on Diseases of Cattle - Lowe - Страница 62

Lead poisoning of cattle sometimes comes from their having licked freshly painted surfaces and thus swallowed compounds containing white lead. In several instances cattle have been poisoned by silage from a silo painted inside with lead paint shortly before filling. Sometimes cattle eat dried paint scrapings with apparent relish and are poisoned. Cattle grazing on rifle ranges have been poisoned by lead from the bullets. Sugar of lead has been administered by mistake for Glauber's salt. Lead poisoning may be acute or chronic. The fatal dose of sugar of lead is from 1 to 4 ounces. Water drawn from lead pipes or held in a lead-lined tank may cause poisoning.

Symptoms.—The symptoms are generally dullness, lying down with the head turned toward the flank, colic, rumbling in the abdomen, loss of control of the limbs when walking, twitching, champing of the jaws, moving in a circle, convulsions, delirium, violent bellowing, followed by stupor and death. The symptoms generally extend over considerable time but may end in death after 24 hours.

Chronic lead poisoning occasionally occurs in districts where lead mining is the principal industry. The waste products of the mine thrown into streams contaminate the water supply, so that the mineral is taken into the system gradually, and a very small per cent of any of the salts taken into the system in this way is pernicious. Water which contains any salt of lead to the extent of more than one-tenth of a grain to the gallon is unfit to drink. Such water when used continually is likely to produce colic from the resulting intestinal irritation, and in aggravated cases paralysis more or less severe is likely to be developed. A blue line on the margin of the gums, the last symptom, is regarded as diagnostic and its presence as conclusive evidence of the nature of the disorder.

Treatment.—The treatment should first be directed toward removing the cause. A large dose of purgative medicine should be given, and the brain symptoms be relieved by giving bromid of potassium in half-ounce doses every 4 or 5 hours and by the application of cold water to the head. Dilute sulphuric acid in half-ounce doses should be given with the purgative medicine. In this case sulphate of magnesia (Epsom salt) is the best purgative, and it may be given in doses of from 1 to 2 pounds dissolved in warm water. After the acute symptoms have abated, iodid of potassium may be given, in doses of 2 drams each, three times a day for a week.

No treatment is likely to be of avail until the cause is removed.