Mineral Poisons Affecting Stock

New Zealand Journal of Agriculture, Volume 72, Issue 1, 15 January 1946, Page 1

Mineral Poisons Affecting Stock

INSTANCES of stock losses through poisoning by arsenic, lead, zinc, and other substances widely used in farming are reported from time to time. Causes and prevention of such poisoning have been previously dealt with, but in the following article, D. H. Le Souef, Veterinarian, Wellington, lays special emphasis on the dangers to stock through careless handling of common farm poisons.

r T" , HE following is as general a treatment as possible of J. the manner in which stock may gain access to poisons, the symptoms which follow, and the common antidotes and general preventive measures necessary to avoid a recurrence.

Lead

The poisonous forms of lead are litharge, red lead (used in paint and for plumbing), white lead (the common pigment, also used in the manufacture of linoleum and oilcloth), lead arsenate (for spraying fruit trees), and the common metallic lead. Most common source of lead poison is paint. Victims are usually cattle which have an apparent liking for the sweet taste and several cases of poisoning in this way have been reported. Another known case is where two cows died suddenly with acute symptoms arising from arsenate of lead spray. The acute symptoms are colic, convulsions, coma, blindness, coldness of extremities, and passing of hard black faeces. Symptoms may appear after the first day and up to a week from the time of taking the poison. Horses are less susceptible than cattle, pigs, or sheep. Birds, however, are most susceptible to this poison and care must be taken when painting a fowl run or, more particularly, a cage for members of the parrot family which cling to the wire. Treatment, which is likely to be successful if started in good time, consists of a drench of Epsom salts (6oz. to cattle) followed by raw milk and tea or coffee, brewed strong and allowed to cool.

Arsenic

Arsenic occurs in a poisonous or toxic form in weed killers, wheat dressings, and sheep dip. As an oxide (white arsenic) it is almost insoluble and not dangerous,

but the alkaline salts of sodium and potassium are readily soluble. These salts which are mixed with sulphur, soap, and so on to form sheep dip contain about 20 per cent, of soluble arsenic, and 3 per cent, insoluble arsenious sulphide for protection between dippings. ’ Most danger comes from dips. . Dipping rams while hot after droving and allowing stock to graze over pasture contaminated by the overflow from dip and draining pens are known to have been factors contributing to arsenic poisoning.

When poisoning occurs, symptoms of acute gastritis with colic, thirst and great weakness, staggering, straining, and so on are quickly apparent. Death usually occurs within a day or two, but stock sometimes die so quickly that symptoms are not noticed. Cattle and dogs should not be dipped or sprayed in a dip prepared for sheep as the poison may be taken by the mouth or through broken skin.

Directions for mixing dip should be followed carefully. When practicable, administer emetics and purgatives, then, with small animals, milk or egg white. Antidotes are calcined magnesia or , ferric hydroxide, but oil with limewater and linseed tea, which are more likely to be readily available, are effective. The dip, of course, should be washed off the skin.

Zinc

Zinc has caused losses mainly of pigs. Main source of the poison is new galvanised piping from which the lining has been dissolved by the acids of stale milk. The zinc passes into the milk in a soluble form. Pigs have been affected on several farms, the symptoms being swelling and tenderness of the joints, with consequent lameness, loss of condition and death. The antidote for zinc poisoning is carbonate or bicarbonate of soda with demulcents such as raw milk or white of egg. Usually, however, the symptoms are noticed after the trouble has gone too far for effective treatment. Prevention should be the aim. The pipes should be washed out with water. The water must be discarded before pumping the milk through to the pig troughs or holding barrel. These precautions are necessary only while the pipes are new. Once the surface has corroded the danger is past.

Carbolic Acid

Carbolic acid, a coal tar derivative, has frequently caused coal poisoning, mainly in small animals. Dogs and cats are highly susceptible to this drug in its various compoundscreosote, phenol, and so on—which are used as

' disinfectants in skin dressings and for baths.' Symptoms are muscular twitchings followed by paralysis, vomiting, and weakness. Death or slow recovery results." The poison can be absorbed through skin broken by scratching or biting, as with dogs suffering from eczema. Trouble is known to have occurred when carbolic soap was used in giving an enema and again when a disinfectant was put in a bath to kill fleas. The lethal dose through , the alimentary tract is loz. for a horse and 1 to 2 drachms for a dog. The amount absorbed through the skin cannot be measured. Flesh after death by poisoning will give the characteristic smell. . The antidote is Glauber salts (sodium sulphate) administered in solution by the mouth, and, of course, any carbolic on the skin should be washed off with plenty of water. Strychnine Strychnine, as a common rabbit poison, is used by many stock owners. Care should be exercised in handling this poison because of the rapid and serious effect it has on farm animals and, indeed, on the careless rabbiter who does not wash his hands before handling food. At least one farmer is said to have reported his kill after a rabbit drive as “two hundred rabbits, two dogs, and three pigs”! He had neglected to tie his dogs up until all the rabbits had been collected. He had mixed up the strychnine in a . shearing shed, also, and the pigs had had access to the shed. Strychnine is present in the seeds of plants such as nux vomica and is used as a tonic and stimulant in medicine. Used for rabbiting, however, it is a white crystalline powder, coloured pink artificially for safety, and in this form is a much more powerful poison. Symptoms are shown in a powerful stimulus to the nervous system, especially the spinal cord, and tetanic spasms, with curvature of the back, tenseness and quivering of the muscles, are evident. Respiration is arrested and

death occurs from asphyxiation. The antidote which must be printed on the poison container is a strong mixture of mustard and water or a strong salt solution to induce vomiting and so get rid of the poison. This should be followed by strong tea or coffee brewed and allowed to stand. Care must be taken that the fluid does not enter the lungs during a spasm. The remedy must be quickly administered. Tobacco and chlorodyne have been found effective as cures. Caustic Soda Caustic soda has been known to cause poisoning of

pigs and calves. Used in and about cow sheds for cleaning machines and so on it is liable to get into utensils for feeding milk. It is a strong alkali and has a corrosive action, burning the tissues of the mouth and stomach. The antidote is a weak acid solution such as vinegar or lemon which should be given at once, although after burning has occurred healing will be slow. Common Salt Poisoning by sodium chloride or common salt has been reported among cattle, sheep, pigs, dogs, and poultry, the symptoms varying in the different species, but showing mostly in intense pain, . dullness, diarrhoea, vomiting,, collapse, and death. Sometimes the salt has been fed by mistake or has been added to food for medicinal purposes in excess of a safe amount. Trouble has occurred through rock salt becoming dissolved in rain water caught in troughs, and the strong solution drunk by stock (see this. Journal, November, 1939, and January, 1942). Water or food containing 1.5 per cent, and upwards of sodium chloride have caused symptoms in stock and poultry, and should be regarded as dangerous. Treatment consists of giving emetics such as mustard and water, followed by stimulants such as strong tea and demulcents such as milk and white of egg.