POISONING BY ACIDS.
Mineral acids.—The mineral acids—nitric, sulphuric, hydrochloric, etc.— when used in a concentrated form destroy the animal tissues with which they come in contact, and in this respect differ from most of the poisons previously described. When taken into the stomach the mucous membrane of the mouth, pharynx, esophagus, and stomach is apt to be more or less completely destroyed. If taken in large quantities death is likely to result so speedily that nothing can be done to relieve the patient, and even if time is allowed and the action of the acid can be arrested it can not be done until considerable and, perhaps, irreparable damage has been done. The mucous membrane with which the acid has come in contact in the esophagus may be destroyed by its corrosive action and carried away, leaving the muscular tissues exposed. The raw surface heals irregularly, the cicatrice contracting causes stricture, and an animal so injured is likely to die of starvation. In the stomach even greater damage is likely to be done. The peristaltic action of the esophagus carries the irritant along quickly, but here it remains quiet in contact with one surface, destroying it. It is likely to perforate the organ and, coming in contact with the abdominal lining or other organs of digestion, soon sets up a condition that is beyond repair. In a less concentrated form, when this is not sufficiently strong to be corrosive, it exerts an irritant effect. In this form it may not do much harm unless taken in considerable quantity. When thus the mucous membrane of the stomach and intestines becomes inflamed pain and diarrhea are likely to result.
Treatment.—Any of the alkalies may be used as an antidote. Most convenient of these are chalk, baking soda, marble dust, magnesia, lime, soap, or plaster from a wall. Mucilaginous drinks should be given in large quantities.
Vegetable acids.—Oxalic acid in particular is corrosive in its action when taken in concentrated solution, losing its corrosive effect and becoming irritant when more dilute. It also exerts a specific effect on the heart, frequently causing death from syncope. Taken in the form either of the crystals or solution it is likely to cause death in a very short time. Failure of heart action and the attendant small pulse, weakness, staggering, and convulsions are the more noticeable symptoms. Acetic acid is irritant to the gastrointestinal tract, and may cause sudden paralysis of the heart.
Treatment.—The action of the acid should be counteracted by the use of alkalies, as advised above, by limewater or lime or plaster given promptly, by protectives to the digestive tract, and by stimulants.
POISONING BY ALKALIES.
The carbonates of potash and soda and the alkalies themselves in concentrated form cause symptoms of intestinal irritation similar to those produced by mineral acids. Ammonia, caustic soda, and caustic potash (lye) are those to which animals are most exposed. The degree of their caustic irritant effects depends on their degree of concentration. When they reach the stomach the symptoms are nearly as well marked as in the case of the acids. The irritation is even more noticeable, and purgation is likely to be a more prominent symptom. If death is not caused soon, the irritation of the gastrointestinal tract and malnutrition will last for a long time.
Treatment.—Treatment consists in neutralizing the alkali by an acid, such as dilute sulphuric acid (1 per cent) or strong vinegar. The administration of such an antidote and its action must be carefully watched during administration. In the chemical change which takes place when the acid and alkali are combined, carbonic-acid gas is liberated, which may be to an extent sufficient to cause considerable distention of the abdomen, and even to produce asphyxia from pressure forward on the diaphragm. Should this danger present itself, it may be averted by opening the flank, permitting the gas to escape. (See "Acute tympanites, or Bloating," [p. 22].) Flaxseed or slippery-elm decoction must be given to sooth the inflamed mucous surface. Opium may be used to allay pain.