A number of household and commercial products contain acids in sufficient concentration to produce corrosive burns (coagulation necrosis). Hydrochloric, sulphuric, nitric and phosphoric acids are used in a variety of products purchased for home use. Toilet bowl cleaners frequently contain sodium bisulphide which forms sulphuric acid upon contact with water. Antirust compounds contain hydrochloric acid and oxalates. Substances which contain free halogens (iodine, bromine and chlorine) can also be corrosive.
Acids usually produce a fulminating lesion at the point of contact. The degree of damage is directly related to the concentration of the acid concerned.
Acids produce intense pain and are usually accidentally ingested in diluted form. The mucous membranes are severely affected. Necrotic lesions are grey to black, but nitric acid produces a yellow colour. Inhaled acid vapours produce pulmonary oedema and shock. Eye damage is particularly severe and serious.
External contact should be treated with continuous water irrigation for 10 to 20 minutes. Animals must be prevented from licking themselves and thus extending the lesions to the mouth. In ocular exposure, the eyes should be washed with isothermic isotonic saline for 30 minutes. Initially water may have to be used.
The treatment of acid ingestion is controversial. Alkali, antacids such as aluminium hydroxide and water are generally contraindicated where considerable quantities of acid have been ingested because the resulting exothermic reaction can produce thermic burns. Vomiting is also contraindicated. The treatment of choice is gastric lavage followed by antacid (aluminium hydroxide).
Alkalies produce penetrating liquifaction necrosis of tissues by solubilizing cell membranes. Tissue penetration and chemical reactions between lipids and proteins continues until the base excess of the alkali is neutralized.
The most caustic household products are solid drain cleaners, toilet bowl cleaners, dishwasher detergents and ammonia. Because of the pain associated with exposure, animals generally do not swallow enough material to produce oesophageal lesions.
The main clinical features are severe salivation and marked irritation of oral mucous membranes.
Treatment is directed towards all known routes of exposure including oral, cutaneous and ocular. The administration of acids are contraindicated because of the exothermic reaction. The gastric acid is usually sufficient to neutralise small amounts of alkali ingested from household materials. Washing external areas with copious water is indicated and ocular exposure is treated in the usual way.
Clarke, M.L., Harvey, D.G. and Humphreys, D.J. (1981). Veterinary Toxicology: 2nd ed. Bailliere Tindall, London.
Coppock, R.W., Mostrom, M.S. and Lillie, L.E. (1988). The Toxicology of Detergents, Bleaches, Antiseptics and Disinfectants in Small Animals. Vet. Hum. Toxicol. 30: 463-473.
Temple, A.R. and Veltri, J.C. (1979). Outcome of Accidental Ingestion of Soaps, Detergents and Related Household Products. Vet. Hum. Toxicol. 21: 9-11
