In this product of sea-weed we have a most valuable remedy for the treatment of a variety of equine troubles. For veterinary purposes the chief preparations employed are the tincture, the liniment, and the ointment, iodide of iron, biniodide of mercury, iodide of arsenic, and iodoform.
Externally, iodine is used as a skin irritant, the tincture being painted on to small areas of skin in the treatment of ringworm and other localized parasitic affections, as well as for the reduction of glandular and other swellings. It is also applied to unhealthy wounds and indolent ulcers. In the form of iodoform it is injected up the nostrils in certain varieties of nasal gleet, and largely used to wounds as an antiseptic dressing. For blistering purposes the biniodide of mercury is commonly employed in veterinary practice. (See Mercury, page 488.)
Internally, iodine is usually prescribed in combination with potassium, iron, or arsenic; the former to excite absorption of effused fluids or glandular enlargements, and the latter as tonics and alteratives. (See Iron and Arsenic, pp. 447 and 453.) Cystic swellings and hydrocele, after the fluid contents have been evacuated, are sometimes injected with tincture of iodine to prevent further accumulations.
Iodine preparations given internally pass quickly into the circulation, and to all the organs. They are rapidly eliminated by the kidneys and the skin, and are to be found in the saliva, urine, nasal mucus, sweat, and in the milk. Iodides too long continued irritate the salivary glands and skin, and all the organs concerned in separating it from the body. This condition is known as Iodism. Taken together the symptoms resemble salivation by mercury, there being a spongy condition of the gums, with increased flow of saliva, defluxion of tears, loss of appetite, and prostration, with wasting of the testicles and other glands. Iodides have the effect of removing the rheumatic poison from subjects of that disease (see Rheumatism, page 21 of this volume), and are given in cases of lead and mercurial poisoning on account of their chemical affinity for those metals and the comparatively harmless compounds resulting.