Glanders is a specific contagious disease due to the entrance into the blood of a living germ - Bacillus mallei. This disease is communicated from one animal to another by inoculation or actual contact with the virus only, and not, as many suppose, by simply standing in the same stable with, but at some distance from, a glanderous horse. The old theory that glanders sometimes originated spontaneously from filthy stables, severe and neglected cases of distemper and nasal gleet have long ago been discarded as incorrect. While it is true that any debilitating disease will render the system more susceptible to the contagion, yet when a case of distemper or any other disease terminates in glanders, it is evident that the patient has become inoculated by coming in actual contact with the virus of that disease.

The ways of contagion are numerous. It is often communicated through public watering troughs, hitching posts and from running at large upon the commons. It is not necessary that the virus be taken up by the healthy animal as soon as it has been discharged by the diseased one, but it may become dried upon hitching posts and upon the manger in the stable and remain for several weeks and then be taken up by a healthy animal and be capable of producing the disease.

Symiptoms. - As the disease is most commonly seen in the chronic form, the symptoms are not generally well marked in the beginning. It may make its appearance in the form of a mild attack of catarrhal fever, with only a slight, thin mucous-like discharge from one or both nostrils; in a short time this discharge takes on a whitish, glary appearance, becomes gluey and adheres to the nostril, partly clogging it up if not wiped away. The sub-maxillary glands between the branches of the lower jaw first become swollen and painful, but instead of suppurating as in distemper, they become hardened and remain so throughout the disease. Although a close observer might notice the unthrifty condition, the animal might be able to work on for months or even several years without showing any more definite symptoms and at the same time be capable of communicating the disease to other horses. After some time small, ragged ulcers form on the mucous membrane of the nostrils and the symptoms are very apparent. This is known as the chronic form.

In the acute form the symptoms are the same except that they are developed more rapidly, the disease generally running its course and ending in death in from one to three months. Mules nearly always take the acute form.