In the majority of cases, cough is a symptom of numerous pathological conditions; sometimes it may be regarded as a disease of itself, because it is the most prominent and unpleasant symptom.

1. In laryngitis, the cough is harsh, rough, and painful; in chronic laryngitis, it is hoarse and paroxysmal.

2. In catarrh, it is slight, occasional, and humid.

3. In bronchitis, it is hard, frequent, and dry in the first stage; soft and moist in the second.

4. In pneumonia, it is short, frequent, and humid.

5. In pleurisy, it is short, dry, and suppressed.

6. In asthma, it is frequent and wheezy, induced by the least exertion, and ending in vomiting.

7. In distemper, there is a peculiar husky cough, apt to end in vomiting, and ushering in bronchitis.

8. The dog may cough from the lodgement of a bit of bone in the throat. This part should always be examined when a patient is suffering from a frequent hacking cough which seems to be induced by some irritation in the throat, as in pharyngitis.

9. Cough of variable character may accompany diseases of the stomach and of the liver, worms, etc.

A cough is frequently the initial symptom of some approaching serious disease of one or other of the respiratory organs; the warning should not be unheeded.

A slight cough induced by exposure to cold may end in a short time by slight mucous discharge, or it may subsequently become associated with other graver catarrhal symptoms.

It is obvious that the treatment must be regulated by two considerations, - the cause of the cough, and the pathological state with which it is allied. The primary disease must first be made out, and then treated as directed in different parts of this work; for it would be in vain to attempt to cure a cough depending on the irritation of worms, for example, without first of all getting rid of the parasites.