ranes, which frequently
involves the lungs. Inflammatory complications also occur in the form of
swellings of the subcutis, tendons, and tendinous sheaths and laminae of
the feet. The causative agent has not been satisfactorily established.
One attack usually protects the animal from future ones of the same
disease, but not always. An apparently complete recovery is sometimes
followed by serious sequelae of the nervous and blood-vessel systems.
Under certain conditions of the atmosphere or from unknown causes, the
disease is very liable to assume an epizootic form, with tendency to
complications of especial organs, as, at one period, the lungs, at
another the intestines, etc.

The first description of influenza is given by Laurentius Rusius in
1301, when it spread over a considerable portion of Italy, causing
great loss among the war horses of Rome and the surrounding district.
Later, in 1648, an epizootic of this disease visited Germany and spread
to other parts of Europe. In 1711, under the name of "epidemica
equorum," it followed the tracks of the great armies all over Europe,
causing immense losses among the horses, while rinderpest was scourging
the cattle of the same regions. The two diseases were confounded with
each other, and were, by the scientists of the day, supposed to be
allied to the typhus, which was a plague to the human race at the same
time. We find the first advent of this disease to the British Islands in
an epizootic among the horses of London and the southern counties of
England in 1732, which is described by Gibson. In 1758 Robert Whytt
recounts the devastation of the horses of the north of Scotland from the
same trouble. Throughout the eighteenth century a number of epizootics
occurred in Hanover and other portions of Germany and in France, which
were renewed early in the present century, with complications of the
intestinal tract, which obtained for it its name of gastro-enteritis. In
1766 it first attacked the horses in North America, but is not described
as again occurring in a severe form until 1870-1872, when it spread over
the entire country, from Canada south to Ohio, and then eastward to the
Atlantic and westward to California. It is now a permanent disease in
our large cities, selecting for the continuance of its virulence young
or especially susceptible horses which pass through the large and
ill-ventilated and uncleaned stables of dealers, and assumes from time
to time an enzootic for