ca.

_Definition._--Strangles is an infectious disease of the horse, mule,
and ass, seen most frequently in young animals, and usually leaving them
immune from future trouble of the same kind.

It appears as a fever lasting for a few days, and is usually associated
with an abscess formation of lymph glands, especially those under the
jaw, which have a tendency to break on the outside. It usually leaves
the animal after convalescence perfectly healthy and as good as it was
before, but sometimes leaves it a roarer or is followed by the
development of deep-seated abscesses which may prove fatal.

_Causes._--The cause of strangles is infection by direct contact with an
animal suffering from the disease, or indirectly through contact with
the discharges from an infected animal, or by means of the atmosphere in
which an infected animal has been. There are many predisposing causes
which render some animals much more subject to contract the disease than
others. Early age, which has given it the popular name of colt-ill,
offers many more subjects than the later periods of life do, for the
animal can contract the disease but once, and the large majority of
adult and old animals have derived an immunity from previous attacks. At
3, 4, or 5 years of age the colt, which has been at home, safe on a
meadow or in a cozy barnyard, far from all intercourse with other
animals or sources of contagion, is first put to work and driven to the
market town or county fairs to be exposed to an atmosphere or to stables
contaminated by other horses suffering from disease and serving as
infecting agents. If it fails to contract it there, it is sold and
shipped in foul, undisinfected railway cars to dealers' stables, equally
unclean, where it meets many opportunities of infection. If it escapes
so far, it reaches the time for heavier work and daily contact on the
streets of towns or large cities, with numerous other horses and mules,
some of which are sure to be the bearers of the germs of this or some
other infectious disease, and at last it succumbs.

The period of the eruption of the last permanent teeth, or the end of
the period of development from the colt to an adult horse, at which time
the animals usually have a tendency to fatten and be excessively
full-blooded, also seems to be a predisposing period for the contraction
of this as well as of the other infectious diseases. Thoroughbred colts
are very susceptible, and frequently contract st