110 DISEASES OF THE Hoa. 
Causes: ‘Season and locality; it is more preva- 
lent in the cold weather than in summer; sudden 
variations of temperature, especially if it is wet; 
particular states of the health, it being more liable 
to attack animals weakened by previous disease. 
It is sometimes the result of catarrh and sore throat 
especially if the animal is exposed to cold and wet 
while suffering from these diseases. It is caused 
by direct irritation, such as medicinal liquids and 
gases which find their way into the bronchial 
tubes and thence into the tissue; from wounds or 
portions of fractured ribs penetrating the sub- 
stance of the lungs; it is also the result of foul air 
and is sometimes caused from the so-called epizoo- 
tic influences or agents and from pulmonary con- 
gestion. - 
_ Symptoms: Pneumonia is usually ushered in 
by a chill, followed by fever, difficult short breath- 
ing, cough and, if the animal is forced to move, will 
show signs of pain and in some cases will squeal. 
Occasionally the symptoms of the disease are pre- 
ceded by general uneasiness, dulness, loss of ap- 
petite, and more or less fever, when, as the disease 
advances, the pulse will increase in frequency and 
will often reach from one hundred and twenty to 
one hundred and fifty per minute. The cough is 
often very troublesome, dry at first, but as the dis- 
ease goes on it will become softer. It is a cough 
which brings no relief to the animal; but when the 
mucus begins to form and the animal can bring 
some up it then gets relief. About this period if 
the fever abates the animal moves about and takes 
