CHAPTER XXVIII

INFECTIOUS DISEASES COMMON TO THE DIFFERENT SPECIES OF DOMESTIC ANIMALS


SEPTICAEMIA AND PYAEMIA.--The term commonly used in speaking of simple
septicaemia and pyaemia is blood poisoning.

These infectious diseases are _caused_ by several different species of
bacteria that gain entrance to the tissues by way of wounds. The bacteria
that cause pyaemia are transferred by the blood stream to different organs
and produce multiple abscesses. In septicaemia, the bacteria may occur in
immense numbers in the blood and produce a general infection of the
tissues, causing a parboiled appearance of the liver, heart, voluntary
muscles and kidneys, and enlargement of the spleen. The two forms of
infection are often present at the same time.

[Illustration: FIG. 97.--_Staphylococcus pyogenes_.]

[Illustration: FIG. 98.--_Streptococcus pyogenes_.]

_The forms of bacteria_ that may cause blood poisoning are the
_Staphylococcus pyogenes aureus_ and _albus_ (Fig. 97), _Streptococcus
pyogenes_ (Fig. 98), _Bacillus pyocyaneus_, _Bacillus coli communis_, and
the bacillus of malignant oedema (Figs. 99 and 100). The latter is included
with the bacteria that produce blood poisoning because it is a frequent
cause of wound septicaemia. Subcutaneous, punctured, lacerated, contused
and deep wounds without suitable drainage are the most suitable for the