Anatomical reasons. Gullet, weight of stomach, riding, dystokia.
Symptoms. Tendency to chronicity. Treatment.
In ruminants this is the most common phrenic hernia of a hollow
abdominal viscus. On the right side the gastric and intestinal organs
are separated from the diaphragm by the flat mass of the liver. A
laceration in this region must therefore be extensive to allow of the
protrusion of any abdominal organ into the chest. The left half of the
diaphragm, however, comes in direct contact with the reticulum and any
opening large enough to admit of this viscus is likely to entail hernia
of the second stomach. The lesion is further favored by the fact that
the gullet passes through this part of the diaphragm and is connected
with the stomachs in the furrow between the first and second stomachs.
In case, therefore, that the gullet is violently dragged upon by the
weight of the contents of the overloaded or tympanitic paunch, or when
the animal rises on its hind limbs, in riding its fellow, the foramen
sinistrum is liable to be enlarged by laceration, and the second stomach
most naturally protrudes through the opening. The strain thrown on the
diaphragm in violent abdominal contraction, as in difficult parturition,
is mainly expended on this left half, and the laceration takes place
around the œsophagus, or as in cases reported by Schurinck and
Siedamgrotzky through the aponeurotic portion. The protrusion may be
composed of the second stomach alone, or together with portion of the
paunch as observed by Schmidt in a goat, or of the third and fourth
stomachs as in a case in a bull reported by Baraillé. The edges of the
orifice may show, in recent cases, the fringed or irregular jagged
outline with blood clots and thickening, or in chronic cases the pale,
fibrous, smooth, even outline already described under diaphragmatic
hernia.
The _symptoms_ are like those of other forms of phrenic hernia, in ratio
with its extent. The tendency to survival, and chronicity is greater
than in the monogastric animals, 1st because the entrance of the smaller
viscera is barred by the great gastric masses applied against the wound,
and 2nd by the quiet uneventful life of the ox and the absence of active
work and violent excitement.
_Treatment_ will not differ from that of other forms of phrenic hernia.