Page 590 - The Veterinary Laboratory and Field Manual 3rd Edition

Necropsy guidelines 527

Emphysema

Bacterial putrefaction particularly by clostrid-
ial organisms will produce a large amount of
gas which will give a honeycomb appearance
to affected tissue (Figure A2.18). This should
be differentiated from true emphysema which
is often a feature of clostridial infection. True
lesions are always associated with other signs
of acute inflammation, vascular comprise and
necrosis, such as swelling, haemorrhage and
fibrin accumulation (Figure A2.19). In addition,
Figure A2.16 Thoracic wall, cat. Barbiturate salt gas will collect inside the GI tract resulting in
crystals. Note the fine, grey-white crystals formed post-mortem bloat which can result in post-
on the parietal pleural surface of the thorax. Crystals mortem prolapse of intestines or reproductive
can be found on any serosal surface exposed to bar- tract. This must be differentiated from true bloat
biturate euthanasia solution and are most commonly or prolapse. In true bloat the rumen becomes
seen on the pleura, pericardium or large airways fol- distended with gas and can result in death as
lowing intracardiac injection. Hypercalcaemia. See a result of impaired venous return to the heart
also Online figure 8. Photo: courtesy of Dr J Davies, and compression of lungs and will be attended
University of Calgary, Canada. by obvious signs of pulmonary atelectasis, vas-
cular congestion in the intestines and abundant
oedema in the inguinal region.

Figure A2.17 Pluck, cat. Barbiturate salt crystals.
In this case barbiturate salt crystals have precipi-
tated onto the tracheal mucosa. See also Online
figure 9. Photo: courtesy of Dr J Davies, University Figure A2.18 Liver, bovine. Post-mortem emphy-
of Calgary, Canada. sema. Gas production by bacteria which overgrow
post-mortem produce a honeycombed appearance
to affected tissues. This should be differentiated
from emphysema caused by clostridial infection
which can be diagnostically useful. See also Plate
54. Photo courtesy of Mr R. Irvine, University of
Glasgow, UK.

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