CANINE DISTEMPER 471 
air. There may be areas of collapse or those abnormally filled with 
air. The inflammatory foci of the lungs are usually consolidated. In 
very young animals there may be a fibrinous exudate which is very 
soft and which readily liquefies. The hepatization frequently 
involves an entire lobe. The hepatized parts are frequently studded 
with small suppurating foci, or are diffusely infiltrated with pus. 
The pleura over the affected parts is often inflamed. The bronchial 
glands are swollen or infiltrated with a serous fluid or with pus. 
In the digestive system, the mucous membrane of the stomach and 
intestines, especially that of the small intestine, is hyperemic and 
swollen. It may be covered with a tough mucus and is often sprinkled 
with hemorrhages. In other cases it is very pale, swollen and easily 
torn. Frequently the contents of the intestine are blood stained and 
the mesenteric glands enlarged and edematous. 
The brain is anemic and often there is a serous effusion into the 
lateral ventricles and subarachnoid spaces. In a few cases-there are 
signs of a purely venous, cerebral hyperemia, as for instance, great 
congestion of all the sinuses, venous plexuses and vessels of the pia 
and the appearance on the cut surfaces of the brain of numerous blood 
points which can easily be wiped off. Kolesnikoff found microscopi- 
cally the brain substance, especially the walls of the vessels, infiltrated 
with leucocytes. Krajewski noticed dilation of the vessels, cellular 
infiltration of their walls, filling of the perivascular spaces with 
lymphoid cells and migration of lymphoid cells into the stroma of the 
brain and into the protoplasm of the ganglionic cells. The changes in 
the spinal cord, which are not well marked, consist chiefly of anemia 
and slight edema, especia]ly in the lumbar region. Mazulewitsch 
states that in acute paralysis there are changes in the walls of vessels, 
with an exudate along the vessels and in the interstitial tissue of the 
gray matter of the spinal cord. In chronic distemper, there is a 
localized interstitial myelitis with partial atrophy of the cord. Had- 
den found groups of emigrated blood corpuscles in it. In severe 
cases, according to Trasbot, the spinal cord and its membranes are 
often considerably injected with a sero-fibrinous exudate in and under 
the arachnoid and even into the substance of the spinal cord. 
Among the other changes which have been described we may men- 
tion decrease in the total quantity of the blood of the body, combined 
with a certain degree of hydremia. There may be fatty degeneration 
of the liver and kidneys. The muscular tissue of the heart may be 
