20 
ON HEPATITIS IN THE OX. 
which we have to treat cases of hepatitis in neat cattle. It occurs 
at all seasons of the year, and, when met with in the straw-yard, 
it generally happens to a bullock or cow which was doing better 
than its fellows. It is of most frequent occurrence during the last 
spring, the summer, and first autumnal months. 
Much depends upon the susceptibility of the animal; but warmth, 
fatigue, and large quantities of food of a bad or indigestible quality, 
may be regarded as some of the predisposing causes of this dis¬ 
ease. Cold and wet may also be considered, and with some degree 
of plausibility, exciting causes; as the complaint is frequently met 
with after neat cattle have been turned out of the shed or straw- 
yard in cold rainy weather. At these times they are seen standing 
with their heads turned from the wind, and hanging down; their 
backs up, and the animals shivering with cold. 
The effect upon the bloodvessels may be, that the capillaries be¬ 
come contracted, and the blood has to traverse a shorter circulation 
in the deep-seated ones. The liver may become engorged with 
blood, and inflammation of that organ be the ultimate result. 
Although the production of disorders among animals may mainly 
depend upon atmospherical agency, as it is much implicated both in 
predisposition and excitability ; nevertheless, too luxuriant pastures 
are, perhaps, the most fruitful sources of hepatic attacks. During 
the early part of a genial spring, while the grass remains succulent 
and retains its laxative qualities, cases of hepatitis are not of fre¬ 
quent occurrence; but they become prevalent as the season ad¬ 
vances. As vegetation progresses, the herbage acquires an exube¬ 
rant supply of stimulating nutriment, which may require greater 
powers of assimilation, and, in order to accomplish this, the diges¬ 
tive organs are called into an increased action. 
As the liver is principally involved in chylification, and in the 
expulsion of the excrementitious parts of the food, any additional 
quantity of nutriment taken into the stomachs requires a corre¬ 
sponding supply of bile to propel it through the alimentary canal; 
and, in order to furnish the intestines with that fluid of a proper 
quantity and quality, an increased biliary secretion must, necessa¬ 
rily, be called into action, which may disturb the circulation of the 
hepatic vessels, and excite a sub-acute inflammatory action in the 
parenchymatous substance of the liver. The venous blood may, 
at such times, be of too rich a quality, which may induce conges¬ 
tion in the penicilli, and derangement of function and inflammation 
of the organ may become a necessary consequence. 
In the milch-cow, the first symptom of this malady is a slight 
diminution in the usual quantity of milk, and, after it has stood 
the proper time in the lead, and drawn from the cream, the latter 
frequently presents a ropy appearance, and has a saltish taste. As 
