574 DISEASES OF THE HORSE. 
Symptoms.'—The invasion of this disease when contracted natu- 
rally is usually marked by symptoms of a trivial character; the skin 
feels hot, and there may be more or less fever; there is also slight 
loss of appetite, and the animal appears dull and stumbles during 
action; early a symptom sometimes appears which may be the first 
intimation of the animal’s indisposition, and which, as a guide to 
diagnosis, is of great importance; it is the presence of a general or 
localized urticarial eruption. If the blood is examined microscop- 
ically, it may be found to present a normal appearance; but in the 
majority of cases a few small, rapidly moving organisms will be 
observed, giving to the blood, as it passes among the corpuscles, a 
peculiar, vibrating movement, which if once observed will not easily 
be forgotten. If the parasite has not been discovered in the blood 
for several days, the symptoms mentioned above may be the only 
ones noticed, and, as a rule, when treated with febrifuges, the horse 
quickly improves in health and the appetite returns. This condition 
does not last for more than a few days, when the animal is again 
observed to present a dull and dejected appearance, and on exami- 
nation well-marked symptoms are found; the skin is hot, the tem- 
perature more or less elevated—101.7° to 104° F.; the pulse full and 
frequent—56 to 64 beats a minute; the visible mucous membranes 
may appear clean, but the conjunctival membranes, especially those 
covering the membrana nictitans, are usually the seat of dark-red 
patches of ecchymosis, varying in size in different animals. There 
is more or less thirst and slight loss of appetite; the animal eats its 
grain and green grass, but leaves all or a portion of the hay with 
which it has been supplied. At the same time there are slight 
catarrhal symptoms present, including lacrimation and a little 
mucous discharge from the nostrils. Occasionally at this period of 
the disease the submaxillary glands may be found enlarged and per- 
haps somewhat tender on manipulation. One symptom is markedly 
absent, namely, the presence of rigors or the objective sign of chilli- 
ness. In addition, it will be noted that there is some swelling and 
edema of the legs, generally between the fetlock and the hock, which 
pits but is not painful on pressure, and in case of horses there may 
be also some swelling of the sheath at this stage of the disease. 
When the fever and concomitant symptoms have declared themselves 
for a short period, one thing becomes especially noticeable in every 
animal attacked, namely, the rapidity with which it loses flesh. If 
the blood has been examined microscopically during the second 
-period of fever, at first a few parasites will have been observed in 
it, which day by day increase in number and reach a maximum, 
where they remain for a varying period, or at once suddenly or 
1 This summary of symptoms is based upon work by Lingard. 
