574 DISEASES OF THE HOESE. 



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 sjniiptoms are found; the skin is hot, the tem- 

 perature more or less elevated — 101.7° to 101° 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 



i This summary of symptoms is based upon work by Lingard. 



