556 DISEASES OP THE HOBSB. 



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 received 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 be ex- 

 amined microscopically, it may be found to present a normal ap- 

 pearance ; 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 ob- 

 served will not easily be forgotten. If the parasite has not been 

 discovered in the blood for some days, the symptoms mentioned above 

 may be the only ones noticed, and, as a rule, when treated with febri- 

 fuges, 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 examination well-marked symptoms are found; the skin is 

 hot, the temperature more or less elevated — 101.7° to 104° F. ; the 

 pulse full and frequent — 56 to 64 beats per minute; the visible mu- 

 cous 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 an- 

 imals. 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 lachrymation and a 

 little mucous discharge from the nostrils. Occasionally at this period 

 of the disease the submaxillary glands may be found enlarged and 

 perhaps somewhat tender on manipulation. One symptom is mark- 

 edly absent, namely, the presence of rigors or the objective sign of 

 chilliness. 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 present also at this stage of the disease some swelling of the 

 sheath. 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 gradu- 

 ally disappear during the period of apyrexia. After the fever and 

 the accompanying symptoms have for the second time been present 

 for some days — ^the period varying from one to six — the animal is 

 found to have lost the dull, dejected appearance and to look bright. 



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