:\IORBID ANATOMY 245 



autumn, the general symptoms are similar to those of the acute 

 type except they are not so severe and are prolonged for a 

 greater length of time. The parasite is of the spherical or 

 coccus form. The general symptoms are not manifested 

 unless the temperature goes above 103° F. Hemoglobinuria 

 is not observed in this type. Cattle which have passed 

 through an acute type owing to the heated season may have a 

 relapse in the form of a mild type in the fall. The essential 

 difference between the two types is found in the different 

 stages of the parasite circulating in the blood. Unless the 

 temperature is taken and the blood carefully examined, mild 

 types of Texas fever would be either overlooked or mistaken 

 for any one of a variety of disorders common among cattle. 



§ 184. Morbid anatomy. Cattle which die of Texas 

 fever undergo post-mortem changes very rapidly. For this rea- 

 son the description of lesions made some hours after death mav 

 be misleading. 



Externally the animal presents nothing abnormal or char- 

 acteristic of the disease. Rareh- dried bits of blood may be 

 found and also some small slightly elevated areas of a bluish 

 color. The skin between the thighs, upon and about the udder 

 and possibly elsewhere may iiave cattle ticks attached. It is im- 

 portant under ordinary circumstances to look for this parasite. 

 The subcutaneous tissue may be more or less j'ellow in color. 

 Oedema of the subcutis over the ventral portion of the body 

 has been observed. The muscles are usually normal in appear- 

 ance although frequently they are pale. 



Very slight if any lesions have been recorded as occurring 

 in the central nervous system and lungs. Blood extra\'asa- 

 tions usually occur beneath the skin and endocardium espe- 

 cially of the left ventricles. On the external surface the 

 petechiae occur for the greater part along the intraventricular 

 groove near the base. The capillaries of the heart muscle are 

 packed with corpuscles. Parenchymatous and fatty degenera- 

 tion of the muscular fibers sometimes exist. The right ven- 

 tricle is distended with blood either fluid or clotted and the 

 left one firmU' contracted. 



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