570 DISEASES OF THE HOESE. 



From experiments already conducted it appears that this disease, 

 formerly supposed to be confined to Manitoba and Minnesota, is 

 more or less prevalent in Kansas, Nebraska, Colorado, Wyoming, 

 Montana, North Dakota, Virginia, Texas, and New York. It also 

 occurs in Europe, having been reported in Germany under the name 

 of infectious anemia and in France as infectious typho-anemia. 



SyTrbptoms. — The disease is characterized by a progressive perni- 

 cious anemia, remittent fever, polyuria, and gradual emaciation in 

 spite of a voracious appetite. It begins to manifest itself by a dull, 

 listless appearance and by general weakness, the animal tiring very 

 easily. This stage is, followed closely by a staggering, swaying, un- 

 certain gait, the hind legs being mostly affected. There is also noted 

 a weakness and tenderness in the region of the loins,, and at the same 

 time the pulse, though weak, stringy, and intermittent, increases in 

 rapidity and may run as high as 70. The temperature may rise to 

 103° F. or higher, remaining high for several days, and then drop- 

 ping to rise again irregularly. Toward the end of the disease the 

 temperature occasionally remains persistently high. The horse may 

 improve for a time, but usually this improvement is followed by a 

 more severe attack than the first. Venous regurgitation is sometimes 

 noticed in the jugular before death. The quantity of urine passed is 

 enormous in some cases. Death finally occurs from exhaustion or 

 syncope. 



The blood shows a slight decrease in the number of white blood 

 cells, while there is a gradual but marked diminution of red cor- 

 puscles, the count running as low as 2,000,000 per cubic millimeter, 

 the normal count being 7,000,000. If the blood is drawn from such 

 an animal, the resulting red clot will be about one-fifth of the amount 

 drawn. Occasionally a slow dripping of blood^tinged serum from 

 the nostrils is observed as a result of this very thin blood oozing 

 from the mucuous membranes. Petechise, or small hemorrhagic 

 points, are sometimes noticed on the nictitating membrane and con- 

 junctiva, while paleness of the visible mucous membranes of the 

 nose and mouth is usually in evidence, although they may have a 

 yellow or mahogany tinge. Often a fluctuating, pendulous swelling 

 may appear on the lower lip, point of elbow, sheath, legs, under the 

 belly, or on some other pendent portion, especially late in the disease, 

 which is indicative of poor circulation, thinning of the blood, and 

 consequent loss of capillary action. 



Lesions. — After death the carcass is found to be very much ema- 

 ciated and anemic, the visible mucosa being very pale. This marked 

 absence of adipose tissue makes the skinning of the animal a difficult 

 task. Subcutaneous and intermuscular edema and hemorrhages are 

 frequently observed, although in many cases it is remarkable to see 

 how few macroscopic lesions may be present. The predominating 



