INFECTIOUS DISEASES OF CATTLE. 471 



millions of cattle west of the Mississippi River; or, altogether, the 

 enormous shrinkage in value of $23,250,000 directly chargeable to the 

 cattle tick. This sum, however, should not be considered in determin- 

 ing the yearly devastation caused by the cattle tick, but rather as an 

 unnecessary reduction in the assets of the infected country. This last 

 loss does not include the decrease in flesh and lack of development of 

 southern cattle occasioned by the parasitic life of the ticks from with- 

 out and by the blood-destroying and enervating properties of the 

 protozoan parasites from within, an additional loss which is so very 

 great that a conservative estimate would place it equal to the loss 

 above mentioned, or $23,250,000. 



The shrinkage in the milk production of cattle harboring many 

 ticks will average 1 quart per day, and the loss occasioned thereby at 

 3 cents per quart for the 875,000 ticky dairy cattle out of more than 

 4,000,000 dairy cattle below the quarantine line would amount to 

 $26,250 per day, or, counting three hundred milking days for each 

 cow to the year, $7,875,000 per annum. The damage resulting to the 

 southern purchaser of northern purebred or high-grade cattle is 

 another item of no small moment. About 10 per cent of all such cattle 

 taken South die of Texas fever even after they are immunized by 

 blood inoculations, and about 60 per cent of these cattle succumb to 

 Texas fever when not so treated. Since they are usually very expen- 

 sive animals and of a highly valued strain of blood, the loss in certain 

 cases is excessive and in others almost irreparable owing to the pos- 

 sible extinction of some particular type especially selected for the 

 improvement of the herd. Thus of the approximate 4,600 of such 

 cattle brought South each year, at least 460 die of Texas fever. The 

 loss entailed would naturally depend on the value of each animal, and 

 since the prices paid for such well-bred cattle range from $100 to 

 $1,000 or even more, it can readily be conceived that the yearly loss 

 from this item alone varies from $46,000 upward. 



Another instance where it is difficult to figure the injury done by 

 the ticks is in the case of death of nonimmune cattle in the tick-free 

 pastures of the South. Such animals are as susceptible to Texas 

 fever as nonimmune northern cattle, and, inasmuch as there are in 

 many States only one out of every four farms infested with ticks, 

 the cattle on the remaining farms will in many cases contract Texas 

 fever when exposed to the fever tick. These losses can scarcely be 

 computed, as the death rate depends so much on the season of the 

 year when exposure occurs and on the age of the animal affected. 

 However, the deaths among such cattle are considerable, although 

 this fact is little appreciated or understood by many outside of the 

 infected area. Thus, if we consider one-tenth of the cattle below 

 the line as nonimmunes which contract the disease on exposure to 

 ticks, and if we figure on the death rate of 25 per cent of these 



