INFECTIOUS DISEASES OF CATTLE. 469 



INJURIOUS EFFECTS OF CATTLE TICKS. 



Many cattle owners who have always been accustomed to see both 

 ticks and ticky cattle on their farms are unfortunately not inclined 

 to attach much importance to cattle ticks, and, as a rule, through 

 lack of appreciation of their damaging effects, placidly consider them 

 as of little consequence. That ticks may be detrimental to their hosts 

 in several ways has probably not suggested itself to these stockmen, 

 who are most vitally affected, and it therefore seems necessary to 

 emphasize the fact that, in addition to their relation to Texas fever, 

 they may also be injurious to cattle as external parasites. While 

 the power of transmitting Texas fever is undoubtedly the most dan- 

 gerous property possessed by the cattle tick and is the principal 

 cause for adopting stringent measures in securing its complete eradi- 

 cation, nevertheless there still remain other good reasons for the 

 accomplishment of this achievement. These secondary objections to 

 the presence of ticks on cattle consist in the physical harm they do 

 to the host aside from the production of the specific disease of 

 Texas fever. True, a few parasites may remain on cattle indefinitely 

 without causing any noticeable effect, but it is not uncommon to 

 notice bovine animals on pastures with their hides heavily infested 

 with these pests. In such cases it can readily be seen that the contin- 

 uous sucking of blood causes more or less impoverishment of the 

 circulation. The animal must therefore be fed heavier in order to 

 meet the demands of the parasites in addition to the ordinary needs 

 of the host. If the ticks be removed from the body, the bites inflicted 

 are often distinguished by small inflamed or reddened areas some- 

 what swollen, with perforations of the skin which may allow the 

 entrance of various kinds of disease germs, and showing that more 

 or less irritation of the hide is produced by these parasites. This 

 condition, together with the loss of blood, frequently induces an irri- 

 table state and evidences of uneasiness commonly known as "tick 

 worry," which results in the loss of energy and other derangements of 

 the animal's health. It may in some cases become so pronounced, 

 especially in hot weather, that the animal will lose flesh in spite of 

 good pasturing, thereby reducing the vitality and rendering it more 

 susceptible to the inroads of disease. Moreover, if the infestation of 

 ticks is not controlled, the cattle may be so reduced in condition that 

 growth is retarded, and, in the case of young animals, they may never 

 become fully developed, but remain thin, weak, and stunted — a con- 

 dition that has been termed "tick poverty" — and easily succumb to 

 other diseases as a result of lowered vitality. In milch cows this 

 debilitating influence of the numerous ticks is shown in a greatly 

 reduced milk supply. This should not appear strange when it is con- 

 sidered that some animals harbor several thousand of these blood- 



