DISEASES OF ANIMALS 



121 



This and other intestinal parasites are 

 best prevented by a frequent change of 

 pasture and by avoiding the use of wet, 

 improperly drained pastures. 



Warble flies appear from June to 

 September and lay their eggs on the 

 skin, from which they are licked off by 

 the cattle and the grubs on hatching 

 bore through the tissues of the body, 

 finally appearing under the skin. Upon 

 reaching full size, the grub emerges from 

 the skin and falls to the ground. The 

 chief injury from warble flies is done 

 to the hides and this loss is consider- 

 able. In preventing the attacks of the 

 insect, the backs of cattle may be treated 

 with kerosene, train oil or fish oil. The 

 grubs may also be squeezed out and de- 



killed by spraying with kerosene emul- 

 sion and this remedy has, in a number 

 of localities, given the best results. 



Buffalo gnat (Simulium pecuarum) 

 occurs most abundantly along the lower 

 Mississippi valley, where it breeds in 

 stagnant water and sometimes appears in 

 enormous numbers, driving cattle away 

 from their grazing ground. A plague 

 of flies usually lasts for five or six weeks. 

 Smudges have proved the best method 

 of protecting animals in the field against 

 the Buffalo gnat. 



Mange or scabies i s a disease of cat- 

 tle due to a mite closely related to that 

 which causes sheep scab. The disease is 

 gonerally distributed through Kansas, 

 Nebraska, Colorado, Wyoming, Mon- 



Fig. 69 — TICKS ON CATTLE SKIN 



stroyed or killed by smearing the open- 

 ing in the skin with grease mixed with 

 sulphur. 



The horn fly (Haematohia serrata) 

 has become quite generally distributed 

 over the country. It is smaller than the 

 house fly, but quite closely resembles 

 it. The horn fly appears in swarms and 

 has the habit of collecting on the base 

 of the horns from which fact the name 

 has arisen. They attack cattle on the 

 flanks and shoulders, where they are not 

 easily warded off. A mixture of 2 

 parts cottonseed oil or fish oil and 1 

 part pine tar may be applied to the 

 flanks, back and horns at milking time, 

 in order to keep off the flies. This ap- 

 plication must be repeated every week 

 or 10 days. The swarms of flies may be 



tana and elsewhere. It is first recog- 

 nized by the cattle rubbing themselves, 

 and gradually extends from the shoul- 

 ders back over the body. It is believed 

 that the disease affected buffalo as well 

 as cattle and it has been known in Mon- 

 tana for the past 30 years. The only 

 successful way of treating this disease 

 is by dipping and for this purpose a 

 lime and sulphur dip containing 21 

 pounds sulphur and 16 3 /4 pounds of 

 lime per 100 gallons of water is best. 

 Cattle should be dipped twice in the 

 spring and again twice in the fall, the 

 fall application being more important. 

 The interval between the two dippings, 

 either in the spring or fall, should be 

 about two weeks. During 1906 Peters 



