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FARMER'S CYCLOPEDIA OF LIVE STOCK 



neck even tc the shoulders. The ears, 

 in some cases, swell to the thickness 

 of an inch and affected sheep show 

 pronounced cerebral symptoms. About 

 50 per cent of cases die and those which 

 recover are so badly affected that they 

 are of little value for stock purposes. 

 There are certain areas which are com- 

 monly recognized as dangerous on ac- 

 count of the unusual occurrence of this 

 disease on them. This fact gives some 

 basis to the belief that the disease is 

 due to some poisonous plant. No 

 plant has been found, however, which 

 would cause the symptoms of big head. 

 The trouble has also been attributed to 

 the bites of scorpions, but the local dis- 

 tribution of the disease would not har- 

 monize well with this supposition. It 

 may be an infectious disease of which the 

 micro-organism is unknown. In some 

 respects it resembles the disease com- 

 monly known as geel dikkop, which oc- 

 curs in South Africa, and is there be- 

 lieved to be of infectious nature. In 

 some seasons big head causes the loss 

 of from 20,000 to 50,000 sheep and is, 

 therefore, an important disease in the 

 localities where it occurs. Big head 

 appears mostly in the spring, in April 

 and May, but, according to some sheep 

 raisers has also been observed in the 

 fall. It has been known in the localities 

 where it occurs for the past 30 years. 



Rabies — In sheep, the incubation pe- 

 riod for this disease ranges from 25 to 

 90 days. Symptoms are much the same 

 as those observed in other animals and 

 include restlessness, bleating, stamping 

 of the feet, and the tendency to bite. 

 (See under Diseases of Dogs.) 



Parasitic ictero-hematuria — This dis- 

 ease, also known as carceag in Europe, is 

 due to a minute animal parasite of the 

 blood related to the plood parasite of 

 Texas fever. The parasite is found in 

 the blood, liver, spleen, kidneys, and 

 other organs, and the disease appears 

 to be confined to sheep. Among the 

 first symptoms are fever and bloody 

 urine, followed by a yellow condition of 

 the skin and dropsical swellings or- the 

 side of the head and neck, after which 

 the animal remains for much of the 

 time in a crouching position. When ex- 

 amined post-mortem, affected animals 

 show a decided yellow color in the skin 

 and fat tissue- and an enlargement of 

 the kidneys. The disease is quite gen- 

 erally distributed in Europe, but in this 

 country occurs chiefly in limited areas 



in the Eocky Mountain states, partic- 

 ularly in Montana and Idaho. No satis- 

 factory remedies have been devised but 

 in a few instances it has been found 

 that goats are not susceptible to the 

 disease and for this reason sheep raisers 

 have taken to grazing goats on the in- 

 fested areas. 



Sheeppox — This disease, while un- 

 known in the United States, might pos- 

 sibly be introduced and is therefore brief- 

 ly mentioned. It is one of the most im- 

 portant and universally distributed dis- 

 eases of sheep in Europe and it has 

 caused the loss of millions of sheep. It 

 still prevails to a large extent in various 

 parts of Europe. The disease is closely 

 related to cowpox and smallpox. The 

 symptoms include rapid breathing, fever, 

 chills, and depression, followed in a day 

 or two by red spots on the bare parts 

 of the skin. If the eruptions are close 

 together the affected parts become great- 

 ly swollen. After a few days vesicles or 

 pustules are formed which burst and 

 form scabs. A system of vaccination 

 has been devised for the control of sheep- 

 pox. The permanent home of the dis- 

 ease appears to be in Asia, from which 

 outbreaks continually originate. Some 

 of the native sheep of Africa have been 

 found to be relatively unsusceptible to 

 the disease, while European sheep intro- 

 duced into those localities rapidly die 

 by infection. 



Blackleg — (See under Diseases of 

 Cattle.) 



Anthrax — Sheep are very susceptible 

 to this disease and ordinarily develop 

 anthrax in an acute or apoplectic form. 

 (See under Diseases of the Horse.) 



Lockjaw — Tetanus or lockjaw is 

 occasionally observed in sheep as the 

 result of an infection from wounds by 

 nails or splinters. The period of in- 

 cubation is about one week and the 

 death rate is very high. (See under 

 Diseases of the Horse.) 



Tuberculosis — Sheep are not as sus- 

 ceptible to tuberculosis as cattle and 

 hogs, but when an outbreak occurs, af- 

 fected animals should be separated from 

 the rest of the flock in order to prevent 

 the further spread of the disease. 



Ulcerative leg infection — A disease 

 resembling erysipelas appeared among a 

 number of herds of sheep in New York 

 and also affected dairy cows in the same 

 locality. The first symptoms were swell- 

 ing in the region of the fetlock and pas- 



