TREMBLING IN SHEEP. EOUPING-ILL,. INFECTIVE 

 MYELOMENINGITIS. IXODIC TOXAEMIA. 



Definition : infective, tick-borne disease, characterized by meningo-mye- 

 litis. Animals susceptible : sheep, and possibly swine (Meek, Greig-Smith) 

 and cattle (Williams). Known in North Britain only in spring (in Skye 

 also in autumn), on rough pasture with much brush, and wood ticks, 

 (Ixodes ricinus, erinaceous, marginatus or other). Experimental infection. 

 Bacteriology : Bacterium fiuorescens /3 and 7 found in exudate and infect- 

 ing. Accessory causes : dried grass of previous year, brush, low condition, 

 cold, youth. Symptoms : incubation 10 to 30 days ; impaired innervation, 

 hyperesthesia, timidity, excitability, trembling, jerking, lack of coordina- 

 tion and balance, falling, convulsive struggling, jumping, rolling of eyes, 

 stiffness, opisthotonos, paresis, paralysis of hind — later of fore limbs, apathy. 

 Wry neck, arched back, stiff joints. Diagnosis from myelo-me>iingitis by 

 its enzootic appearance, in spring, on tick infested ground : from paralytic 

 rabies, also by absence of that disease locally ; from tetanus by its general 

 prevalence, the absence of tonic spasm, and presence of palsy ; from braxy 

 by the lack of emphysematous swellings, and of speedy sepsis ; from an- 

 thrax by usually healthy spleen and its confinement to sheep. Lesions : 

 cerebral meningitis with encrease of subarachnoid fluid, of myelon, red- 

 dened, s-oftened, also of other serosse, stomach, bowels, liver and kidneys. 

 Prevention : destroy ticks in winter by burning grass and brush, by plough- 

 ing and cropping ; or fence off J4 the pasture one year and the other half 

 next; or lime soil ; or dip repeatedly in April, May and June to keep off 

 ticks ; avoid moving sheep in these months : Give liberal feeding. Mor- 

 tality 10 to 20 per cent. 



Definition. An infective disease of sheep, inoculated by ticks, 

 and producing a meningo-myelitis, with drowsiness, hyper- 

 sesthesia, irritability, paresis and other nervous disorders. 



Animals susceptible. This is almost exclusively a disease of 

 sheep, yet Meek and Greig-Smith claim to have seen it in swine 

 that have eaten the raw carcasses of louping-ill sheep, or that 

 have ranged the tick infested pastures, and in rabbits inoculated 

 with the microbe from the wound caused by the tick. W. Wil- 

 liams claims to have seen well marked cases in cattle, and heard 

 of cases in horses and swine. He speaks, however, rather ob- 

 scurely of " the tick disease^ and seemingly includes in this all 

 affections inoculated by ticks. 



Geographical Distribution. This disease has been hitherto de- 

 scribed as existing in the northern part of Great Britain only, 



500 



