Skip to main content

Full text of "Information for farmers and ranchers regarding tick paralysis in British Columbia [microform]"

See other formats








E. A. BRUCE, V.S. 

Animal Pathologist, 

Agass^, B.C. 




In British Columbia about a dozen different kinds of ticks are found. The female 
of one of these ticks (D fas) may under certain conditions cause 

alysis, sometimes followed by death in man and animals. Those chiefly affected are 
children and sheep. 

The Tick. 

In the first plac< drawn to the fact that the six-legged parasites coni- 

:ily found on sheep and whi usually called ticks are not ticks at all but are 

in reality wingless i! ophagus ovinus). It would perhaps avoid confusion it' 

rally called by another common name, thai While the 

sheep ked has on: - the tick when fully grown has eight. 

The paralysis tick (/' irtain parts of Montana is itself affected by 

es which it passes on to man, causing the blown as Rocky Mountain 

Fever or Spotted Fever. Although we fortunately have no records of these ticks carry- 
Spotted Fever in British Columbia, we have a number of records of them causing 
paralysis in man and an in 

Paralysis is caused by the female tick when she is feeding fast, if she is sucking 
blood slowly paralysis does not occur. The explanation for this is not properly knowu, 
but ii is assumed thai when Bhe ; amount of the substance she 

to keep the blood fluid, is injected intp the body in a comparatively short til 
The same substance is undoubtedly secreted when she is feeding slowly, but it is not 
injected into the body in a sufficient amount at one I I rouble. 

A single tick may cause paralysis or even d< 

Distribution. f>. < nustus is found over the greater part of south-eastern British 
Cbluinbia and in the adjacent portion of southern Alberta. It is known to occur 100 
miles north of Kamloops. It sh Columbia, 

but is not plentiful a> wel wei detrimental to its earty stages which are passed 

on small animals (see under lif e-history ) . 

Life-history of the Paralysis Tick (D. venustus). 

This tick ap; an adult early in the spring and at- 

large wild and domesticated animals and on man. T3 mate when on the animal; 

the female after feeding tor aboul days (sometimes more <>r less), and having 

d five or six hunch in weight, drops oiT on to the ground and lays about 

4,000 egg-. After about thirty-six days tin* eggs hatch into minute six-legged larval 
or "seed" ticks. 

The small larval ticks erawl up OB fcher supports, and when the oppor- 

tunity offers get on to small animals such as rabbits, squirrels, ehipniunks, ground 
sguirrels, field mice or other rodent-. They remain on such an animal for about four 
days, drop off to the ground, niouh, and after about thirty-eight day- emerges a- an 
eight-legged middle-si/.ed tick or nymph, which is sexually immature. 

The middde-sized tick or nymph attaches itself to the -ante kinds of small animals 
that the larval ticks £eed on. After about seven days they drop to the ground, moult, 
and in about ninety di S adult ticks. 

Bo1 or cold weather Influences the length of each stage; also, the length of time 
that the larval or nymph ticks have to wait for a suitable host may prolong the whole 


Longevity. Unfed Larval ticks usually die in thirty day-, hut they may live for 

117 days; unfed nymphs may live for '■ $aptured in the spring on ve 




tation have been known to survive for 413 days without feeding, and after fasting for 
365 days readily attach themselves to a host. The life-cycle may be completed in sixty- 
eight days under most favourable circumstances, but usually two yeara is required and 
sometimes thl 

Effects of Tick Bites on Animals. 

possible that other species of animals may be paralysed by D. venustus 

at present we only have definite req»ds for dogs and sheep. The symptoms are prac- 
tically similar in both animals; our remarks will therefore be confined to si 

1 he disease is seen in the early spring, and usually in dry warm locations. The 
first noticeable symptom is restlessness, followed by a staggering . animal n 

bump into obstacles and fall down when trying I hem, a little later it falls down 

; ,nd can no fonger nse but strugg]es a great cloill A> paralysis advances the animal 
ceases to struggle Some of these animals die, but others recover owing to the fact that 
the tick when ti.lly gorged with blood falls off. Animals thai atly 

develop an immunity, ths k,. the disease again or only in a 

mild form. 

f r ' W1 " n] y :i few animals are affected the 1 be picked off by 

hand. Attention should be concentrated on the large female- as the males and unfed 
females are not causing the paralyais. Particular n sbpuld be given to the 

■ 1, neck, and along the back bom majority of those on the will be found 

withm a couple ol i, iie back bone, the region jual above the hocks and k, 

sbpuld also be examined. If the animal do. . ,. v by atrugglin* 

in an hour or two, examine it again. In b oV ery may take some 

days, it a large number of animals at ,| they should be dipped, if the weather 

win permit. The best dip for ticks is one which contain . Probably the sa I 

method for any one not used to handling poisons is , , „f the propr 

. . pa contai nmg arsenic, such as Cooper's Dipping Powder, which can be readily bought 
and which >hould he us ding to then 

Ticks on Cattle and Horses. 

_ Cattle and horses may carry the l>. v, nustus tick, but the c monest tick ton tl , 

animals especially horses, is the "moose tick", Vemvcentor alUpictus. £ dd 
slightly larger than the paralyais tick, and is a little lighter in colour. To complete 
life-cycle it only requires one host and not three as is needed with D. venustus The 
changes from larva to nymph, and fipm nymph to adult take place on „', imai , 

the fertilised ^engorged female drops off i„ fte -man, to lay fro„ 
from which Oielarv* emerge during the summer, but which do no, ,,-nallv attach S 
res to their host until the autumn. ' U "'" 

Thia tick is of -o,ne economic importance as it u, mmcient numb 

*^«»"* ?">ugh Joss of blood. S tim, 

' lo na„ „ Valley who forwarded some specimena of D. Mipictm off hi horaea w . 
I have lost about twenty bead to date (March 26) through these pe*£; a I h'o V ,'. 
■;k". hora ,, e so weak they couldn'1 gel on tl ,,„.,. Eg. 

will l 7 '"'!"!ii" / ' « ;A , n - awenical , di P su <* « Cooper's Powder as recommended for sheen 
Y 11 'I" '"i";> n > fective o„ cattle and horses. Greasy preparations will kill ti-ks ,„•',. , 

blocking their breatlung pores which are 1 ted near their fourth pair of I The 

following may be used: Kerpsene, 10 ounces; lard, nces; pine ,r - uS- , 

plH,, ;V '«t; Jinaeed oil, J pint; sulphur founct ' 

i ■. that pease will kill ticks is well exemplified in examininjr the l„.-,w 

rSflLl'iW U «* be - *- ' ■*- of ticks are Lit £SS 

Effect of Tick Bite on Man. 

A number of eases of paralysis due to ticks have been seen by medical men lb 
interior of the province. The majority of cases occurred in children, but it has been 
seen in a youth of eighteen and twice in adult men. 

The symptoms vary slightly in individual eases, bu1 can be stated to be generally 
I \, - : The patient perfectly well one day, may on the next complain of a numbness 
in the feet and legs and have difficulty in walking; a little later it may be impossible 
to stand up. The hands and arm- tfteu there is a partial 

par;, the throat muscles, there being difficulty in swallowing. The tongue is 

affected, the.- difficulty in speaking properly; it may be impossible to protru 

the ruding it may b ible to withdraw it. 

ostitutiona] symptoms arc slight; there may be some pi sa in the earlj 

or the patient may complain of feeling a bit -^-iW. pain, and usually no 

fever, but the pul iter. 

a certain part- of the legs and arm had lost all b< eeling, am 

slight r; een On the oBest and upper arm. B< are unusual. 

With the exception pf the two cases just mentioned lid that parat 

is confined to tin and does ct the special 

The time from the beginning of symptoms to complete paralysis and even d< 

may be less than tw< at ifl usually from tin The eh: : 

i if the i respiration ot the heart are not affected, 

Tn Medical aid should 1 ■ 

one or n lecially around the nape of the neck, in the hair, and on I 

back and <•!;■ female tick will by this time be bluish in colour and about the 

size of a large bean, and should be f'umd with comparative ease. In rempvifcg a tick 

•/ken nnt to le; head in the skin, otherwise it is lial 

intense irritation, with the probable for ard 

to I tay be made to ir hold by covering them with keros« ine, 

oil of turpentine, or carbolized vaseline; touching with the hot end of a ci prill 

. should be removed with a gentle pull, and if n the 

small ontaining the head can be snip' jsotb. 


itrollrd i stock with an arsenical dip which 

kills the ticks b ud (2) by destroying the small mammals 

upon which the young /■•'. "■< tic&s feed, by the use ilier 


The following formula will be found i mind squirrels (gophei 

Dissolve om aful of saccharine and one ounce of bicarbonate of soda in Ed 

qua; . add half a pound of g] h and heat the mixture until ii 

but do not cook, stirring all the time. To this Bolution ad< of powdered 

Strychnine and mix it well. Tour this mixture- over twelve quarts of whole oats or eight 
quarts of crushed oats, and mix it so that the grain Is thoroughly covered with a 

mous ruatimr. 

About nfui of this grain should be placed in each gopher hole, and for 

preference on clean hard ground, 


l. MaU- h. enlarged. 

pproxinjatelj actual size. 
Fig, 2. I enlarged (unengorged). 

. approximately actual siw (unengorg. 

pproximately actual size (gorged) ; some are 

slightly larger than the one shown.