97 
Gid , Sturdy , 8fc., in Sheep. 
Here the hermaphrodite tapeworm becomes full of eggs, and 
each segment which passes with the faeces of the dog contains 
incredible numbers. If one of these eggs is taken by the 
sheep with its food or water it passes to his nervous system 
and develops into a bladder. The “gid” of the sheep and 
tapeworm of the dog are therefore dependent on the eating by 
the dog of the brain of the sheep, and on the sheep eating 
(or drinking) what has passed from the dog. 
As a rule there are only a few animals in a flock affected 
with “ gid ” at the same time, but occasionally it happens in 
a much more serious form. Instances have come under the 
notice of the writer in which 75 per cent, of the lambs of a 
large flock have become fatally affected, 300 having succumbed 
within four months. 
Symptoms . — The manifestations of the presence of the 
hydatid in the brain of the sheep are too well known to require 
lengthy reference here. These will vary according to the 
situation and size of the bladder, and may interfere with any 
function of the brain. Most commonly, movements are 
abnormal. The affected sheep may move in a circle, step 
high, or trot ; .indeed, perform any apparently purposeless 
or uncontrollable movement. In some cases loss of power 
(paralysis) is the leading feature. Blindness is not infrequent. 
Loss of flesh is almost invariable, and if the animal is allowed 
to live long after symptoms are first observed, there may 
be bulging and softening of the bones of the brain case. 
Prevention .— Our knowledge of the life-history of this 
worm allows the adoption of precise measures for prevention. 
All dogs, likely to get on to places where sheep are kept, 
should be periodically dosed with worm medicines (as areca 
nut), tied up in a house for a few days, and the droppings 
carefully swept up and burnt. If all dog owners were to 
follow this practice, “ gid ” of sheep would be, indeed, a rare 
disease. The heads of sheep containing the bladder worm 
should be destroyed or, at least, thoroughly boiled before being 
eaten by dogs. The cure may be sometimes effected by surgi- 
cal operation, i.e., by trephining the bones of the skull and 
removing the bladder. This is a somewhat favourite perform- 
ance of mountain shepherds. It is, occasionally, successful, 
and may be interesting to the operator, but the easier method 
of prevention by the means suggested is also more economical 
and worthy of adoption. 
John Penberthy. 
Royal Veterinary College, London, N.W. 
VOL. 67. 
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