136
Common Diseases of Young Calves
animal to another by direct contact and indirectly by posts and other fittings
in the calf pens, against which the infected calves may have rubbed their
bodies or which may be contaminated by clothing or grooming utensils used
on infected calves.
In calves the lesions are commonly found round the eyes, base of the ears
or neck, shoulders, mouth and lips (Plate XIII, fig. 4). The parasite attacks
the skin and destroys the hair which becomes brittle and breaks off, so that the
disease is manifested by circular bare patches of skin which soon get covered
with bran-like scales, but after a time the patches become covered with scabs
of silvery grey colour. Sometimes these scabs crack and bleed, especially
when the animal rubs the lesions against hard objects which it does owing to
the irritation. The lesions do not heal spontaneously but they clean up suffi-
ciently during summer and readily respond to proper treatment.
In order to control an outbreak of this disease the affected animals should
be separated from the non-affected ones, the premises should be kept clean,
dry, properly ventilated and disinfected, and the litter should be removed daily
and burnt. Clothing, grooming utensils, etc. should be disinfected by boiling
or soaking in 10 per cent carbolic solution or 1 in 1000 solution of mercury
perchloride. Disinfection of walls, floors, partitions and other fittings
should also be done carefully. The calves should be brushed, groomed and
kept clean. A liberal diet should be allowed. Cats and dogs should not be
allowed to run about the infected premises as they may disseminate the infec-
tion. The affected calves should be looked after by separate attendants. The
best way of treating the lesions is to remove hair from round about them,
soften the scabs with warm water and soap and remove all the debris, which
should be burnt. Allow the parts to dry and then apply tincture of iodine or
equal parts of tincture of iodine and vaseline or 1 in 40 ointment of biniodide
of mercury. For widespread lesions one part of sulphur, one part of potassium
carbonate, one part of oil of tar with 8 parts of lard or oil is quite good. A
case should be considered as cured only when there is no longer a scabby
condition of the skin and a good smooth crop of new hair grows.
(iv) Tick infestation.—There are a variety of ticks found infesting cattle
in India and Hyalomma aegyptium (Plate XIII, fig. 6) and Boophilus australis
(Plate XIII, fig. 5) are the more common ones. The latter tick transmits bovine
piroplasmosis which is commonly known as red-water in cattle. Since calves
possess a considerable degree of resistance to piroplasmosis it does not appear
in them in its clinical form in spite of their harbouring the infected tick.
They may, however, develop a mild attack and become immune to this disease
for the rest of their lives. The harm, therefore, done by the ticks to calves is
due only to their sucking the blood of the host, which becomes anaemic and
to their inoculating into the host's body a poisonous saliva which creates un-
easiness and emaciation so that the affected young animal develops poorly.
The skin may appear rough and uneven on account of the attachment of
ticks, which are found more numerously on the neck, ears, navel, thighs,
etc. Pustules and ulcers may develop when the ticks have been torn from their
host by licking or rubbing.
The best method of eradicating ticks from a herd is to burn the vegetation
from the pastures, cultivate or change the pastures and house the animals in
pukka buildings where there are no cracks in which the female tick can