312 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, IV

The exact extent of correlation existing between the virulency of tick infestation
on the one hand and the climatic condition on the other will be readily understood
by a reference to Fig. 3 read in conjunction with Table II.

                          DISSEMINATION OF TICK INFECTION.

Although, a priori, there is a considerable likelihood of tick infestation occur-
ring as a result of contact with infested animals, under natural conditions there
does not appear to be any appreciable spread of the infection by this method since
the tick once attached to the host does not disengage itself except when such a step
is demanded by any special circumstances. However, male ticks do detach them-
selves and wander about in search of mates on the skin of the host itself.

It is generally conceded that the most common way of picking up the in-
fection is from such wooded tracts as providing grazing for cattle. Ticks in
various stages have been observed to climb up blades of grass and leaves of shrubs,
and to remain attached to them by means of their posterior limbs, the anterior
ones being left free to gain purchase on moving animals. During rainy season,
one may observe his cattle returning home in the evening harbouring innumerable
ticks on the extremities of the body, especially on the muzzle. In Kanara it has
been observed that gurgi (Strobinlanthus perfoliatus) and chirkul (Grewia microcos)
bushes are invariably infected with ticks. Thick shrubs of these plants notably of
the former species occur in abundance in the local forests, and these constitute a
favourite hiding place for wild animals during the day time and also harbour ticks
in great abundance.

The cattle sheds as they are constructed in these localities with their rough
mud walls and kutcha floor, are admirably adapted for the breeding of ticks. In
the course of his investigation the writer found certain sheds literally covered with
these parasites. Fodder and Agricultural materials are as much responsible as
cattle themselves for the spread of the infection.

                                           PATHOGENICITY.

Injurious effects caused by ticks may be due to :—

    1. Bites.

    2. Extraction of blood.

    3. Transmission of protozoon diseases.

    4. Tick Toxæmia.

                                              TICK BITES.

Pustules, ulcers and dermatitis are often met with in tick infested cattle.
These lesions are specially seen on the finer skin of the body such as dewlap,