Ticks are important to human and veterinary medicine
for a variety of reasons:
- as vectors of bacterial, protozoal, rickaettsial, spirochaetal
and viral diseases of humans, domestic stock and companion animals.
- as ectoparasites with irritating bites causing extensive harm
to their hosts due to blood loss, damage to the skin and anorexia
leading to reduction in growth.
- as agents of 'tick paralysis' in man and animals, probably due
to the secretion of toxic substances in their saliva.
- in exacerbating the lesions caused by Dermatophilosus
congolensis (dermatophilosis) in cattle, goats and sheep; this is
caused by immunosuppressive effects of the tick feeding.
- in predisposing their hosts to other arthropod infestations
such as the screwworm fly, Cochliomyia hominovorax.
appendiculatus, the brown ear tick, feeding on the ear of a calf.
This African tick transmits Theileria parva infections, Anaplasma
centrale and Babesia bigemina which cause East Coast fever,
anaplasmosis and babesiosis respectively in cattle.
Engorged female of Hyalomma sp. feeding on the skin between
the spines of a hedgehog.