Otobius

Otobius is a small genus of soft ticks (family Argasidae) that are ectoparasites of mammals and birds. Members are generally small, leathery, and feed on blood, often hiding in protected sites on their hosts between feeds. The best-known species is Otobius megnini, commonly called the spinose ear tick.

Otobius megnini typically spends much or all of its life cycle on a single host. Its life cycle includes egg, larva, nymph, and adult stages. Larvae and nymphs frequently attach in the ear canal, while adults are small and can be overlooked. Feeding can cause local irritation, waxy discharge, ear rubbing, and otitis; heavy infestations may contribute to anemia in heavily infested animals. Hosts include a range of livestock species such as cattle, sheep, goats, horses, and dogs, with occasional reports in other mammals and birds.

Geographic distribution of Otobius species is broad but varies by species. Otobius megnini was described from the southwestern United States and has since been reported in multiple regions across North America, Africa, Asia, and Europe, especially in warm, semi-arid climates where livestock movement can introduce them to new areas.

Ecology and veterinary importance: Otobius ticks are primarily of veterinary concern due to ear infestations and associated discomfort. They are not regarded as major vectors of human or animal pathogens in the same way as some ixodid ticks, and evidence for their role in disease transmission is limited and species-dependent.

Diagnosis and control: diagnosis is typically based on clinical signs and the presence of ticks in the ear canal. Control relies on timely treatment of infested animals with approved acaricides or ear drops, cleaning of the ear canal, and management practices to reduce off-host stages and prevent re-infestation.