Otobius spp

From Cow
Adult and nymph Otobius spp ticks

Otobius spp (Spinose ear tick) are one of the more common common ear parasite of cattle in North, Central and South America[1].

These parasites predominately attach to the inner ear, prefering dark, moist environments. They have also been found attached to teh underside pof dairy cattle tails[2].

Species of Haemaphysalis ticks which have been reported in cattle include:

  • Otobius megnini[3]

As well as causing 'tick worry' and tick paralysis, these ticks are vectors for Q fever, tularemia, Colorado tick fever and Rocky Mountain spotted fever[4].

Control of this parasite is usually effective with topical acaricides such as ivermectin, doramectin and fipronil[5]. Commercial vaccines are also being tested in cattle and are showing promise.

Commercially available synthetic acaricides are commonly used, but indiscriminate practices in their application have resulted in the rapid evolution of resistance. Although single acaricide treatment can destroy all of the ticks on an animal, they will not prevent reinfestation[6].

The infested pasture must remain free of all livestock for 6 to 9 months or longer, to break the tick life cycle.

References

  1. Merck Vet Manual
  2. Bulman GM & Walker JB (1979) A previously unrecorded feeding site on cattle for the immature stages of the spinose ear tick, Otobius megnini (Dugès, 1844). J S Afr Vet Assoc 50(2):107-108
  3. Nava S et al' (2009) Field and laboratory studies in a Neotropical population of the spinose ear tick, Otobius megnini. Med Vet Entomol 23(1):1-5
  4. Hall MR et al (2002) Diagnosis of epizootic bovine abortion in Nevada and identification of the vector. J Vet Diagn Invest 14(3):205-210
  5. Kiss T et al (2012) Tick prevention at a crossroad: new and renewed solutions. Vet Parasitol 187(3-4):357-66
  6. Nava S & Guglielmone AA (2009) Difficulties to control natural infestation with Otobius megnini (Acari: Argasidae) nymphs in cattle with systemic biocides. Res Vet Sci 87(2):258-259