April 2018

Scratch that itch

A 3-year-old spayed female German shepherd from Texas was brought to her local veterinary clinic for excessive ear scratching and head shaking. The veterinarian examined both ears with an otoscope and removed these organisms from the ear canal.

What's your diagnosis?

Answer

In this video you can see several soft ticks trying to escape their container. These soft ticks are in fact Otobius megnini, the spinose ear tick. This tick is found in the ears of horses, cattle, dogs, cats, and occasionally people in the southwestern United States. They are recognizable because they lack a scutum and have those conspicuous spines all over the cuticle. The spines are very sharp and painful to the host, which explains the ear scratching and head shaking. The infestation can last for several weeks, and the ticks will stay in the ear as they molt from larvae to nymphs; the adults are not parasitic and are free-living in the environment.