The female has two pairs of long setae at the posterior margin of the body, while the male has a single pair. P. ovis in sheep is the cause of Australian itch, while P. bos is relatively benign in cattle. The hair follicle mite is worm-like in outline and therefore easily distinguishable from other genera. The four short pairs of legs are situated directly behind the gnathosoma. In cleared preparations, even several mites can be overlooked because they lack contrast.
Adults have four pairs of short legs that have no suckers.
The legs of the female mite are very short, whereas those of the male are much longer. On the dorsal surface just behind the gnathosoma, two parallel sclerotic rod-like structures are present. A less sclerotic transverse area between the caudal ends of these rods results in a U-shaped sclerosis. The dorsal surface striations in K. mutans are interrupted in the mid-region to form rounded scales. The mites resemble K. mutans , but differ from the latter in having a noninterrupted dorsal striation.