General Characters of Suborder Sarcoptiformes (Astigmata) in Veterinary Parasitology
The suborder Sarcoptiformes (Astigmata) includes numerous small-bodied mites, many of which are free-living, although several species are of veterinary importance. They are characterized by the absence of spiracles, with respiration occurring through the body surface, and by distinctive structures such as dorsal scales, spines, grooves, and hairs. Some species also produce specialized hypopial nymphs that facilitate dispersal and survival under unfavorable environmental conditions.
The legs are frequently grouped into two pairs on either side in the nymphal and adult stages and terminate in suckers or claws.
The mouthparts are usually adapted for chewing, with strong chelicerae.
Some species, under unfavorable environmental conditions, produce nymphs that are adapted to resist adverse conditions. These are called hypopial nymphs or hypopi. They are often provided with specialized ventral attachment structures, such as suckers and conoids, which allow them to adhere to transport hosts and facilitate dispersal to more favorable environments.
Several astigmatid mites are of veterinary importance and are associated with mange, dermatitis, otitis, and other skin conditions in domestic animals and birds. Important examples include:
- Sarcoptes scabiei — causes sarcoptic mange in various mammals.
- Notoedres cati — causes notoedric mange, particularly in cats.
- Psoroptes ovis — causes psoroptic mange, especially in sheep.
- Chorioptes spp. — cause chorioptic mange in livestock and horses.
- Otodectes cynotis — commonly causes otodectic otitis (ear mite infestation) in dogs and cats.
- Trixacarus caviae — causes mange in guinea pigs.
- Knemidocoptes spp. — cause scaly skin and leg lesions in birds.
