Parasitology mites Flashcards
(36 cards)
Phylum and subclass for mites
P- Arthropoda
Sc- Acari
What are the four main stages in the life cycle of mites?
Egg
Larva
Nymph
Adult
Leg numbers
Nymphs, adults 8
Larvae 6
What are the 2 functional groups of important mites?
Typical parasitic mite
Atypical parasitic mite
General info about typical parasitic mites
Share many traits with lice: usually host specific, all stages on host, usually short life cycle, transmitted by direct contact, fomites, suckers on legs
Doesn’t survive well off the host
Causes “mange”
diagnosis by skin scraping
General info about atypical parasitic mites
may visit host intermittently
may have some nonparasitic stages
Definition of mange
skin disease of domestic animals caused by number of genera of mites
No characteristic lesion, other skin diseases could look similar
Definition of scabies
mange, cause may vary
small animals usually mean Sarcoptes
large animals could mean other mites
General info about sarcoptic mites
typical parasite mites
burrowing mites- females lay eggs in tunnels in epidermis
Life cycle takes about 3 weeks
Easily transmitted between animals
Diagnosis for sarcoptic mites
Skin scraping- scrape periphery
May be difficult to find so scrape many spots (itching may make the host look worse than the number of mites)
May find mites or eggs on fecal exam (from grooming)
Sarcoptes scabiei
Separate varieties for most common domestic mammals- most often dogs, also pigs
Don’t seem to cross infest
Not all sarcoptes are the same spp. but called the same with variant by host
Sarcoptes scabiei, var canis Clinical importance
Mites like hairless areas/thin hair- lesions may appear first on face, ears, legs
Intense pruritis
Chronic sarcoptic mange you see
alopecia, thickened, wrinkled skin
secondary bacterial infection
self inflicted trauma
Treatment/control of canine sarcoptes
Treat all animals in household
Macrolides used primarily
Extensive environmental treatment not needed b/c live on host– wash bedding, clean kennel, etc.
Zoonotic potential of canine sarcoptes
Lesions in area of contact but can’t establish on humans
humans have their own Sarcoptes
Sarcoptes in pigs
Economically important- lost production in young pigs
Old sows act as carriers
Eradicable from closed system with macrolides
Sarcoptes in other livestock
Rare in ruminants, horses
Can cause severe disease in camelids
Large animal treatment is macrolides
Knemidocoptes, general
Sarcoptic mange mite of poultry and pet birds worldwide
Called scaly face or scaly leg mite depending on where lesions usually seen
Can be a very serious disease
Treat with macrolides
Knemidocoptes, life cycle/ details more than just general
Most common species seen on nonfeathered portions of body
Mites burrow in, cause crusty, scaly lesions
Lesions have a honeycomb appearance
May cause malformations of beak, claws
Psoroptic mites, general characteristics
Surface dwellers, not burrowers
Oval, not round with longer legs than sarcoptic mites
Short life cycle- minimum 2 weeks
Diagnosis by skin scrape (except ear mites)
Macrolides effective
Psoroptes ovis, general and zoonosis
Ruminants, host specific strains- found worldwide, eradicated from sheep in US, status unsure in cattle
Transmission by direct contact
Handlers can get temporary lesions
Psoroptes ovis, clinical importance
Cause severe pruritis and skin lesions Diagnosis by skin scraping *NOTIFIABLE INFESTATION* Importance diminishing with highly effective macrolides Treat all animals
Psoroptes cuniculi
Primarily otic parasites of rabbits
Occasionally in alpacas, goats; rare in horses
Chorioptes spp.
Ruminants, horses, but host specific Direct contact transmission Predilection sites: cattle- tailhead, under and perineal region small ruminants- leg, lower body horses- legs, esp. feathered horses
