Canine/Feline Arachnids Flashcards
Ixodes spp.-Common Name
I. scapularis-Black-legged tick, deer tick
I. pacificus-Western black-legged tick
I. rincinus-European sheep tick, castor bean tick
hedgehog tick, British dog tick, Australian and South African paralysis ticks
Ixodes spp.-Hosts
All mammals and birds and humans
Ixodes spp.-Identification
Adults: small (4 mm unfed, 10 mm fed), dark brown, no festoons, inornate scutum, long palps, anal groove forms an arch anterior to anus
Ixodes spp.-Life Cycle
ELNA→Three host tick
Engorged female falls off host to lay eggs in environment→ egg hatch to larva→larvae “quest” for host→attach to host, feed, and drop off→molt to nymph→on host to feed and then fall off→molts to adult→adult seeks host and feeds
Ixodes spp.-Site of Infection
Skin, especially axilla, inguinal region, face and ears
Ixodes spp.-Pathogenesis and Lesions
Paralysis in animals, local skin reactions, transmits Borrelia burgdorferi (Lyme Disease) and Ehrlichia spp., Tick worry
Ixodes spp.-Diagnosis
Engorged females seen easily
Dermacentor spp.-Common Name
D. variabilis-American dog tick
D. andersoni-Rocky Mountain wood tick
D. albipictus-Winter or elk tick
D. nitens-Tropical horse tick
Dermacentor spp.-Hosts
Larvae and nymphs feed on small rodents.
Adults feed on dogs, large hosts and humans, will also feed on cats
Dermacentor spp.-Identification
Rectangular basis capituli, medium size (unfed 6mm, fed 15mm), short palps, ornate scutum, festoons, pale brown to gray
Dermacentor spp.-Life Cycle
ELNA→Three host tick
Engorged female falls off host to lay eggs in environment→ egg hatch to larva→larvae “quest” for host→attach to host, feed, and drop off→molt to nymph→on host to feed and then fall off→molts to adult→adult seeks host and feeds
Dermacentor spp.-Site of Infection
Skin around head and neck
Dermacentor spp.-Pathogenesis and Lesions
Most common tick in most of North America
Transmits Rocky Mountain Spotted Fever (RMSF), tularemia and Babesia spp.
Tick paralysis
Dermacentor spp.-Diagnosis
Id of tick
Rhipicephalus sanguineus-Common Name
Brown dog tick or kennel tick
Rhipicephalus sanguineus-Hosts
Dogs and humans
Will feed on cats also
Rhipicephalus sanguineus-Identification
Hexagonal basis capituli, yellow-reddish-blackish brown, medium sized (5 mm unfed, 12mm fed), inornate scutum, short palps, festoons
Rhipicephalus sanguineus-Life Cycle
ELNA→Three host tick
*Has adapted extremely well to indoor living
Engorged female falls off host to lay eggs in environment→ egg hatch to larva→larvae “quest” for host→attach to host, feed, and drop off→molt to nymph→on host to feed and then fall off→molts to adult→adult seeks host and feeds
Rhipicephalus sanguineus-Site of Infection
Skin, especially between toes and ears
Larva/Nymph often at back of neck
Rhipicephalus sanguineus-Pathogenesis and Lesions/Clinical Signs
Most common in southern US
Transmits Babesia canis, Ehrlichia canis, RMSF
Rhipicephalus sanguineus-Diagnosis
Id of tick
Treatment and Prevention of all Ticks
Remove ticks manually
Regular application of acaricides
Sarcoptes scabiei-Common Name
Sarcoptic mange mite, Itch mite, Scabies mite
Sarcoptes scabiei-Hosts
All domestic animals and humans (doesn’t reproduce and survive well on humans). Rare in cats
Highly host specific
Sarcoptes scabiei- Identification
Round, 500 um, short legs, suckers on long segmented stalks differ b/w sexes
Sarcoptes scabiei-Life Cycle
ELNA. Burrowing mite
Adult lays eggs in tunnels→ eggs hatch in 3-5d→ larvae crawl on skin surface→ larvae burrow in “molting pockets”→ nymph→ adult PPP = 17-21d.
Sarcoptes scabiei-Site of Infection
Skin
Sarcoptes scabiei-Pathogenesis and Lesions
Erythema, scale and crust formation
Sarcoptes scabiei-Clinical Signs
Starts in relatively hairless areas, lateral elbow and pinna of ear are common starting places
Lesions of follicular papules, areas of erythema, crusts of dried serum and blood and pruritus
Sarcoptes scabiei-Diagnosis
Skin scraping but recovery of mites difficult
Sarcoptes scabiei-Treatment and Prevention
MCLs are effective
Treat all pets in household→ extremely contagious
Demodex canis-Common Name
Demodectic mange mite, follicle mite
Demodex canis-Hosts
Dogs
Demodex canis-Identification
“Cigars with legs”
Demodex canis-Life Cycle
ELNA
Lives entirely in hair follicle/sebaceous glands.
Normal to find in dogs but causing problems when they proliferate too much.
Adults lay eggs→ larvae→ nymphs→ adult PPP = 2-4wk
Transmission from Bitch to pup by direct contact.
Demodex canis-Site of Infection
Hair follicles and sebaceous glands
Demodex canis-Pathogenesis and Lesions
Localized demodicosis associated with alopecia, erythema and no pruritus.
Usually in young animals
Prognosis excellent→ typically resolves on its own
Generalized demodicosis characterized by 5 or more areas of localized disease or entire body region, hair sparse, skin coarse and dry, develops “red mange”. Concomitant staphylococcal pyoderma, pustules, difficult to cure
Demodex canis-Diagnosis
Deep skin scrapings and hair plucks can reveal mites
Cytology
Radiography
Demodex canis-Treatment and Prevention
Amitraz (formamidine)
Antibiotics for secondary bacterial infections
Medicated shampoos
Cheyletiella yasguri-Common Name
“Walking dandruff”
Cheyletiella yasguri-Hosts
Dogs, humans
Cheyletiella yasguri-Life Cycle
ELNA
Mites live on skin, hair and tunnel in epidermis debris
Transmission by direct contact
Cheyletiella yasguri-Site of Infection
Fur and Hair
Cheyletiella yasguri-Pathogenesis and Lesions/Clinical Signs
“Walking dandruff” due to walking mites
Cheyletiella yasguri-Diagnosis
Excessive scurf or dandruff
Adhesive tape or scotch tape swab
Cheyletiella yasguri-Treatment and Prevention
Insecticides
Otodectes cynotis-Common Name
Ear Mite
Otodectes cynotis-Hosts
Mostly cats
Dogs, ferrets
Otodectes cynotis-Identification
500 um, long legs, suckers on short unsegmented stalks differ b/w sexes, copious dark cerumen observed
Otodectes cynotis-Site of Infection
Ears
Otodectes cynotis-Pathogenesis and Lesions
Dry, waxy, parchmentlike material in ears with large number of mites, secondary infections resulting in otitis externa
Otodectes cynotis-Clinical Signs
Frequent head shaking
Otodectes cynotis-Diagnosis
Behavior of animal, exudate in ear canal, mites on slide
Otodectes cynotis-Treatment and Prevention
Several remedies
Otodectes cynotis-Life Cycle
ELNA
Transmission by contact with infected animals
Feeds on epidermal debris and tissue fluid from superficial epidermis
