Pruritis 3 - Ectoparasites Flashcards
What ectoparasites cause pruritus in dogs?
Sarcoptes Demodecosis Cheyletiella Lice Chiggers
T/F: Sarcoptes in very contagious and zoonotic
True
Clinical signs of sarcoptic mange?
Intensely pruritic - positive pedal reflex
Poorly steroid responsive
Lesions - papule, alopecia, erythema, crust, excoriation
Affected - hocks, elbows, pinnae margins, ventral abdomen, and chest
Predilection for sparsely haired areas
Secondary weight loss
How can you diagnose sarcoptic mange?
Response to treatment
Positive pinnae-pedal reflex
Extremely difficult to find mite on scraping —> take at least superficial scraping form different sites
Fecal flotation
—> often mites are found in feces
What is the treatment for sarcoptic mange?
Topical dips
- anti-seborrhetic shampoo
- 2-3% lime sulfur (dilates follicles)
- amitraz
Topical spot-on / systemic
- selectamin
- modixectin (off label)
- ivermectin
- milbemycin
- fipronil
Treat all affected and in-contact dogs
Treat secondary pyoderma
Clean all bedding/kennels
What demodex sp in in dog?
Demodex canis
What demodex sp is in cats?
Demodex cati
What are the two types of demodecosis?
Localized or generalized
What type of demodex is usually in young patients? Where is is usually found on the body?
Localized; face and forelimbs
What type of demodecosis is found in dogs <18months or adult onset? Where on the body is it found?
Generalized; all over the body and on feet
If a dog has a generalized demodecosis you should do what as part of your diagnostic?
Look for underlying disease
Skin scrape - deep, warm and squeeze the skin
Chronic fibrotic areas - biopsy and histopatholgoy
What is the DDX for folliculitis ?
Fungal — dermatophytosis
Bacterial
Demodex
How do you treat localized demodecosis ?
Mild dz usually heals spontaneously over 6-8wks
Use in Amitraz is not recommended — encourages mite resistance
local application of an antiparasitic ear ointment or a benzoyl peroxide can be used
How do you treat a generalized demodecosis ?
Treatment is long term —> intensive and prognosis could be poor
AMITRAZ!
30-50% of dogs <1yr with generalized demodecosis will heal spontaneously
Over 1yr - definitely needs treatment
Mite counts should be recorded - always manage deep pyoderma aggressively
Clinical cure precedes parasitological cure — continue treatment until at least skin scraps are negative for 3consecutive weeks
What procedure do you follow to maximized amitraz treatment efficacy?
Clip long haired dogs
Warm water soak/shower help dilate follicles
Use a benzoyl peroxide shampoo to remove crust and dilate follicles
Sponge on prep and leave on - DO NOT rinse off
Feet may be specifically managed with a Triatix/mineral oil mixed applied twice weekly
Maintenance dipping may be required for life
T/F: ivermectin is labeled for treatment of demodecosis
False
This is extra label used
Be careful “white feet dont treat” - PCR test for MDR-1 gene mutation
What are signs of ivermectin toxicity ?
Weakness, ataxia, and sleepiness
What are alternative treatments to amitraz for demodecosis
Ivermectin (off label)
Doramectin
Interceptor
Advantage multi
What is the name of the walking dandruff mite?
Cheyletiella mite
Clinical signs of Cheyletiella mites?
Walking dandruff
Scaling
Pruritus , positive scratch reflex, papular crust
T/F: cheyletiellosis is zoonotic
True
How do you diagnose cheyletiellosis
Direct visualization - crawling on fur
Acetate tape test
Flea comb
Treatment of cheyletiellosis?
All in-contact animals
Treat environment
Topical
- shampoo —> selenium sulphide, permethrin, lim sulphur
- spot on - selectamin, moxidectin every two weeks
- fipronil
- Amitraz dips
Treatment length - 6week minimum
What nematode can cause a dermatitis, what are the clinical sings, and how could you diagnose?
Ancylostoma spp or uncinaria spp
Clinical signs
- interdigital areas
- pruritic
- erythema, alopecia, thickening
Diagnose by fecal float
