10b – Fleas+Lice Flashcards
1
Q
Insects characteristics
A
- 6 legged adults!
2
Q
Fleas in Canada
A
- Ctenocephalides felis: cats, dogs, 50 spp (BC)
- Ctenocephalides canis: dogs, wild canids (BC)
- *BC as need a high humidity
- Pulex simulans: wildlife, rarely pets
- Pulex irritans: humans, rarely pets
- Xenopsylla spp: rodents
3
Q
Fleas
A
- Requires >50% of relative humidity
- Will bite people, but PREFER ANIMALS
4
Q
P. irritans
A
- No combs
- *HUMANS
5
Q
C. felis adult flea
A
- laterally flattened
- wingless
- 6 legs
- Combs (prontoal and genal)
- *Flat head
6
Q
C. canis adult flea
A
- Round head
- Genal and pronotal combs
7
Q
Lifecycle of fleas
A
- Adults only ones on host: blood feed
- Eggs in environment -> larvae -> pupae
o Pupae can survive up to 4-5 months (environmentally resistant reservoir) - *takes at least 3 weeks
- HIGH relative humidity and 25-30 degree C
8
Q
Pathogenesis of fleas
A
- Anemia: rare, young animals
- Dermatitis
- Flea-bite hypersensitivity
o Flea-bite allergic dermatitis (FAD)
9
Q
Pathogen transmission: IH for
A
- Dipylidium caninum
- Bartonella henselae (cat scratch fever)
- Rickettsia spp.
- Yersinia pestis: rodent fleas, S. SK
10
Q
Flea-bite allergic dermatitis
A
- Intense pruritus (often can’t find a single flea)
- Mixed type 1 and 4 hypersensitivity
- *treat with suspicion with adulticide
- Lower back
11
Q
Diagnosis of fleas
A
- Direct examination/comb
- Flea dirt (frass)
- Intradermal testing for hypersensitivity
12
Q
Treatment of fleas
A
- Adulticides
- Lifecycle disruptors
o Chitin synthesis inhibitors
o Juvenile-hormone analogs - Environmental (vacuum, sprays)
- Cestocide if Dipylidium caninum present
13
Q
Frass=flea dirt
A
- digested blood
14
Q
Lice
A
- HIGHLY host specific
- NOT zoonotic
15
Q
Chewing lice examples
A
- Trichodectes canis: dogs
- Felicola subrostratus: cats
16
Q
Suckling lice
A
- Linognathus setosus: DOGS
- *none in cats
17
Q
Chewing lice: head morphology
A
- Bigger heads
- Mouth parts=perfectly aligned for host hair
18
Q
Sucking lice: head morphology
A
- Smaller head
19
Q
Life cycle of lice
A
- *everything on host
- Adults: blood, feed (sucking), dander (chewing)
- Eggs: not susceptible to treatment (NITS), 1-2 weeks
- Nymph 2-3 weeks till adults
20
Q
Pathogenesis of (lice)
A
- No effects (carriers)
- Dermatitis: head and back
- Pruritus and hair loss
- Anemia (sucking lice)
21
Q
Pathogen transmission (rare) of lice
A
- Dog chewing louse IH for Dipylidium caninum
22
Q
Diagnosis of lice
A
- Young, stressed pets
- Older animals with concomitant diagnosis or neglect
- Clinical appearance
- Direct observation
- Comb, tape +/- KOH digestion
- Lice or nits
23
Q
What do you treat lice with?
A
- Topical insecticides (shampoo, dips, spot-ons)
o UNSAFE for cats
o May have to re-treat in 1-2 weeks (nits resistant) - Many control products work on lice as a single application
- Systemic treatments work better on sucking vs. chewing
24
Q
Human lice
A
- Sucking lice ONLY
- Head, body and pubic lice
- Rarely found pets
- EYES
- Thick antennae
25
Q
Bot flies of dogs and cats
A
- Cuterebra: rabbit bot fly
26
Q
Cuterebra spp. life cycle
A
- Adults don’t feed=no mouth
o lay eggs around entrance to burrow in spring - L1 enters through natural opening (nose, wound) of passing dog or cat
- Develops from L1 to L3 in subcutaneous tissue of host for 3-7 weeks
- Pupa overwinters in environment (often see them in cats or dogs)
27
Q
Cuterebra sp. Larva (ex. L3)
A
- Will emerge out of breathing hole -> fall off -> pupate
- *don’t squeeze them out=would cause systemic issues
28
Q
Health significance of Cuterbra
A
- Generally little
- Rarely: abscesses in SQ and brain
- Rarely zoonotic (dermal and nasal)
29
Q
Cuterbra diagnosis
A
- Swelling
- Breathing hole
- Larval emergence
- Seasonal timing (late summer, fall)
30
Q
Treatment of cuterbra
A
- EXCISE
o Do NOT crush=anaphylaxis
