Arthropods cats and dogs Flashcards
Ixodidae
-Hard ticks
-common on small animals
Pathogenesis of all species of tick acariasis
-Anemia
-Dermatitis
-Alopecia
-local bacterial infection of bites
Rare additional Pathogenesis of some species
-Paralysis: salivary toxin of female tick
-Alpha-gal syndrome (red meat allergy)
-Pathogen transmission
Hard Tick ID
- Shape of capitulum
- Sexual dimorphism obvious
-Males: scutum over whole back
-Females: anterior scutum - Ornate scutum?
- Festoons present?
Dermacentor variabilis
American Dog Tick
-may transmit Rocky Mountain Spotted Fever, Tularemia, Ehrlichia canis
-present in SK, MB, East
-low prevalence in western Canada
Dermacentor andersoni
Rocky mountain Wood Tick
-may transmit Rocky Mountain Spotted Fever, Tularemia, Colorado Tick Fever
-dominant in BC, AB
-prevalence very low in Western Canada
Causes Tick paralysis in interior BC
Dermacentor adults
-Ornate scutum white markings
-Festoons present
-Short capitulum
-Spiracles
Life Cycle of Dermacentor variabilis and andersoni
Can take as little as 8wks but can last years
1.Eggs in environment
2. Larvae (6 legs)- will go on small host (rodents, rabbits, etc.)- will feed and drop off and become:
3. Nymphs- will go back on small host (rodents, rabbits, etc)- will feed, drop off and become:
4. Adults- will go onto larger host (dogs, people, ungulates). Produce eggs
Rhipicephalus sanguineus
Brown Dog Tick
Can transmit Rocky Mountain Spotted Fever, Ehrilichia canis, Babesia canis (not in Canada), Heptaozoon canis (not in Canada)
Introduced from warmer regions, kennels, houses
Rhipicephalus sanguineus adult
-Inornate scutum
-Festoons present
-Darth vader helmet capitulum
Rhipicephalus sanguineus life cycle
-Often indoor environments
-from months to years
-same species (dog)
- Adults= 8 legs, 8 days
- Larvae= 6 legs, 4 days
- Nymph= 8 legs, 4 days
Ixodes scapularis (MB, East) & I. pacificus
Eastern and Wester Deer Tick/Black Legged ticks
Transmission of Anaplasma phagocytophilum, Lyme disease, Relapsing Fever, Powassan virus
Ixodes pacificus
-Anal groove anterior to anus
-Genital pore
-inornate scutum
-no festoons
-long paralletl capitulum
**Dogs- BC in fall and winter
Ixodes life cycle
- Eggs in environment
- Larvae (6 legs) on small hosts (mice, rodents, rabbits)
- Nymphs (8 legs) on rodents, songbirds, pets, people in Spring. Molt in summer
- Adults (8 legs) on larger hosts (deer, pets, people) in Fall
Three Tiered tick prevention
- Client Education
-modify behaviour and environment
-tick checks; remove within 12-24 hrs - Tick prevention
-repellents (topical insecticides, collars)
-systemic (oral isoxazolines, topical spot ons
3.Testing and vaccination of Lyme Disease
-test if clinical signs and exposure
-vaccinate if live MB and east!
Lyme Disease in Dogs
-Exposure can be detected using serology at least 6-8 wks after tick bite
-95% will never develop clinical signs
-At 2-5mths post-exposure, may see
>shifting lameness, anorexia, fever, nephritis (most common sign), rare neurological, cardiac, ocular issues
Siphonoptera
-Fleas
-6 legged adults
-require more than 50% relative humidity
Ctenocephalides felis
-cats, dogs, more than 50 spp
-laterally flat
-wingless
-6 legs
-genal combs and pronotal combs
Ctenocephalides canis
-dogs, wild canids
Pulex irritans
-human fleas
-no combs
Life cycle of fleas
- Adults on host- blood feed
2.Lay eggs in environment - Larvae in environment
- Pupae in environment (can live for 4-5 mths; environmentally resistant)
**life cycle takes at least 3 weeks
Flea ideal conditions
25-30 degrees C
80-90% relative humidity
**need very high heat to kill
Pathogenesis of Fleas
-Anemia (rare; young animals)
-Dermatitis
-Flea-bite hypersensitivity *allergic dermatitis)
Flea pathogen transmission
Fleas will act as intermediate host for
-Dipylidium caninum
-Bartonella henselae
-Rickettsia spp
-Yersinia pestis
Flea bite allergic dermatis
-intense pruritus but can’t find a flea
-Mixed type 1 and 4 hypersensitivity
-treat with adulticide
Diagnosis of fleas
-direct exam/comb
-flea dirt
-intradermal testing for hypersensitivity
Treatment of fleas
-Adulticides (imidacloprid, selamectin, isoxazolines)
-Life cycle disrupters (chitin synthesis inhibitors, juvenile hormone analogs)
-clean environment
-cestocide if Dipylidium caninum present
Order Phthiraptera
-Lice
>includes both sucking (Anoplura) and chewing (Mallophaga/Ischnocera) lice
-highly host specific, not zoonotic
Trichodectes canis
Dog chewing lice
Felicola subrostratus
Cat chewing lice
Life cycle of lice
- Adults on host (blood, feed- sucking vs. dander-chewing)
- Eggs on host (nits). Hatch in 1-2 weeks
- Nymphs on host (develop within 2-3 weeks)
Pathogenesis of Pediculosis
-no effects
-dermatitis on head and back
-pruritus and hair loss
-anemia if sucking lice
Pathogen transmission in lice?
Rare!
Dog chewing lice intermediate host for Dipylidium caninum
Diagnosis of lice
-in young and stressed pets
-older animals with concomitant disease or neglect
-clinical appearance
-exam; lice or nits present
-comb, tape +/- KOH digestion
Management of lice
- topical insecticides (pyrethroids, pyrethrins, imidacloprid) as shampoo, dips, spot ons
-unsafe for cats
-may have to retreat 1-2 weeks - Can often use flea and tick control products on lice (selamectin, isoxazolines)
**systemic treatments work better on sucking vs chewing lice
- Address possible carriers, fomites, environment
Human lice
-Anoplura- sucking lice
-head, body, pubic lice
-rarely find on pets
ID:
-dorso ventral flat
-wingless
-6 legs
-thick antennae
-conical head
-EYES
Order Diptera
-flies
Cuterebra spp
Rabbit Bot Flies
Life cycle of Cuterebra spp
- Adult flys lay eggs around entrance to burrow in spring
- Larva (L1) enters through natural opening such as nose or wounds of dog ot cat
- Develpos from L1 to L3 in SQ of host for 3-7 weeks
4.Pupa overwinters in environment
Clinical application of Cuterebra
-rare
-abscesses in SQ or brain
-diagnosis: swelling, breathing hole, larval emergenec, seasonal timing (late summer, fall)
-Treatment: excise, do not crush due to anaphylaxis
-Zoonosis rare= dermal and nasal
