Lecture: flea allergy Flashcards Preview

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Flashcards in Lecture: flea allergy Deck (22)
1

Flea biology

  • Order: siphonoptera
  • Chitin exoskeleton with hairs and spines
  • laterally compressed body
  • three pairs of jointed legs
  • resistent to high pressure and cold temps
  • Males smaller than females
  • can accelerate 50X rate of space shuttle
  • can jump equivalent of a man jumping 1,000 ft

2

Most common flea of dogs and cats

Ctenocephalides felis

3

Human flea

pulex irritans

4

Avian stick tight flea

  • Echidnophagia gallinacea
  • exposure to birds or pouldry farms
  • easily seen on margin of pinnae

5

Ctenocephalides felis

Transmission of disease

  • Can harbor plague
  • murine typhus and tularemia
  • dipylidium caninum
  • cat scratch fever
  • tapeworks (I think)

6

Ctenocephalides felis

biology

  • not host specific
  • adult spends entire life on host
  • life cycle 21 days in fl
  • doesn't survive high altitude or low humidity

7

Ctenocephalides felis

Eggs

  • laid after blood meal
  • fall off host into environment
  • resistent to all insecticides except IgR

8

Ctenocephalides felis

Larvae

  • Present in environment
  • covered with small hairs
  • molt twice
  • move away from light and hot temp
  • rudimentary eyes
  • limited movement
  • eat small organic debris/blood filled flea feces
  • vacuuming helps

9

Flea feces

  • fecal coil
    • long coil = uninterrupted feeding

10

Ctenocephalides felis

Optimum env

  • 65-80 degrees F
  • 65-75% humidity

11

Flea cacoon/pupa

  • most resistant stage
    • resistent to freezing, desiccation, insectisides
    • difficult to remove by vacuuming
  • Larva uses environmental material
  • can be dormant for months

12

Emergency of young fleas from pupa

  • mechanical pressure/vibration
  • body temp
  • low conc CO2
  • young animals seek host and blood

13

Flea allergy

predisposing factors

  • Lack of exposure neonatally or at a young age
  • Intermittent exposure
  • small amounts
  • atopy

14

Flea allergy 

hypersensitivity

  • Type 1
    • IgE mediated
      • mast cells and histamine
  • Type 4
    • delayed sensitivity
    • cell mediated: lymphocytes => T-cells

*mixed pathogenesis can screw up a intradermal test

15

Clinical signs of FAD

  • Primary lesion = papule
  • Pruritis 
    • one of three most pruritic dz in dogs
  • self-trauma and absence of fleas
  • worsens with time
  • signs can be seasonal

16

FAD skin lesions

  • Back half of dog
  • lower back, perineum, tailhead, hind legs and umbilical region
  • racing stripes

17

Common seconary infection to FAD

Staph

18

Feline flea allergy dermatitis

  • Miliary dermatitis
  • Feline symmetrical alpecia
  • Eosinopilic Granuloma complex

19

Manifestations of flea allergies

20

Diagnosis of FAD

  • Clinical signs and rule/outs
  • Presence of fleas or feces
  • carrier animals 
  • tapeworm history
  • positive response to eliminatin of fleas

21

FAD Treatment

  • Kill the fleas
  • treat pyoderma
  • antipruritic therapy

 

  • Steroids for inflammation?
  • Antihistamines?
  • No IT (immunotherapy)

22

Other FAD therapy

  • Chemical adulticides on pets
  • repellents in allergic dogs
  • IGRs (Insect growth regulators)
  • Rotation of products
  • product year round