Flea Allergy (Marsella) Flashcards
(16 cards)
Flea allergy dermatitis (frequency)
Most common external parasite. FAD most common skin disease. Most common reason to see vet (outside of vax)
Fleas in dogs & cats
Ctenocephalides felis most common. Pulex irritans (human flea). Echidnophagia gallinacea (avian stick tight flea).
Ctenocephalides felis can transmit…
- Plague
- Murine typhus
- Tularemia
- Diplydium caninum
- Cat scratch fever
Ctenocephalides felis life cycle length
Life cycle 21 days under ideal circumstances (i.e. FL weather)
- Does not survive in high altitude or low humidity
- Adult spends entire life on host
Flea eggs
- Laid after bloodmeal
- Fall off hose in the environment (carpets)
- Resistant to all insecticides except IgR
Flea larva
- Persist in environment
- Molt twice
- Move away from light & hot temp
- Eat small organic debris and blood filled flea feces
Getting rid of larva
Vacuuming helps remove larval food from environment.
- little hairs on larvae help them cling to carpet, so hard to directly take out
Flea cocoon/pupa
- Most resistant stage (freezing, desiccation, insecticides useless, difficult to vacuum up)
- Can be dormant for months
Emergence of young fleas from pupa
Mechanical pressure/vibration, body temperature, low concentrations of CO2 causes young adults to seek a host animal for blood meal.
Predisposing factors to flea allergy
- Lack of exposure neonatally or at young age
- Intermittent exposure
- Small amounts
- Atopy (tendency to be allergic)
Flea allergy hypersensitivity
Mixed hypersensitivity
- Type I (IgE mediated)
- Delayed (IV, cell mediated)
- Cutaneous basophil hypersensitivity
Clinical signs of FAD
- Papules
- Pruritis
- Self-trauma
- Absence of fleas (or just a few)
- Worsen w/ subsequent years
- Age of onset 1-5yrs
- Lesions on back 1/2 of dog (lower back, perineum, hind legs, umbilical area)
- Secondary Staph infections common
- Seasonal w/ waxing & waning of signs
Feline FAD manifestation types
- Miliary dermatitis
- Feline symmetrical alopecia
- Eosinophilic granuloma complex
FAD diagnosis
- Positive response to elimination of fleas
- Clinical signs and rule out other causes
- Precense of fleas or feces (lack of fleas does NOT rule out)
- Carrier animals
- Tapeworm history
- Intradermal skin test (postive confrims, negative does NOT rule out)
- Histopathology
FAD histopathology
- Non-specific
- Superficial perivascular dermatitis w/ eosinophils
FAD therapy
- Chemical adulticides used on pets (all year long)
- Repellents in allergic dogs
- IGR (Flea spray)
- Steroids and antihistamines may help
