Important SA parasitic diseases Flashcards
What types of Arachnids cause SA parasitic disease?
a) Demodecosis D
b) Sarcoptic mange (Scabies) D
c) Cheyletiellosis D + C
d) Trombiculiasis D + C + H
What is the most common insect hypersensitivity syndrome?
Flea bite hypersensitivity
a) What is Trombiculiasis caused by?
b) What are the other names for it?
c) What are the CS?
d) What is the TX?
a) Trombicula autumnalis (Larvae)
b) Harvest mites
- strictly seasonal (July - Sept/Oct)
c) asymptomatic to severely pruritic - just see orange larvae in between toes, in Henry’s pocket in the ear pinna
d) Tx (none licensed) - fipronil esp spray directly onto regions affected
a) What types of Cheyletiellosis are there to infect the skin?
b) Why is it a concern for pet owners?
c) What animals is Cheyletiellosis seen in?
d) CS?
e) Tx?
a) Cheyletiella blakei, C yasurgi, C parasitivorax
b) Zoonotic
c) Dogs, cats, rabbits
d) CS:
- Walking dandruff (Scaling)
- Pruritus (mild to severe), primarily DORSAL TRUNK
- CATS: miliary dermatitis
Tx - very difficult (>6 weeks)
Treat in contact animal and also environment
None licensed
D + C - fipronil, selamectin, moxidectin, selenium sulphide shampoo
C+R - Ivermectin
D- amitraz
What is miliary dermatitis in cats?
Allergic disease caused from different allergies - breaks out into bumps and crusts along dorsal back, head and neck with erythema underneath
-Cat scratches and licks a lot - causing self trauma - due to pruritus sometimes very severe
a) What causes demodecosis?
b) Is this disease most common in the cat, dog or horse?
c) How does it manifest in juvenile and adults differently?
d) What is the therapy?
a) Inflammatory parasitic disease from larger than normal numbers of demodectic mites
b) Most common in the dog (D. canis) and uncommon in cat (D. cati) and v rare in horse
c) NOT ITCHY
2 manifestations in Juveniles:
1. Localised - recovers spontaneously
2. Generalised - genetic disposition
1 manifestations in Adults (>2 ages)
localised or generalised - underlying immunosuppression (drugs - glucocorticoids, endocrinopathy, neoplasia)
d) Tx of generalised cases - expect 12 weeks
Monitor by repeat Clinical exams and scrapes/plucks
What drugs do you do not use with demodecosis?
AVOID STERIODS - aggregates the disease
How common is Sarcoptic mange in D, C and H?
Common in dogs, rare in cats and v rare in horses (notifiable)
What species is canine scabies caused by and how does it usually manifest?
Sarcoptes scabiei
Intensely pruritic transmissible infestation - itchy, hair loss and inflammation
a) What are the different mechanisms associated with Ectoparasite hypersensitivity?
b) What antigens can the cause of ectoparasite hypersensitivity?
a)
- IgE- mediated (mast cell activation)
- Delayed cell mediated - TH1 (macrophage activation) and TH2 (lymphocyte/eosinophil activation)
Saliva, cuticle, excreted metabolites + enzymes + toxins, faeces
Flea bite hypersensitivity
a) What are FAD patients allergic to?
b) Does flea infestation cause disease in all animals?
c) DDx tests?
d) Tx?
a) Salivary antigens - causing immediate/delayed intradermal reactions
b) flea infestation unlikely to cause lesions in non-FAD - do not feel as pruritic
c) Presence of fleas/flea dirt
Response to therapy can give ddx
Allergy test - intradermal testing
d) Management, anti-pruritic/antiinflamm medication - glucocorticoids, antihistamines
