Parasitology --> Exam 1 Lecture 6 (Fleas)

Question 1

Discuss the basics of fleas

Answer 1

• Blood suckers
• No wings –> dont fly
• Prefer 75% humidity and 75 degress Farenehit: uncoimmmon in dry areas but ocmmon in summer and the fall
• Have preferred hosts but are not very host specific

Question 2

Discuss the flea lifecycle and the basiucs of each stage

Answer 2

• 4-6 week cycle can be adaptable
• eggs: 50/day/flea laid; fleces (=blood) are depositied with eggs; both usually fall off host into envionrment
• Larvae: hatch and eat flea feces
• Pupa: can stay in this stage for a uyear
• Adult: flea emerges hungry and seeks host –> once on host, usually stays there

Question 3

Discuss the different fleas species for each animal

Answer 3

• Ctenocephalides felis –<> dog and cat flea
• Pulex –> human flea
• Xenopsylla –> rodent flea
• ## Echidnophaga –> sticktight flea

Question 4

Discuss the basics of identification for fleas

Answer 4

• primarily based on the presence or absence of ctenidia (combs)
• Pronotal comb –> the scarf
• Genal comb –> the moustache

Question 5

Discuss the effects on host for fleas

Answer 5

• Disease transmission
• irritation/pruritis
• Hypersensitivity –> flea allergy dermatitis
• Anemia

Question 6

Discuss disease transmission for fleas

Answer 6

Dipylidium caninum –> tapeworm: zoonoytic
- the most common tapeworm of dogs
- dogs and cats get infected by eating the flea

• Plague - Yersinia pestis is transmitted by the PULEX and XENOPSYLLA
• Yersinia pestis is miantained in cycles between wild rodents

Question 7

Discuss flea allergy dermatitis

Answer 7

Fleas: Hypersensitivty reaction –> flea allergy dermatitis
- the most common dermatologic disease of dogs
- Caused by different types of hypersensitivty: Type 1, Type IV
- IgE and IgG develop in response to antigens in flea saliva
- Pruritis and papulocrustous lesions
-

Question 8

Regarding the clinical signs of flea allergy dermatitis on cats and dogs, discuss the lesion dsitribution and the results of hypersensitivity

Answer 8

Lesion distribution:
- Dogs: lower back, tailhead, and caudal and inner thighs
- Cats: Miliary dermatitis on face, neck, and back

Results of hypersensitivty:
- Alopecia: hair loss
- Erythema: skin reddening
- Pruritis: intense intching results in self trauma
- Acanthosis and hyperkeratosis: thickening of skin
- seborrhea: red, scaly skin
- Secondary bacterial infections
- ww

Question 9

Discuss the diagnosis of flea allergy dermatitis and some differential diagnoses

Answer 9

• Clinical signs + evidence of flea infestation + lesion type and distribution (GOLD STANDARD FOR DIAGNOSIS)

Intraderma skin test: immediate reactionm occurs within 15-20 minutes; if negative, check for delayed reaction within 24 hours

Differential diagnoses to rule out (i think):
- atopic dermatitis
- food allergy
- sarcoptic or demodectic mange
- bacterial folliculitis

Question 10

Regarding flwas, what is the main point whenr is comes to the tretament of it

Answer 10

Both the animal and enviornment muist be treated

Question 11

Discuss control and prevention regarding fleas

Answer 11

Control and prevention:
Treat the pet:
- Insect growth regulators (IGRs) –> do not kill insects but prebent them fromn reaching maturity or reproducing
- Adulticides: - Neonicitinoids, isoxazolines, fipronil, pyrethrins, macrocyclic lactones –> these kill adults directly (and somnetimes larvae too)

• The are also often used in combination as a multimodal approach

Question 12

Regarding fleas in terms of control and prevention, discuss the topic of insect growth regulators and adulkticides

Answer 12

Insect growth regulators:
- Lufenuron (monthly oral chews)
– Methoprene (tiopical spot on)
- Pyriroxyfen

Adulticides: Mainly act on the adul;t flea stage, Then for all the best macrocyclic lactones, selamectin is best for targeting the adult stage; adulticides act on ion channel to eventually causes paralysis

• Neonicitinoids –> imacloprid; nitenpyram
• Fipronil (frontline) - topical
• Macrocyclic lactones –> selamectin - topical
• Indoxacarb - topical
• Isoxazolines - monthly chewables
• **Pyrethrins –> TOXIC TO CATS exce[pt flumethrin

Question 13

Regarding the contorl and prvention of fleas, discuss the basics

Answer 13

• Enviornmental control is just as important as drug application
• First line of defense = vacuum
• Envionrmental control = **adulticide (pyurethrin) + insect growth regulator
• **