Fleas Flashcards
Are fleas arachnids?
No, they are insects!
- Class Insecta, order Siphonaptera
Flea morphology
Bilaterally flat, chitinized, wingless
- combs on some species
- blood feeders with host preferences (can survive on accidental host)
Are eggs and larvae in the host or environment?
Environment
- larvae feed on organic matter
- pupa create a silk cocoon (highly environmentally resistant)
Pulicosis
Evidence of fleas or pruritus
- cause hypersensitivity reaction or flea borne disease
What is the cat flea?
Ctenocephalides felis
What is the dog flea?
Ctenocephalides canis
What is the human flea?
Pulex irritans
What is the sticktight flea
Echidnophaga gallinacea
What is the oriental rat flea
Xenopsylla cheopis
Ctenocephalides felis
Most common ectoparasite of dogs and cats in North America
- uncommon in arid areas
What stimulates adult C. felis to emerge from pupae?
- mechanical
- CO2
- temperature
- begin feeding immediately –> females lay eggs in a day –> larvae desiccate easily
Ctenocephalides canis
Narrow host range, prefer canids
- restricted distribution
- similar morphology to C. felis
- lower vector importance
Pulex irritans
Humans, swine, and dogs
- worldwide distribution
- lack combs, have an ocular bristle
- some vector importance
Echidnophaga gallinacea
Poultry (and birds)
- distribution in topical areas
- small size, no combs, angled head
- direct disease on bare areas! = ulcers, anemia, secondary infection
Xenopsylla cheopis
Rats, humans, dogs, etc
- tropics and subtropics
- lacks combs, has an ocular bristle!
- disease vector!
Direct flea diseases
- flea allergy dermatitis
- anemia
Indirect flea diseases
- cestodes: Dipylidium caninum
- nematodes: Acanthocheilonema reconditum
- bacteria: Barontella henselae, Yersenia pestis, Rickettsiae
- virus: myxoma virus
What disease is characterized by a flea bite hypersensitivity?
Flea allergy dermatitis
- allergic rxns to antigens in flea saliva = general pruritus and alopecia
- dogs: rump, abdomen, inner thights
- cats: head, neck, dorsum
What is the flea tapeworm?
Dipylidium caninum
- transmitted by Ctenocephalides felis (IH)
Acanthocheilonema reconditum
Nematode, non-pathogenic
- subq tissues of dog
- transmitted by C. felis (IH)
Cat scratch disease
Bartonella henselae
- cats are reservoir
- transmission via C. felis feces
Plague
Yersinia pestis
- transmitted bia Xenopsylla cheopis (regurgitated during feeding)
Rickettsiae
Rickettsia typhi: murine typhus - humans - US Rickettsia felis - cat flea
Myxoma virus
Myxomatosis
- European rabbits show disease
- historical use in population control
What is lack of efficacy in flea treatment due to?
Deficiency in the treatment, NOT resistance!
