Fleas

Question 1

Are fleas arachnids?

Answer 1

No, they are insects!

- Class Insecta, order Siphonaptera

Question 2

Flea morphology

Answer 2

Bilaterally flat, chitinized, wingless

• combs on some species
• blood feeders with host preferences (can survive on accidental host)

Question 3

Are eggs and larvae in the host or environment?

Answer 3

Environment

• larvae feed on organic matter
• pupa create a silk cocoon (highly environmentally resistant)

Question 4

Pulicosis

Answer 4

Evidence of fleas or pruritus

- cause hypersensitivity reaction or flea borne disease

Question 5

What is the cat flea?

Answer 5

Ctenocephalides felis

Question 6

What is the dog flea?

Answer 6

Ctenocephalides canis

Question 7

What is the human flea?

Answer 7

Pulex irritans

Question 8

What is the sticktight flea

Answer 8

Echidnophaga gallinacea

Question 9

What is the oriental rat flea

Answer 9

Xenopsylla cheopis

Question 10

Ctenocephalides felis

Answer 10

Most common ectoparasite of dogs and cats in North America

- uncommon in arid areas

Question 11

What stimulates adult C. felis to emerge from pupae?

Answer 11

• mechanical
• CO2
• temperature
• begin feeding immediately –> females lay eggs in a day –> larvae desiccate easily

Question 12

Ctenocephalides canis

Answer 12

Narrow host range, prefer canids

• restricted distribution
• similar morphology to C. felis
• lower vector importance

Question 13

Pulex irritans

Answer 13

Humans, swine, and dogs

• worldwide distribution
• lack combs, have an ocular bristle
• some vector importance

Question 14

Echidnophaga gallinacea

Answer 14

Poultry (and birds)

• distribution in topical areas
• small size, no combs, angled head
• direct disease on bare areas! = ulcers, anemia, secondary infection

Question 15

Xenopsylla cheopis

Answer 15

Rats, humans, dogs, etc

• tropics and subtropics
• lacks combs, has an ocular bristle!
• disease vector!

Question 16

Direct flea diseases

Answer 16

• flea allergy dermatitis

- anemia

Question 17

Indirect flea diseases

Answer 17

• cestodes: Dipylidium caninum
• nematodes: Acanthocheilonema reconditum
• bacteria: Barontella henselae, Yersenia pestis, Rickettsiae
• virus: myxoma virus

Question 18

What disease is characterized by a flea bite hypersensitivity?

Answer 18

Flea allergy dermatitis

• allergic rxns to antigens in flea saliva = general pruritus and alopecia
• dogs: rump, abdomen, inner thights
• cats: head, neck, dorsum

Question 19

What is the flea tapeworm?

Answer 19

Dipylidium caninum

- transmitted by Ctenocephalides felis (IH)

Question 20

Acanthocheilonema reconditum

Answer 20

Nematode, non-pathogenic

• subq tissues of dog
• transmitted by C. felis (IH)

Question 21

Cat scratch disease

Answer 21

Bartonella henselae

• cats are reservoir
• transmission via C. felis feces

Question 22

Plague

Answer 22

Yersinia pestis

- transmitted bia Xenopsylla cheopis (regurgitated during feeding)

Question 23

Rickettsiae

Answer 23

Rickettsia typhi: murine typhus
- humans
- US
Rickettsia felis
- cat flea

Question 24

Myxoma virus

Answer 24

Myxomatosis

• European rabbits show disease
• historical use in population control

Question 25

What is lack of efficacy in flea treatment due to?

Answer 25

Deficiency in the treatment, NOT resistance!