VT 113: External parasites fleas and mites

what is the general term for parasites that live on the outside of a host’s body?

ectoparasites

to which Phylum do most ectoparasites belong?

arthropoda

what fraction of all known animal species are members of the Phylum Arthropoda?

approximately 3/4

approximately how many known species belong to the Phylum Arthropoda?

1.1 million

which class of arthropoda includes spiders, ticks, mites, and scorpions?

class arachnida

which class of arthropoda includes flies, mosquitoes, lice, and fleas?

class insecta

how do members of the class crustacea typically impact veterinary medicine?

they serve as intermediate hosts for flukes, tapeworms, and roundworms

what is the primary veterinary concern regarding members of the class myriopoda?

they can produce toxic venom

what is metameric?

having a body composed of repeating segments

arthropods possess an exoskeleton characterized by having_____.

articulations

what type of muscle tissue is found in members of the Phylum Arthropoda?

striated muscle

what type of circulatory system is found in arthropods?

open circulatory system

what is the name of the fluid that circulates in an arthropods open circulatory system?

hemolymph

arthropods are dioecious, meaning they have______.

separate male and female sexes

what developmental process do most arthropods undergo to reach adulthood?

metamorphosis

how many legs does an adult flea have?

6

what are the 3 basic body segments of a flea?

head, thorax, and abdomen

identify the 5 common fleas of veterinary and human importance.

Ctenocephalides canis, Ctenocephalides felis, Pulex irritans, Xenopsylla cheopis, and Echidnophaga gallinacea

which species is the most common flea found on domestic pets?

Ctenocephalides felis

which physical feature is used to identify fleas of the genus Ctenocephalides?

pronotal comb

where does the female Ctenocephalides flea typically lay her eggs?

on the host

Ctenocephalides fleas serve as intermediate hosts for which 2 genera of helminths?

Dipylidium and Dipetalonemma

what is the common name for the flea species Echidnophaga gallinacea?

sticktite flea

in which specific areas are sticktite fleas often found on mammals?

eyelids and ear canals

what distinguishes the sticktite flea from Ctenocephalides species regarding physical structure?

the sticktite flea does not have a comb

which flea species is commonly known as the rat flea?

Xenopsylla cheopis

what internal anatomical feature identifies Xenopsylla cheopis?

a vertical rod on the mesothorax

Xenopsylla cheopis is the primary carrier for which plague-causing bacterium?

Yersinia pestis

what is the common name for Pulex irritans?

human flea

which 3 hosts are commonly affected by Pulex irritans?

humans, pigs, and dogs

what is the most common skin condition caused by fleas in dogs and cats?

allergic dermatitis

what type of blood condition can result from heavy flea infestations?

iron deficiency anemia

which zoonotic rickettsial disease is transmitted by fleas?

Murine typhus

what bacterial disease associated with Bartonella henselae can be transmitted via fleas?

cat scratch disease

what do flea larave typically feed on while on the ground?

organic material

where are flea pupae found during the life cycle?

inside cocoons

insecticides used for flea control are often mixed with which two examples of growth regulators?

Methoprene and fenoxycarb

which class of flea control chemicals is noted for being especially toxic to cats?

Organophosphates

what is the brand name for the flea medication imidocloprid?

advantage

what is the physiological mechanism of imidocloprid?

Neurotoxin insecticide

what is the brand name for the flea medication lufenuron?

program

what is the primary function of lufenuron in flea control?

growth regulator

what is the brand name for the flea medication fipronil?

frontline

to which taxonomic order do both mites and ticks belong?

order Acarina

how many legs does an adult mite possess?

8

how many legs are present in the larval stage of a mite?

6

what characteristics the body segments of a mite?

the head, thorax, and abdomen are fused

in terms of host selection, mites are generally described as being very____.

host specific

what determines the differences in life cycles between various mite species?

whether they are burrowing or surface mites

which hosts are typically affected by the Sarcoptes scabei?

dogs, swine, horses, and ruminants

which mite genus is commonly found on birds?

Knemidokoptes

which mite species affects the ear canals of dogs and cats?

Otodectes

which genus of mite the cause of ‘walking dandruff’?

Chyletiella

which genus of mites is considered the primary one with zoonotic potential for humans?

Sarcoptes

why is it difficult to find Sarcoptes mites on skin scrapings?

they have a burrowing nature

what is the primary symptom of a mite infestation?

pruritus

orbatid mites serve as intermediate hosts for which genus of tapeworms?

Anoplecephala

how is Demodex typically transmitted from a mother to her offspring?

through nursing

in which anatomical location do Demodex mites usually cause localized alopecia in dogs?

the face and extremities

what physical evidence is produced by Otodectes mites in the ear canal?

a wax exudate

how much of their life cycle do scabies mites spend on the host?

th entire life cycle

what is the primary mode of transmission for scabies mites?

direct contact

where do Sarcoptes mites live once they have infested the host skin?

in tunnels in the skin

what secondary condition often follows the intense pruritis and scabbing of a Sarcoptes infestation?

secondary bacterial infection

mites of the genus Psoroptes are commonly found on which hosts?

ruminants, horses, and rabbits

the mite genus Netoedres primarily affects which 3 hosts?

cats, rabbits, and rats

which mite genus is specifically associated with ruminants and horses and is not Sarcoptes or Psoroptes?

Chorioptes