External Parasites

Question 1

Define

Symbiosis

Answer 1

Two organisms living together

Question 2

Define

Mutualism

Answer 2

Two organisms living together where both benefit

Question 3

Define

Commensalism

Answer 3

Two organisms living together
* one benefits
* other neither benefits or is harmed

Question 4

Parasitism

Answer 4

Organism lives on or in host and may be pathogenic
* ectoparasite = external
* endoparasite = internal

Question 5

Define

Obligate Parasite

Answer 5

Parasite unable to lead a free-living existence

Question 6

Facultative Parasite

Answer 6

Organisms that are non-parasitic in nature by can become parasitic in certain hosts

Question 7

Reservoir Host

Answer 7

Vertebrae host that has the parasite and is source of infection

Question 8

Definitive Host

Answer 8

Harbors the adult, sexual, and mature stages of parasite

Question 9

Arthropods

Answer 9

• Exoskeleton with segments
• True body cavity
• Circulatory, Excretory, Nervous, Reproductive Systems
• Jointed legs
• Egg reproduction (2 sexes)
• Insects vs Arachnids

Question 10

Insects

Body Anatomy

Answer 10

• 6 Legs
• Head / Thorax / Abdomen
• May or may not have wings
• Antennae
• Mouthparts for chewing/sponging/sucking

Question 11

Insects

Examples

Answer 11

• Fleas
• Lice
• Flies

Question 12

Arachnids

Answer 12

• 8 legs
• Cephalothorax / Abdomen
• No antennae
• Mouthpart for cutting

Question 13

Arachnid

Examples

Answer 13

• Ticks
• Mites

Question 14

Flea Life Cycle

Answer 14

• Eggs on host fall off and into environment
• Eggs hatch into larvae - feed on organic debris (poop)
• Larvae spin cocoons
• Adults emerge based on vibration, pressure, heat, noise, CO2
• Adults always parasitic - can live for extended periods of time in environment

Question 15

Dog and Cat Flea

Technical Name & Info

Answer 15

Ctenocephalides (felis and canis)
* anemia with heavy infestation
* saliva is antigenic - hypersensitivity and dermatitis
* observe near base of tail, ventral abdomen, and chin

Question 16

Fleas as Vectors

Answer 16

• Dipylidium caninum
• Plague
• Rickettsia (typhus)

Question 17

Lice

Technical Name

Answer 17

• Mallophaga
• Anoplura

Question 18

Lice Severity

Answer 18

More severe in:
* young/old/poorly nourished
* overcrowded conditions
* colder months

Question 19

Mallophaga

Answer 19

• Mouthpart = biting/chewing
• Moves rapidly
• Smaller
• Broad, rounded head

Question 20

Anoplura

Answer 20

• Mouthpart = sucking
• Moves slowly
• Larger size
• Long, narrow head

Question 21

Answer 21

Mallophaga Lice

Question 22

Answer 22

Anoplura Lice

Question 23

Mites and Ticks

Technical Name

Answer 23

Acarina

Question 24

Hard Ticks

Technical Name

Answer 24

Ixodidae

Question 25

Brown Dog Tick

Answer 25

* Rhipicephalus sanguineus * Transmits E. canis and Babesia

Question 26

Answer 26

Rhipicephalus sanguineus (brown dog tick)

Question 27

American Dog Tick

Answer 27

* Dermacentor variabilis * Transmits Rocky Mountain Spotted Fever - treat w/ antibiotics * Causes tick paralysis (toxic female saliva) - treat w/ removal

Question 28

Answer 28

Dermacentor variabilis (american dog tick)

Question 29

Blacklegged or Deer Tick

Answer 29

* Ixodes scapularis * Transmits Lyme disease

Question 30

Answer 30

Ixodes scapularis (blacklegged or deer tick)

Question 31

Lone Star Tick

Answer 31

* Amblyomma americanum * Causes Masters Disease - rash illness (presents like lyme in humans) * Can also cause Rocky Mountain Spotted Fever

Question 32

Answer 32

Amblyomma americanum (lone star tick)

Question 33

Sarcoptes Mites

Answer 33

* Burrow/ tunnel into superficial layer of skin * Localized inflammation and hair loss * Prefers areas with little hair - ears, elbows, hocks, ventrum * Spreads rapidly - direct contact * Extreme pruritus * Diagnose with superficial skin scrape

Question 34

Answer 34

Sarcoptes Mite

Question 35

Demodex Mites

Answer 35

* Burrowing mite into hair follicles and sebaceous glands * Immunodeficiency needed for infestation * Causes hair loss, thickening skin, and pustules * Not pruritic unless secondary infection * Not contagious (though transferred to babies from mom in dogs) * Deep skin scrap needed to diagnose

Question 36

Demodex Infestations | Types

Answer 36

Localized * red, scaly lesions on face or forelegs * goes away on own once immunocompetent Generalized * patchy fur and alopecia over entire body * treatment recommended Pododermatitis * confined only to paws - last stronghold * often generalized during recovery * may require biopsy to diagnose

Question 37

Answer 37

Demodex Mite

Question 38

Otodectes Mites

Answer 38

* Ear mites * Live in external ear canal of cats and dogs

Question 39

Answer 39

Otodectes Mite

Question 40

Cheyletiella Mites

Answer 40

* Walking dandruff * Causes dry, scaly dermatitis with dandruff * With or without pruritus * Find on dorsum above tail and neck * Highly contagious

Question 41

Answer 41

Cheyletiella Mite

Question 42

Rocky Mountain Spotted Fever | Vectors and Symptoms

Answer 42

Transmitted by * Dermacentor * Amblyomma americanum Symptoms * fever * chills * headaches * muscle pains * rash

Question 43

Tick Paralysis | Vector and Symptoms

Answer 43

Transmitted by * Dermacentor Symptoms * paralysis progresses back to front * anorexia * lethargy * muscle weakness * ataxia * nystagmus

Question 44

Lyme Disease | Vector and Symptoms

Answer 44

Vector * Ixodes scapularis Symptoms * fever * shifting leg lameness * swelling in joints * lethargy * anorexia