Skin Parasites

Question 0

What kinds of diseases can fleas spread?

Answer 0

Diphyllidium, bubonic plague, mxymatosis

Question 1

What is the Scientific name for fleas?

Answer 1

Siphonaptera

Question 2

What are the 4 most important flea species? Which is most common in cats and dogs?

Answer 2

Ctenocephalides Felis (cat flea) and C. Canis, Pulex irritans (human flea), ceratophyllus gallinae (poultry flea). Cat flea most common.

Question 3

How is identification of flea species aided?

Answer 3

Ventral (Genal) and Posterior (Pronotal) combs on the head.

Question 4

What are the 4 main stages in flea life cycle? What is important about eggs?

Answer 4

Adult, Egg, Larva, Pupa. Egg is not sticky, so it falls off. 95% of flea population not on the animal.

Question 5

How long is a flea lifecycle?

Answer 5

3-4 weeks.

Question 6

What is Juvenile Hormone?

Answer 6

A hormone required for development of parasites (skin).

Question 7

What is the scientific name for lice?

Answer 7

Phthiraptera

Question 8

What disease do lice cause?

Answer 8

Pediculosis

Question 9

What are the morphological differences between chewing lice and sucking lice?

Answer 9

Chewing lice have a broad head and thinner claws. Sucking lice have a narrow head and large, powerful legs.

Question 10

What are the stages in a louse life cycle? How long does it usually take?

Answer 10

Adult, egg ‘nit’, Nymph. Usually takes 2-3 weeks.

Question 11

How many species of chewing/sucking lice do cattle have?

Answer 11

1 chewing, several sucking.

Question 12

How many species of chewing/sucking lice do sheep have?

Answer 12

1 chewing, 2 sucking. Rare until recently (due to less dipping)

Question 13

How many species of chewing/sucking lice do pigs have?

Answer 13

1 sucking louse. Large and easily seen. Common.

Question 14

How many species of chewing/sucking lice do horses have?

Answer 14

1 chewing, 1 sucking louse.

Question 15

How many species of chewing/sucking lice do dogs have?

Answer 15

Usually chewing louse Trichodectes or sucking louse Lingognathus

Question 16

How many species of chewing/sucking lice do cats have?

Answer 16

1 chewing louse of important, Felicola.

Question 17

How many species of chewing/sucking lice do poultry have?

Answer 17

Many species of chewing louse, no sucking lice.

Question 18

Are ticks insects?

Answer 18

No, they are Acarina. They are temporary parasites (spent small amount of time on host).

Question 19

What is special about tick feeding?

Answer 19

They feed continuously. Saliva contains histamine blocking agents, anti-coagulants etc.

Question 20

What are the stages in a tick life cycle? What is special about ‘seed ticks’?

Answer 20

Adult (4 pairs of legs), egg, larve ‘seed tick’ (3 pairs of legs), Nymph (4 pairs of legs).

Question 21

How can ticks be divided?

Answer 21

Hard ticks and soft ticks.

Question 22

What are the 3 main parts of the tick mouthparts?

Answer 22

Chelicarae (Puncture skin), Hypostome (pushed through hole and anchor), Palp (sensory organs)

Question 23

How do you recognise a hard tick?

Answer 23

It has a hard Scutum, and prominent mouth parts. Scutum covers all of male, part of dorsal surface of female. May have festoons.

Question 24

How is the life cycle of hard ticks categorised?

Answer 24

1, 2, or 3 host ticks depending on the number of hosts they attack to during their lifecycle.

Question 25

How would you recognise a soft tick?

Answer 25

No Scutum, mouthparts not visible dorsally.

Question 26

What are the 5 main ticks of importance in the UK?

Answer 26

Ixodes ricinus, Ixodes canisuga (dog tick), Ixodes hexagonus (hedgehog tick), Haemophysalis sp (mainly cattle - Babesia major), Dermacentor sp (sheep in Wales)

Question 27

What is the more common name of Ixodes ricinus?

Answer 27

Castor bean tick

Question 28

What diseases are spread by Ixodes ricinus?

Answer 28

Lyme disease (human), Louping Ill, tick borne fever, tick pyaemia, red water fever (Babesia divergens)

Question 29

What is important about the Ixodes ricinus lifecycle?

Answer 29

Three tick host, lifecycle is 3 years. Spends most of time on the ground.

Question 30

What condition do mites cause?

Answer 30

Mange.

Question 31

How can mites be categorised?

Answer 31

Burrowing (sub-surface) or Non-burrowing

Question 32

Where do mites spend most of their lifecycle?

Answer 32

On the host

Question 33

Name the three main burrowing mites

Answer 33

Sarcoptes, Knemidocoptes, Demodex

Question 34

Name the 3 main burrowing mites

Answer 34

Psoroptes, Chorioptes and Otodectes

Question 35

What is the important Sarcoptes species? How would you recognise it?

Answer 35

Sarcoptes scabiei. Small round mite, it has short legs and dorsal spines.

Question 36

What is the lifecycle of Sarcoptes?

Answer 36

Female lays egg in egg laying pocket in epidermis. Egg hatch in under a week. Larvae make moulting pocket and become adults. All under a scab.

Question 37

What important disease do Sarcoptes mites cause?

Answer 37

Sarcoptic mange.

Question 38

How can you diagnose Sarcoptes?

Answer 38

Deep skin scrape, place on microscope. 10% KOH and warm. Look for adults and immature mites.

Question 39

What is the treatment used for Sarcoptes mites?

Answer 39

Acaricides e.g. Ivermectin in farm animals.

Question 40

What is important about the host of Knemidocoptes?

Answer 40

Only burrowing mite that occurs in birds.

Question 41

How would you recognise Knemidocoptes mites?

Answer 41

Similar to Sarcoptes (round, short legs), but has a U shaped chitinous bar behind its head.

Question 42

What 3 conditions are caused by Knemidocoptes mites in Poultry?

Answer 42

Scaly leg (K. Mutans), depluming itch (K. Gallinae), Scaly beak (K. Pilae)

Question 43

Why is Demodex different to other burrowing mites?

Answer 43

Usually commensal in hair follicles and sebaceous glands.

Question 44

How do you recognise Demodex mites?

Answer 44

Cigar shaped, 4 pairs of stumpy legs.

Question 45

What two kinds of infection can Demodex cause?

Answer 45

Squamous demodecosis (less serious), pustular or follicular demodecosis

Question 46

How do you diagnose Demodex? How do you distinguish between commensal and disease producing?

Answer 46

Liquid paraffin to skin, take deep skin scraping. High proportion of larvae and nymphs indicate active infection.

Question 47

What is Psoroptes? What are the 3 most important species?

Answer 47

Non-burrowing mites. Ps. Ovis (sheep, cattle), Ps. Equi (horses), Ps. Cuniculi (rabbits, horses)

Question 48

How would you recognise Psoroptes mites?

Answer 48

Long legs, oval shape, segmented Pedicels.

Question 49

What is the main morphological differences for telling the difference between burrowing and non-burrowing mites?

Answer 49

Burrowing usually have short legs. Non-burrowing usually have long legs.

Question 50

How would you tell the difference between Psoroptes and Chorioptes mites?

Answer 50

Psoroptes have segmented pedicels, Chorioptes have unsegmented pedicels.

Question 51

What is the main disease caused by Psoroptes mites?

Answer 51

'Sheep scab' - primarily in late autumn or winter. Active in keratin layer

Question 52

What are the hosts of Chorioptes?

Answer 52

Ruminants and horses

Question 53

How do you recognise Chorioptes mites?

Answer 53

Long legs, oval shape, unsegmented pedicels.

Question 54

Which is more pathogenically significant, Psoroptes or Chorioptes ?

Answer 54

Psoroptes

Question 55

What is Otodectes? What important species is there?

Answer 55

Non-burrowing mite of cats and dogs. It inhabits the external ear. One species: O. Cynotis

Question 56

How do you diagnose Otodectes?

Answer 56

Surface mite and location. (Closed chitinous bars on underside confirm ID)

Question 57

What are Cheyletiella?

Answer 57

Non burrowing mites that infect cats , dogs, rabbits and humans. They cause scaly dermatitis (excessive scurf 'walking dandruff')

Question 58

How would you recognise Cheytiella mites?

Answer 58

Long legs, waisted body, claw like palpable, combs on each leg.

Question 59

What is Dermanyssus gallinae? What is important about its life cycle?

Answer 59

Non-burrowing mite of poultry. Spends most of time off host, feeds at night, eggs laid in housing. It sucks blood.

Question 60

How would you recognise Dermanyssus gallinae?

Answer 60

Spider like long legs, becomes red.

Question 61

What is Neotrombicula autumnalis?

Answer 61

Non-burrowing mite also known as Harvest mite. Paradises anything including humans.

Question 62

Which stage in the lifecycle of N. autumnalis is parasitic?

Answer 62

Larva

Question 63

How do you recognise N. autumnalis?

Answer 63

Surface mite, SIX legs, bright orange, hairy.

Question 64

What are the main mites species infecting cattle? (5)

Answer 64

Sarcoptes, Demodex, Psoroptes, Chorioptes and Neotrombicula

Question 65

What are the main mites species infecting sheep? (5)

Answer 65

Sarcoptes, Demodex, Psoroptes, Chorioptes and Neotrombicula

Question 66

What are the main mites species infecting horses? (5)

Answer 66

Sarcoptes, Demodex, Psoroptes, Chorioptes and Neotrombicula

Question 67

What are the main mites species infecting pigs? (3)

Answer 67

Sarcoptes, Demodex and Neotrombicula

Question 68

What are the main mites species infecting dogs and cats? (5)

Answer 68

Sarcoptes, Demodex, Otodectes, Cheytiella and Neotrombicula

Question 69

What are the main mites species infecting birds?

Answer 69

Knemidocoptes, Dermanyssus and Neotrombicula