External Parasites (Ticks & Mites)

Front 1

Ticks & Mites Description

Back 1

Head, thorax & abdomen are all fused

Mouth parts form "false head"

Larva has 6 legs, adult/nymph has 8 legs

Front 2

Ticks Mouth Parts

Back 2

Composed of:

a) hypostome - backward projecting teeth for attachment

b) chelicerate - for cutting tissue & pumping blood

Front 3

Tick Saliva

Back 3

Inhibits blood clotting

Can cause local irritation or systemic toxicity

Front 4

Tick Life Cycle

Back 4

Simple metamorphosis

Larva, nymph & adult each feed on separate host

Life cycle varies 1-3 years

After mating, female attaches to host and engorges then drops off and deposits egg mass into environment

Front 5

3 Most Common Ticks in Manitoba

Back 5

1. Dermacentor varabilis (wood tick, American dog tick)

2. Ixodes scapularis (deer tick)

3. Rhipicephalus sanguineus (brown dog tick)

Front 6

American dog tick Life Cycle

Back 6

Life cycle can be completed in 8 weeks, but generally takes 2 years

Larval and adult stages usually overwinter before feeding

Front 7

Deer tick Life Cycle

Back 7

Takes 3 years

One year for each stage with overwintering between each stage

Female dies after laying eggs

Larva feeds for 3-5 days, nymph for 3-4 days, and adult female for 14 days

Front 8

Deer Tick Size

Back 8

Adults - sesame seed

Nymphs - poppy seed

Front 9

Brown Dog Tick Life Cycle

Back 9

Takes 2-5 months

Can find all life stages on one dog

Front 10

4 Concerns with Ticks

Back 10

1. Infection/inflammation/myiasis in tick wounds

2. blood less if heavily infested

3. Tick paralysis

4. Disease transmission such as lyme disease

Front 11

Lyme Disease is caused by...

Back 11

bacteria Borrelia burgdorferi

Front 12

How is Lyme Disease transferred?

Back 12

Spread by nymph or adult deer tick

Mice and deer can be asymptomatic carriers

Front 13

Who is susceptible to Lyme Disease?

Back 13

Dogs and humans

Also cats, cattle and horses

Front 14

Symptoms of Lyme Disease in Dogs

Back 14

Loss of appetite

Fever

Depressed

Swollen, painful joints and lameness

Front 15

Symptoms of Lyme Disease in Humans

Back 15

Bulls eye rash in 1-2 weeks

Fever

Rash

Headache

Front 16

How is lyme disease transferred in humans?

Back 16

Most often infected by bites of nymphs (small and hard to see)

Can be bitten by adult but usually seen and removed before disease can be transmitted (36-48 hours)

Front 17

What diseases do mites cause?

Back 17

Mange

Dermatitis

Pruritus

Alopecia

Skin thickening

Dandruff, crusts, scabs

Front 18

2 Major Groups of Mites

Back 18

1. Sarcoptiform mites (pretarsi)

2. Non-sarcoptiform mites (lack pretarsi)

Front 19

Sarcoptiform mites description

Back 19

microscopically visible

oval-round shaped

have pretarsi

Front 20

Non-sarcoptiform mites description

Back 20

not all microscopic

variable shapes and sizes

lack pretarsi

Front 21

What are caruncles

Back 21

wine glass like sucker on end of pretarsi

Front 22

Long pedicels always have ______________

Back 22

small caruncles

Front 23

Short pedicels always have _______________

Back 23

large caruncles

Front 24

Long pedicel can be __________ or ____________

Back 24

Segmented

Unsegmented

Front 25

Short pedicels are always _____________

Back 25

Unsegmented

Front 26

2 Families of Sarcoptiform Mites

Back 26

1. Sarcoptidae - burrow or tunnel into epidermis

2. Psoroptidae - live on skin surface

Front 27

Examples of Sarcoptidae

Back 27

Sarcoptes sp.

Notoedres sp.

Knemidocoptes sp.

Front 28

Examples of Psoroptidae

Back 28

Psoroptes sp.

Chorioptes sp.

Otodectes sp.