Arthropods- cattle and sheep

Question 1

Surface mites

Answer 1

-Chorioptes- commonly seen in N. America

Psoroptes sp- more relevant from clinical perspective

Question 2

Burrowing mites

Answer 2

1. Sarcoptes sp
2. Demodex sp

Question 3

Mite life cycle

Answer 3

1.Adults
2. Eggs
3. Larvae
4. Nymphs

**all on hosts; 10-14 days

Question 4

Chorioptes bovis pretarsus

Answer 4

-Pretarsus: trumpets on short unjointed stalks

Question 5

Psoroptes ovis/bovis/equi pretarsus

Answer 5

-Pretarsus: long segmented

Question 6

Psoroptes sp disease notification

Answer 6

-notifiable disease at lab level in canada
-winter season
-host specific
-more rare, but most pathogenic

Question 7

Psoroptes sp disease

Answer 7

Severe generalized pruritis: papules, pustules, erythema, alopecia, crusting, thickening, hair loss. Can be fatal

Question 8

Chorioptes bovis distribution

Answer 8

-most common in Western Canada

-winter season

Question 9

Psoroptic Mange

Answer 9

-hair loss,
-erythema
-thickening
-exudation
-pruritus

**serious in ruminants
**in sheep, causes crusts on skin resulting in loss of fleece

Question 10

Chorioptes disease

Answer 10

Severe localized pruritus
-tail head, escutcheon, coronary bands
-alopecia, oozing, crusting and sometimes ulcers

Question 11

Sarcoptes

Answer 11

-burrowing mite
>very round, back legs very short and do not protrude away from body
-cattle specific; highly contagious in cattle
-only occasionally seen in Canada
-need to treat whole herd

Question 12

Cattle sarcoptic mange

Answer 12

-hair loss
-severe pruritis
-thickened skin

Question 13

Diagnosis of sarcoptes

Answer 13

Multiple deep skin scrapings

Question 14

Transmission of sarcoptes

Answer 14

-cattle to cattle
-fomites

Question 15

Demodex

Answer 15

-mites common (normal skin flora) but demodetic mange is almost non existent
-not contagious to other cattle, not zoonotic
-disease from demodex occurs in immunological problems

Question 16

Demodex in cattle and goats

Answer 16

-clinical demodicosis usually associated with formation of nodular pustules

Question 17

Treatment for Demodex

Answer 17

Only treat individuals who are affected/diseased
*not individuals that have it but no clinical signs

Question 18

Diagnosis for mange in sheep and cattle

Answer 18

-history, season, clinical appearance (degree and extent of pruritis)

Surface mites: KOH digest of superficial skin scrapings, crusts. Serology for Psoroptes

Burrowing mites: deep skin scrapings

Question 19

Treatment and control of mange in cattle and sheep

Answer 19

-ELDU Macrocyclic lactones in Fall
>pour on/topical for Chorioptes
>Parenteral (systemic) for Psoroptes, Sarcopted, Demodex

-Fomites and chutes need to be steam cleaned by acaricide

Question 20

What animals need to be treated for chorioptes?

Answer 20

Sheep, horses, cattle

Question 21

What animals need to be treated for Psoroptes and sarcoptes?

Answer 21

cattle

Question 22

What animals need to be treated for demodex

Answer 22

cattle

Question 23

Dermacentor variabilis

Answer 23

• 3 host
  -SK and East
  -On cattle May-June
  -Transmits Anaplasma marginale in cattle

Question 24

Dermacentor andersoni

Answer 24

-3 host
-West of SK (mainly BC)
-Adults on cattle in Spring
- Transmits Anaplasma marginale in cattle
-toxin from females associated with tick paralysis

Question 25

Dermacentor albipictus

Answer 25

Winter Tick

-located anywhere you have cervids

-adults, nymphs, and larvae in cattle

-may transmit Anaplasma marginale

Question 26

Dermacentor albipictus life cycle

Answer 26

1. Feb- March: Adults feed and mate
2. March-Apr: Fed and bred female falls to ground
3. June: eggs laid
4. Sept-Oct: larvae climb onto platns and wait for hosts to pass by
5. Sept-Nov :larva to nymph
6. Oct-Feb: nymph to adult

Question 27

Otobius megnini

Answer 27

Spinose Ear Tick

-1 host
-only larvae and nymph parasitic; adults are free living
-Northern BC

-not associated with tick paralysis or pathogen transmission

-no symptoms to excess waxy exudate to severe inflammation

Question 28

Diagnosis of ticks

Answer 28

-Direct observation, clinical appearance, SEASON

-ID genus level and be aware of invasives

-serological screening of cows for Anaplasma

Question 29

Treatment and control of ticks on cattle and sheep

Answer 29

-Generally not managed unless paralysis

-Management: fence cervids out, don’t graze in known tick habitat in Spring (D. andersoni, variabilis) or Fall (D. albipictus)

-on label only topical repellents/insecticides (pour ons, sprays, wipes, powders)

Question 30

Anaplasmosis

Answer 30

-bacterial species
-infect cattle and bison, ticks, deer and elk
-Vectors: ticks, biting flies, fomites

Question 31

Clinical signs of anaplasmosis

Answer 31

-none
-weight loss
-hemolysis
-jaundice
-splenomegaly
-abortion
-lethargy
-death (adult cows)
>mortality rate >30%

Question 32

Diagnosis of anaplasmosis

Answer 32

-location, season, signalment, clinical signs, necropsy

-blood smears

-ELISA serology

**Immediately notifiable CFIA disease; also immediately reportability provincially in West

Question 33

Management of anaplasmosis

Answer 33

-Tick and fly biting prevention

-no approved vaccine or treatments
>live and killed vaccines tried ; prevent clinical disease but not infection. Complicated by multiple strains/genotypes

-no antimicrobials will clear carrier animals but they might reduce disease (Chlortetracycline and Oxytetracycline)

Question 34

Haemaphysalis longicornis

Answer 34

-invasive tick
-Asian long-horned tick
-see USA East

Question 35

Amblyomma Americanum

Answer 35

-Lone Star Tick
-Invasive tick
-USA East