Lecture 3

Question 1

Days after tick infestation to clinical signs of babesiosis

Answer 1

• B.bovis - 8-18 - Babesia bigemina

Question 2

Thieleria buffeli

• Hosts
• Vectors
• Epidemiology

Answer 2

• Cattle
• Harmaphysalis longicornis, Haemaphysalis bancroft and Haemaphysalis humerosa
• QLD and NSW

Question 3

Clinical signs with theileriosis

Answer 3

• Similar to those seen in babesiosis or anaplasmosis: fever, LOA, weakness, muscle tremor, jaundice, haemoglobinuria
• 3 death recorded, in all three cases parasitemia approached 100%

Question 4

Diagnosis with theileriosis

Answer 4

• Complicated by the presence of babesiosis and anaplasmosis
• Blood smears: bacillary/bayonet and oval forms are common in chronical infections

Question 5

Where is theileria present

Answer 5

Blood smears

Question 6

What is the lifecycle of Theileria

Answer 6

• Infected tick whole feeding inject sporozoites that are present in their saliva
• Sporozoits invade the leukocytes and develop into schizonts
• Merozoites released from schizonts invade the rbc (can be detected in rbc 10 days PI)
• Destruction of RBC
• TICKS: larvae and nymphs, ingest blood with parasitised rbc-> gametes form in the lumen of the gut -> fuse to form zygote -> kinetes
• After tick moults kinetes will penetrate the cells of the salivary glands, multiply and form the sporozoites
• TRANSSTRADIAL TRASNMISSION

Question 7

What is the epidemiology of theileriosis

Answer 7

• Animals recover from the disease but the parasite may persist -> relapses can occur during times of stress
• Prevelence of the disease is rising in QLD, NSW, Victoria
• Disease is usually seen with
  
  • High producing disease-free cattle moved to infected properties near the coast -> clinical signs develop after 4-6 hours
  • Carrier cattle moved to disease free properties and home-bred cattle affected 2-6 months later
  • Home bred calves aged 8-12 weeks

Question 8

How is theileriosis tansferred

Answer 8

• Ticks
• Biting flies
• Needles

Question 9

What is the pathogenesis of theileriosis

Answer 9

Destruction of rbc -> anaemia

• Mechanical action
• Immune mediated
• Elevated levels of methemoglobin

Question 10

What are the clinical signs of theileriosis

Answer 10

• Anaemia, anorexia, weakness, depression, jaundice, abortion, ataxia, fever, weight loss, drop in milk production
• Mortality: up tp 30%

Question 11

Diagnosis of theileriosis

Answer 11

• Blood smears stained by Giemsa
• PCR for confirmation
• Serology tests

Question 12

Treatment of theileriosis

Answer 12

• No drugs are registered in australia
• Less severe cases: oxytetacycline and Imidocarb
• Supportive therapy, rest and no stress

Question 13

Where is Psorobia ovis found

Answer 13

• Found in sheep through Australia

Question 14

What is the location of Psorobia ovis

Answer 14

• All stages are permanent parasires
• On the surface of the stratum corneum and in the superficial layers
• Highest number of dorsal part of the body

Question 15

WHat is the morphology of Psorobia ovis

Answer 15

• Shape: almost circular
• Legs: short/stout and arranged evenly around the body

Question 16

Lifecycle of Psorobia ovis

Answer 16

• Numbers build up slowly - it might take years to spread through a flock
• Number of parasites lower in summer
• Sheering has negative impact of population of mites

Question 17

Transmission of Psorobia ovis

Answer 17

• Direct contact

Question 18

What are the clinical signs in sheep with Psorobia ovis

Answer 18

• Most fleece damage occurs belowe the elbow
• Sheep bite their fleece -> pull wool on the side of body flant
• Sheep rub/scratch -> fleece has a ragged/tuffed appearance

Question 19

Diagnosis of Psorobia ovis

Answer 19

• Clinical signs and the absence of lice
• Confirmation: skin scrapings

Question 20

Treatment of Psorobia ovis

Answer 20

MLs

Question 21

Answer 21

Psorobia ovis

Question 22

Morphology of Chorioptes bovis

Answer 22

• Gnathosoma is short, rounded in outline
• Most legs are long
• Pretarsi are short, not jointed and the pulvilli are cup/bell-shaped
• A pair of well developed posterior lobes, each lobe has 2 long broad flat setae anf 3 normal setae and a pair of copulatory suckers

Question 23

Lifecycle of Chorioptes bovis

Answer 23

All stages are permant parasites

Question 24

Epidemiology of Chorioptes bovis

Answer 24

• Common in temperate areas
• Common in housed dairy
• Clinical signs are seen/most severe during cold weather

Question 25

Transmission of Chrioptic mange

Answer 25

Direct contact

Question 26

Pathogenesis of Chrioptic mange

Answer 26

* Clinical signs are the result of hypersensitivity * Severity of clinical signs can vary from mild to severe * Lesions are common on the tailm perineum, rump, udder, scrotum, distal hind legs * Lesions usually start at the base/root of the tail and spreaf to perineum, udder, hind legs ect * Erythema, papules, nodules that progress to alopecia, fine greyish scales, oozing, thick crusts * Pruritus is gnerally mild to intense -\> animals rub the tail/perineum against the objects -\> exudation -\> crust * Skin in the affected areas become thick, wrinkled and with cevices and abscesses

Question 27

How to diagnose Chrioptic mange

Answer 27

* Clinical signs, location of clinical signs, season, stabled animals * Microscopic examination of the slin scrapings

Question 28

Treatment of Chrioptic mange

Answer 28

* MLs * Ivermectin and moxidectin * Doramectin * Epinomectin

Question 29

Chrioptic mange in sheep and goats

Answer 29

* Lesions are usually seen on hind legs and feet * Common during cold season * Erythema, papules, crust, alopecia, pruritus * Thickening of the skin of the scrotum -\> testicular atrophy and cessation of spermatogenesis

Question 30

Explain what is seen with Demodex bovis

Answer 30

* Nodule and papules up to 1cm in diameter localised mainly on the neck, shoulders, brisket * Nodules contain a caseous material and many mites -\> damage to hide

Question 31

How to diagnose Demodicosis in cattle

Answer 31

Identification of mites in deep scrapings of the skin with lesions