Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y3 Infectious diseases > Abortion in sheep > Flashcards

Abortion in sheep Flashcards

1
Q

Give examples of factors that contribute to lambing/rearing percentage

A
  • Fertility (get the ewes pregnant)
  • Lamb survival prepartum (abortion)
  • Lamb survival-intra partum (dystocia)
  • Lamb survival (post partum- neonatal and growing lambs)
  • Sheep: infectious disease and parasitic diseases, veterinary involvement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How long is the gestation of a ewe?

A

147 days (140-150)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 4 main pathogenic causes of abortion in sheep?

A
  • Chlamydia abortus
  • Toxoplasma gondii
  • Campylobacter spp
  • Listeria monocytogenes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What action should be taken on a ewe that aborts?

A
  • Isolate ewe (until discharges have ceased)
  • Remove contaminated material (dead lambs, placenta) and bedding
  • Clean and disinfect area
  • Take Appropriate Samples: Foetus, placenta, blood sample
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the main features of Chlamydia abortus?

A
  • Gram -ve cocci
  • Zoonotic
  • major cause of abortion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the sources of infection for chlamydia abortus?

A

Aborting ewes - main source (Discharges and products of abortion are heavily contaminated, viable for several weeks in the environment)
Carrier ewes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the ROI for chlamydia abortus?

A

Oral route

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the outcomes of exposure to chlamydia abortus to a pregnant ewe?

A
  • If ewe more than 90 days pregnant she may abort

- If less than 90 days pregnant: may abort later or she may become latently infected and abort in the next pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the outcomes of exposure to chlamydia abortus to a non-pregnant ewe?

A

Latently infected harbouring infection in reproductive tract and abort at the following lambing season

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the gross pathology of a Chlamydia abortus infection

A
  • Severe placentitis is with thickening and necrosis
  • Placentitis = inflammation of placenta affects transport nutrients and hormone production – death or damage to lamb
  • Inflammation of a lamb’s internal organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the clinical signs of a Chlamydia abortus infection?

A
  • Abortion after 90 days of pregnancy , often in last month
  • Death of lambs or birth of weak lambs or birth of one live and one dead
  • Ewes vaginal discharge couple days
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is Chlamydia abortus diagnosed?

A
  • Abortion in late pregnancy
  • Gross pathology is a necrotic placentitis
  • Ziehl Nielsen stain
  • PCR
  • Bacterial culture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is Chlamydia abortus controlled during an outbreak?

A
  • Isolate aborted ewes
  • Abortion material (submitted for PM ) or disposed of carefully with bedding
  • Clean and disinfect pens
  • Long acting oxytetracycline to the aborting ewe
  • Treat the flock with a killed inactivated vaccine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is Chlamydia abortus controlled the year following an outbreak?

A
  • Vaccinate all ewes pre-tupping
  • If consider there is risk of ewes being latently infected from previous year, repeat the oxytetracycline injections to exposed ewes the year following an outbreak (not acceptable after that should be using vaccinations after this)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How can Chlamydia abortus infection be prevented?

A
  • Buy a clean flock
  • Buy EAE accredited sheep SRUC health scheme which are tested free
  • Breed your own ewe replacements
  • Or vaccinate the flock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Toxoplasma gondii?

A

A protozoan parasite that infects most species of warm-blooded animals, including humans, and causes the disease toxoplasmosis.
- ZOONOTIC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the role of Cats in Toxoplasma gondii infections/life cycle?

A
  • Definitive host
  • Reservoir for cats is wild life
  • Cats shed millions of oocysts in faeces (then become immune)
  • Oocysts contaminated the environment.
  • Oocyts are very resistant (>500days)
  • Oocyst contaminated sheep feed, pasture, bedding or water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How do sheep become infected with Toxoplasma gondii?

A

Oocysts ingested by sheep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does Toxoplasma gondii affect pregnant and non-pregnant sheep?

A
  • Sheep is not pregnant few clinical signs and become immune

- Pregnant sheep may abort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are Toxoplasma gondii infection outcomes in a sheep at the different points of pregnancy?

A
  • Early pregnancy: foetal resorption will occur and ewes will present as barren ewes. Thus it is an important cause of low scanning percentage
  • Mid pregnancy: foetal death or mummification
  • Later pregnancy: abortion of freshly dead lambs, or birth of live weakly lambs with a high mortality rate, or birth of live and immune lambs
21
Q

How is Toxoplasma gondii diagnosed?

A
  • Gross placenta pathology
  • Histo-pathology foetus and placenta
  • Immunofluorescent Antibody test of Toxoplasma (IFAT) antigen in placenta
  • PCR for antigen
  • Paired serology for antibodies
22
Q

How is Toxoplasma gondii controlled?

A
  • Control cat population
  • Secure feed stores to prevent access
  • Vaccination
23
Q

Describe the vaccination against Toxoplasma gondii

A
  • Toxovax, live attenuated strain undergoes limited multiplication in host
  • Given at least 3 weeks prior to tupping
  • Not in pregnant animals
24
Q

What are the sources of Toxoplasma gondii human infection?

A
  • Undercooked meat
  • Raw sheep milk
  • Cat faeces in gardens, play grounds, fields etc
  • Lambing (skin wounds)
25
Q

What are the 4 sources of infection of Campylobacter?

A
  • Carrier sheep
  • Aborted material
  • Contaminated feed or water
  • Birds
26
Q

What increases the risk of Campylobacter spread?

A

Intensive management and poor hygiene

27
Q

What are the clinical signs of Campylobacter infection?

A
  • Abortion in last 6 weeks of pregnancy or birth of weak born lambs
  • Usually occurs 1-4 weeks post infection
  • Ewes may become ill with metritis
28
Q

How is Campylobacter diagnosed?

A

Bacterial culture from the placenta, fetal stomach or liver

29
Q

How is Campylobacter controlled?

A
  • Isolate aborting ewes, dispose of material
  • Improve hygiene in lambing sheds
  • Move sheep due to lamb to clean accommodation/pasture
  • No vaccine in UK
30
Q

Listeria monocytogenes disease is associated with which sheep and why?

A

Silage fed

  • Poorly preserved, soil contamination, mouldy allows bacteria to multiply (ph >5.0)
  • Abortion occurs 1-2 weeks after feeding
31
Q

How is Listeria monocytogenes controlled?

A
  • Isolate
  • Remove contaminated feed
  • Antibiotic course for affected ewes
32
Q

Border disease virus is closely related to which 2 other pathogens?

A

Bovine Viral Diarrhoea Virus (BVDV) and Classical Swine Fever

33
Q

Describe transmission and infection routes of border disease virus

A
  • Infection introduced and maintained in flock by persistently infected (PI) BDV virus shedding animals
  • Transmission is by: Oro-nasal route, in utero, or semen of persistently infected rams
34
Q

What are the clinical signs of border disease virus in non-pregnant ewes?

A

Non pregnant ewes exposed no clinical signs

35
Q

What are the clinical signs of border disease virus in pregnant ewes?

A
  • Barren ewes (early embryonic loss) - cause of low scanning percentage
  • Abortions (mid pregnancy infection)
  • Still births, small weak lambs (mid pregnancy infection)
  • Live hairy shaker lambs, (mid pregnancy infection)
  • Birth of persistently infected lambs (PI)
36
Q

How is border disease virus diagnosed?

A
  • Low scanning percentage
  • Clinical signs of hairy shakers being born are often first indicators of problem
  • Post-mortem investigation of abortion
  • Serology from ewes for BDV antibodies (ELISA)
37
Q

How is border disease virus controlled?

A
  • No vaccine
  • Remove persistently infected animals
  • Try and identify PI by PCR
  • Review biosecurity
38
Q

What are the clinical signs of tick borne fever?

A
  • Fever
  • Infertility ewes and rams
  • Abortion
39
Q

How can tick borne fever be controlled?

A
  • Treat with sheep pyrethroid pour on or OP dip before entering tick areas
  • Avoid introduce naïve sheep when pregnant or at tupping time
40
Q

What are the clinical signs of salmonella in sheep?

A
  • Abortion last 1/3 pregnancy
  • Ewes are often systemically ill
  • Can cause abortion storms
41
Q

How can salmonella be treated/controlled in sheep?

A
  • Reduce spread: isolation, disposal of infected material, cleaning and disinfection of pens
  • Antibiotic treatment
  • Review farm hygiene
  • Don’t buy in sheep
  • Don’t mix sheep until after lambing
42
Q

How is Schmallenberg virus transmitted?

A

By midges - Culicoides

43
Q

What are the clinical signs of Schmallenberg virus infection

A
  • Not pregnant then no clinical signs
  • Main clinical sign is foetal malformations
  • Increased embryonic death
44
Q

Give examples of congenital abnormalities that result from Schmallenberg virus infection

A
  • Bent limbs and fixed joints
  • Twisted neck or spine
  • Domed head
  • Short lower jaw
  • Blindness
  • Wobbly
  • Inability to suck
  • Fitting
45
Q

Q fever is caused by which pathogen?

A

Coxiella burnettii

46
Q

How does Coxiella burnettii infection occur?

A

Direct contact and inhalation

47
Q

How is Coxiella burnettii diagnosed?

A

Serology (ELISA), bacterial culture and histopathology of foetal tissues

48
Q

How is Coxiella burnettii controlled?

A
  • Isolation of infected animals, burn contaminated material
  • Oxytetracycline injectable
  • Pasteurisation of milk

Y3 Infectious diseases (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions