Abortion

Question 1

What are the 4 most important causes of abortion in sheep?

Answer 1

Chlamydophila abortus
Toxoplasmosis
Campylobacter foetus foetus
Salmonella

Question 2

What is the presentation of chlamydophila abortus / endotoxin abortion?

Answer 2

Infected when pregnant - Abortion after 90 days of gestation
Infected when not pregnant - abort next lambing

Introduced by latently infected replacements - shed at oestrus and lambing
Will initially cause a low level of abortion in the first year
Then an abortion storm the next year

Abortion of freshly dead lambs after 90 days of gestation

Question 3

How can you diagnose chlamydophila abortus?

Answer 3

Abortion of well preserved lambs after 90 days of gestation
Submit foetus and placenta to APHA 
- modified Ziehl Nielsen stain 
Culture 
PCR 

If there are no aborted materials

• vaginal swab ewe
• paired serology

Question 4

How can you control a chlamydophila outbreak?

Answer 4

Isolate the ewe
Submit foetus and placenta
Bedding burnt
Pen disinfected 
Consider zoonotic risk 

Treat all animals yet to lamb will long acting oxytetracycline and repeat in 2w

Closed flock
Vaccinate - enzovax

Question 5

How is toxoplasma Gondii introduced into a flock?

Answer 5

Cats - shed oocysts in faces - contaminate the feed and water of sheep

Question 6

How does toxoplasmosis present?

Answer 6

Non-pregnant - become immune
Early pregnancy - foetal resorption
IMPORTANT CAUSE OF A LOW SCANNING PERCENTAGE
Mid pregnancy - foetal mummification / retardation
Late pregnancy - abortion of freshly dead lambs, birth of weak lambs, birth of immune lambs

Question 7

How can you diagnose toxoplasmosis?

Answer 7

Serology from the foetus and placenta
Frosted strawberry cotyledons
Histo-pathology of the foetus and placenta
PCR

Question 8

How can you control toxoplasmosis?

Answer 8

Control cat and rodent population
Secure feed stores
Toxovax - 3 weeks pre-tupping

Question 9

How does salmonella abortus ovis present?

Answer 9

Healthy carrier sheep
Abortion in the last trimester
Sheep systemically ill after - metritis
Abortion storm

Question 10

How can you diagnose salmonella abortus ovis?

Answer 10

Isolation of the organism from foetal stomach and placenta

Question 11

How can you treat a flock with salmonella abortus ovis?

Answer 11

Whole flock treatment with long acting oxytetracycline, repeated in 7-10 days

Individual sick sheep receives both oxytetracycline and NSAIDs

Question 12

How should a farmer control the outbreak?

Answer 12

Secure feed stores - keep out birds
Don’t buy in sheep
Or don’t mix bought in sheep until after lambing

Isolate affected ewes, burn bedding, disinfect pens
Zoonotic risk

Question 13

How does campylobacter present?

Answer 13

Abortion in the last 6 weeks of pregnancy

Some ewes may be ill with metritis

Question 14

What are the sources of campylobacter?

Answer 14

Carrier sheep
Birds
Aborted material
Contaminated feed and water

Question 15

How can you diagnose campylobacter?

Answer 15

Smear and culture from placenta / foetal stomach and liver

Question 16

How can you control campylobacter?

Answer 16

Isolate aborting ewes
Dispose of aborted material and burn bedding
Disinfect

No vaccine

Treat affected sheep with pen strep (good for campy) and NSAID
Closed flock

Question 17

How does border disease virus present?

Answer 17

Infection before 60 days of gestation - foetal resorption
- or 50% can be born appearing normal

Infection 60-85 days -
hairy shakers - long limbs and cerebellar hypoplasia

Infection at more than 85 days - seropositive lamb born

Question 18

How can you diagnose border disease?

Answer 18

Antigen test hairy shakers at 3 months
Submitted dead lambs and blood from ewes to VLA
Histopathology 
Virus isolation
Ewe serology

Question 19

How should you control border disease?

Answer 19

Do not breed from entire lamb crop
Or
Test the whole flock for persistently infected animals and cull

Question 20

What can you use to treat listeria?

Answer 20

Penicillin

Oxytetracycline