Ovine Abortion

Question 1

How is enzootic abortion transmitted?

Answer 1

Shed by a ewe at previous lambing time

Question 2

Abortion agent in enzootic abortion

Answer 2

Chlamydia abortus

Question 3

What will cause a ewe to abort in the last 2 weeks of gestation with intercotyledonary thickening and brown exudate?

Answer 3

Enzootic abortion

Question 4

How is enzootic abortion diagnosed?

Answer 4

Modified Ziehl-Nielson stain on placenta shows red-stained elementary bodies or serology of ewe blood

Question 5

Prevention of enzootic abortion

Answer 5

Care with replacement ewes
Vaccination 3 weeks before tupping

Question 6

Control of enzootic abortion in an outbreak

Answer 6

Isolate the ewe and remove debris
Give dead vaccine to other pregnant ewes or live vaccine 3 weeks before tupping
Oxytetracycline

Question 7

Which abortion agent in ewes is spread by cats?

Answer 7

Toxoplasma gondii (causing toxoplasmosis)

Question 8

Which cause of abortion would you suspect with empty ewes (resorption), mummified/aborted fetuses and weak lambs with white dots on cotyledons?

Answer 8

Toxoplasmosis

Question 9

Diagnosis of toxoplasmosis

Answer 9

Placenta PCR
IFAT on fetal thoracic and abdominal fluid
Serology on ewe blood

Question 10

Control of toxoplasmosis

Answer 10

Vaccination of replacement ewes

Question 11

What causes abortion in the last 6 weeks of pregnancy, weakly lambs and grey areas of necrosis on fetal livers?

Answer 11

Campylobacter fetus fetus and Campylobacter jejuni

Question 12

Source and transmission of campylobacteriosis

Answer 12

Carrier ewe
Mechanical transmission by birds and vermin

Question 13

Diagnosis of campylobacteriosis

Answer 13

Gram smear of placenta and fetal stomach contents, curved gram -ve rods

Question 14

Control of campylobacteriosis in an outbreak

Answer 14

Isolate aborted ewes and remove contaminated bedding

Question 15

Prevention of camplyobacteriosis

Answer 15

Immunity develops after outbreak, expect further outbreak after 4 years
Vaccine can be imported from New Zealand under a special license

Question 16

Salmonella abortive agents in sheep?

Answer 16

S. abortus
S. montevideo
S. dublin

Question 17

How is salmonella transmitted?

Answer 17

Carrier sheep and wild birds

Question 18

Clinical signs of salmonellosis in sheep

Answer 18

Metritis, scour, abortions, weak lambs

Question 19

What would you see on a gram smear of placenta and fetal stomach contents if a sheep had salmonellosis?

Answer 19

Short gram -ve rods

Question 20

What medium should be used for Salmonella culture?

Answer 20

MacConkey’s agar

Question 21

Prevention of salmonellosis in sheep

Answer 21

Cattle vaccine (under cascade)

Question 22

Control of Salmonella outbreak

Answer 22

Isolate aborted ewes
Strict hygiene
Antibiotics

Question 23

Apart from hairy shakers, what clinical signs are seen with Borders disease?

Answer 23

Resorption, mummification, abortion, stillbirths

Question 24

Source of border disease infection

Answer 24

Persistently infected lamb (or calf as ~20% BDV cases are actually cattle BVD)

Question 25

Diagnosis of borders disease

Answer 25

PCR or virus isolation from fetal spleen
Blood from lamb (pre-colostrum)
Ewe serology

Question 26

Prevention of border disease

Answer 26

Avoid mixing pregnant ewes and replacement lambs

Question 27

Control of BDV once it is in a flock

Answer 27

Mix non-pregnant ewes and PI lambs to ensure sero-conversion before pregnancy

Question 28

Is the cattle BVD vaccine effective in sheep?

Answer 28

No