Sheep - Infectious Disease

Question 1

infectious causes of abortion or stillbirth

Answer 1

brucellosis - notifiable
campylobacter
toxoplasma gondii
listeria
salmonella
chlamydia (enzootic abortion)

Question 2

chlamydia signs

Answer 2

late pregnancy abortion
weak or stillborn lambs
joint problems
conjunctivitis

Question 3

chlamydia transmission and risk factors

Answer 3

exposure to infected birthing fluids at lambing time

new sheep introduced to flock
poor hygiene and management of birthing products
contact with cattle
poor manure management

vax available

Question 4

chlamydia diagnosis

Answer 4

inflamed placenta
serum ELISA
histopath analysis of abortion products
PCR on abortion products

Question 5

chlamydia treatment

Answer 5

abx - systemic - log acting oxytetracycline

Question 6

brucellosis signs

Answer 6

rams - lesions on epididymis and scrotum, swollen testes, low quality semen

abortion
perinatal lamb death
swollen udders
reduced milk production
fever arthritis
infertility

Question 7

brucellosis transmission and risk factors

Answer 7

semen - ram to ewe in natural breeding - most common
milk and vaginal discharge
shared equipment - mainly shearing

risk factors -
larger flocks
natural breeding
older ewes
history of abortion
poor bcs

Question 8

brucellosis treatment

Answer 8

none
notifiable
zoonotic

Question 9

brucellosis diagnosis

Answer 9

quick screening test - less sensitive
serum agglutination - slower more expensive but more specific
serum culture
PCR

need 2 consecutive negative tests to be confirmed clear again

Question 10

campylobacter signs

Answer 10

late stage abortion pregnancy
weak lambs
red brown vulval discharge
stillbirths
sometimes a light diarrhoea

Question 11

campylobacter diagnosis

Answer 11

pm of abortion products - bacteria in smear from stomach contents of aborted lambs
pcr - faster but less accurate

Question 12

campylobacter risk factors

Answer 12

high stocking density
biosecurity
introduction of ewes that haven’t been exposed or infected ewes into flocks that havent been exposed
contact with abortion materials
increased risk in spring and summer
long term carriers - introduce infection into flock between seasons
persistance of low numbers of bacteria in sheeps gall bladder and intestine

Question 13

campylobacter treatment

Answer 13

abx
biosecurity
vax avaiable for prevention
reduce stocking density

Question 14

listeria signs

Answer 14

depression
disorientation, circling
horners
difficulty eating
abortion
sudden death

Question 15

listeria transmission and risk factors

Answer 15

contaminated feed - badly stored silage
direct contact
water sources

risk factors -
poor silage storage
contaminated soil, manure, and water
stress
compromised immunity from other conditions - mastitis esp

Question 16

listeria diagnosis

Answer 16

CSF analysis
pm - brain tissue

Question 17

listeria treatment

Answer 17

aggressive and early abx treatment
steroid injection in addition shows to be helpful
supportive care to treat signs
identify sources of contaminatipn

Question 18

toxoplasma gondii signs

Answer 18

abortion
stillbirth
mummified foetuses
infertility
weak lambs

Question 19

toxoplasma gondii transmission and risk factors

Answer 19

shed in cat feces - no sheep to sheep transmission

zoonotic

risk factors -
cats
contaminated food and water
poor biosecurity
age - older sheep more susceptible

Question 20

toxoplasma gondii diagnosis

Answer 20

pm - foetal material - strawberry cotyledons on placenta and histopathology of fetal brain

ELISA on ewes - but antibodies may persist so may not be infected anymore and still test positive

Question 21

toxoplasma gondii treatment

Answer 21

no treatment

prevention via vax, biosecurity and keep cats out best

Question 22

infectious foot conditions

Answer 22

foot rot
contagious ovine digital dermatitis (CODD)

Question 23

Footrot transmission and risk factors

Answer 23

bacteria entering through injury to foot

risk factors -
wet conditions
rocky ground - foot injury allowing entry
dirty environment
high stocking density
introduction of new sheep

Question 24

footrot signs

Answer 24

lameness
reddening and swelling - interdigital
foul smell
may ooze grey pus -pasty
lifting at skin-horn junction
underrunning/separation of horn at heel

Question 25

foot rot diagnosis

Answer 25

signs and environment - multiple affected, severe lameness, wet conditions, smelly grey pus

Question 26

foot rot treatment

Answer 26

foot baths topical and systemic abx nsaids isolation of affected keep off wet fields manure management dont trim

Question 27

infectious causes of diarrhoea

Answer 27

e coli salmonella rotavirus coccidiodis endoparasites schmallenberg crypto giardia clostridia perfringens

Question 28

lamb scours prevention

Answer 28

lambing hygiene - clean lambing pens, clean bedding good ewe bcs dagging and shearing of ewes pre lambing to prevent contamination colostrum management limit stress good nutrition good stocking density vaccine programme for pregnant ewes - clostridal diseases standard, e coli and crypto also available

Question 29

lamb scours treatment

Answer 29

oral rehydration and electrolyte supplementation tube feeding abx parasite treatment if identified as cause isolation of affected

Question 30

lamb scours diagnosis

Answer 30

fecal testing to identify pathogens

Question 31

common infectious respiratory pathogens

Answer 31

bacteria - mycoplasma, pasteurella, manhheimia haemolytica viral - maedi visna, jaagsietke (OPA) lungworm

Question 32

lamb pneumonia causes

Answer 32

mannhaemia pasteurella bibersteinia other bacteria PI3 lungworm infection from environment, aerosol spread, direct contact, weak lambs

Question 33

lamb pneumonia prevention

Answer 33

ventilation reducing dust colostrum management ewe vaccines - antibodies in colostrum lambs also vaxed reduced stress proper nutrition biosecurity care when drenching - reduces chance of aspiratoin pneumonia age grouping isolation of lambs showing signs

Question 34

lamb pneumonia diagnosis

Answer 34

signs pcr usually a combination of pathogens

Question 35

lamb pneumonia treatment

Answer 35

abx nsaids managemtn changes isolation supportive care - feeding, fluids

Question 36

maedi visna signs

Answer 36

resp signs - dyspnoea, pneumonia neuro - progressive weakness, ataxia, circling, tremors chronic wasting iceberg disease - don't see signs until late stages, at that point likely a lot of subclin cases in flock

Question 37

maedi visna transmission and risk factors

Answer 37

milk, colostrum or respiratory secretions of infected ewes

Question 38

maedi visna diagnosis

Answer 38

pm - brain changes serum elisa - antibodies

Question 39

maedi visna treatment

Answer 39

no real treatment - test and cull

Question 40

jaagsietke (OPA) signs

Answer 40

dyspnoea frothy nasal discharge weight loss sudden deaths iceberg disease

Question 41

jaagsietke (OPA) transmission

Answer 41

aerosol milk and colostrum

Question 42

jaagsietke (OPA) diagnosis

Answer 42

wheelbarrow test - froth out of nose pm - lung tissue lung wash PCR

Question 43

jaagsietke (OPA) treatment

Answer 43

Test and cull

Question 44

clostridial diseases

Answer 44

lamb dystentry pulpy kidney braxy black disease (infectious necrotic hepatitis) blackleg tetanus

Question 45

clostridial disease signs

Answer 45

can cause sudden death lamb dysentry - bloody diarrhoea pulpy kidney - sudden death, rapid bloat and putrification of carcass braxy - depression, fever, rapid putrefication of carcass black disease - infectious necrotic hepatitis - may see jaundice, jaundice and blood in urine at pm blackleg - sudden lameness, limb cold them warm tetanus - stiffness, lockjaw, 3rd eyelid protrusion

Question 46

clostridial disease diagnosis

Question 47

clostridial disease prevention

Answer 47

Vax - ewes yearly, lambs at 3 weeks supplementary boosters in flocks with high pasteurella liver fluke control colostrum management stress reduction

Question 48

clostridial disease treatment

Answer 48

limited - abx not usually effective supportive - fluids, monitoring, pain relief usually PTS

Question 49

coccidiosis signs

Answer 49

usually in lambs - 1-6 months diarrhoea - may have blood or mucus straining or rectal prolapse weight loss or wasting dehydration dullness vocalistion death

Question 50

coccidiosis transmission

Answer 50

feco-oral

Question 51

coccidiosis prevention

Answer 51

biosecurity - decrease environmental contamination limit stocking density care to keep contamination out of feed - raised or fencing to separate feeding surface to keep feces out of it rotate pastures provide easily accessible shelter, feed, water etc to reduce stress keep water clean

Question 52

coccidiosis diagnosis

Answer 52

FWEC - microscope examination of feces - oocysts pm - oocysts in intestine sections of diseased lambs

Question 53

coccidiosis treatment

Question 54

common in lambs

Question 55

notifiable

Question 56

zoonotic