FOP 4 OviCap notes + presentation

Question 1

in sheep the most common location for lesions is the:

Answer 1

placenta

Question 2

main lesions associated with sheep FOP

Answer 2

Placentitis and multifocal placental cotyledonary necrosis are the main lesions.

Question 3

how many sheep abortions can be diagnosed?

Answer 3

Data from diagnostic laboratories indicates that about 50% of submissions yield an infectious cause.

Question 4

The big four causes of infectious abortion in sheep are:

Answer 4

-Chlamydia abortus
-Campylobacter sp
-Toxoplasma gondii
-Coxiella burnetii

Question 5

is chlamydia abortus zoonotic?

Answer 5

yes

Question 6

lesion associated with chlamydia abortus

Answer 6

chronic placentitis

Question 7

how do ewes get infected with chlamydia abortus? What is the source of the agent?

Answer 7

-through mucous membranes including those of the mouth, conjunctiva and reproductive tract.
-The source of the agent is aborted fetuses and uterine discharge, vaginal secretions of carrier ewes at estrus or there is spread through the prepuce and semen of rams (at least temporarily).

Question 8

after exposure to chlamydia abortus, where can the infectious agent be detected and for how long? does the sheep develp antibodies?

How does the organism move through the body of the sheep and cause FOP? what are the signs of infection? how does immunity arise?

Answer 8

After exposure to Chlamydia abortus, sheep develop antibody, but infection can be detected for a month or more as interstitial pneumonia or focal hepatitis.

-The organism can be found in the mononuclear cells of the uterus.
>From there they infect the epithelial cells of the placentomes, and control of infection is by neutrophilic infiltrates.
>Trophoblasts in the periplacentomal region become infected and there is a logarithmic increase in numbers, with subsequent necrosis and inflammation of the placenta.
>Maternal inflammation becomes restricted to lymphocytic inflammation around the endometrial cells of the uterine glands. It is assumed that this immune reaction prevents infection of the placenta in subsequent pregnancies.

Question 9

incubation of chlamydia abortus during gestation? when will the ewe abort? how many times?

Answer 9

The incubation period during gestation is very long - - from 50 to 90 days. If a ewe is infected early in gestation, she will abort in the same gestation (gestation is 145 days). If infection occurs in late gestation she will abort during the next pregnancy. In general, once a ewe aborts, she will not abort a second time. She may remain a carrier for several years however.

Question 10

incubation of chlamydia abortus during gestation? when will the ewe abort? how many times?

Answer 10

The incubation period during gestation is very long - - from 50 to 90 days. If a ewe is infected early in gestation, she will abort in the same gestation (gestation is 145 days). If infection occurs in late gestation she will abort during the next pregnancy. In general, once a ewe aborts, she will not abort a second time. She may remain a carrier for several years however.

Question 11

common way that chlamydia abortus is introduced to a new flock? what is the common consequnce?

Answer 11

Introduction of infected replacements is a common way to introduce infection into a naïve flock and to begin an abortion storm. In the first year following introduction there may be a few animals abort but most of the flock will become infected. Abortions normally occur the following year with up to 75% of pregnant ewes aborting. In subsequent years the disease becomes enzootic and only first time lambers abort.

Question 12

how can we diagnose chlamydia abortus? what are drawbacks to our methods?

Answer 12

Diagnosis of infection can be made on aborted tissues, and serology is possible but it is very expensive. There is a low level of false positives and there is some cross reaction with Chlamydia pecorum, a Chlamydia found in the faeces.

Question 13

how can we treat chlamydia abortus? what are drawbacks?

Answer 13

-Treatment in the face of an outbreak of Chlamydia abortion includes the use of long acting oxytetracycline. This should be repeated every 10 to 14 days.
>Orally administered tetracycline is an alternative.

> Because of the long incubation period, there is usually a poor to moderate efficacy of this treatment.

Question 14

is there a vaccine protocol for chlamydia abortus?

Answer 14

Vaccination is possible with a killed vaccine but it is not readily available and has a variable efficacy.

Question 15

Campylobacter fetus subsp fetus
and
Campylobacter jejuni
cause what in sheep?

Answer 15

intercotyledonary placentitis with abortion and stillbirths, and the birth of weak lambs.

Question 16

how do ewes become infected with campylobacter and where do carriers harbour the bacteria?

Answer 16

Ewes are infected through the feco-oral route and carriers have the bacterium within the gall bladder.

Question 17

source of infection for ewes of campylobacter? how do outbreaks compare with chlamydiosis?

Answer 17

Aborted fetuses and placentae are a source of infection, but outbreaks are not as dramatic as with chlamydiosis.

Question 18

incubation of camplylobacter and result for abortion timing

Answer 18

The incubation is 7 to 60 days, and abortion can ‘cycle’ within a lambing season.

Question 19

how can we treat and prevent abortions in ewes due to campylobacter?

Answer 19

Control of abortion in the face of an outbreak can be achieved with a good degree of success with long acting oxytetracycline or oral tetracycline. There is a vaccine for prevention (given prior to breeding) and control (in the face of an outbreak).

Question 20

lesions associated with ovine abortion due to toxoplasma gondii

Answer 20

focal necrosis in the cotyledon and histologic changes in the brain of fetuses.

Question 21

source of infection of toxoplasma gondii? will ewes become immune?

Answer 21

The source of infection is usually infected cats which pass oocysts in their faeces for approximately seven days. Oocysts can remain infective for six months. Naive ewes will develop a protective immunity but if they are pregnant, infection of the cotyledon will result in abortion.

Question 22

how can we control infections of toxoplasma gondii? difficulties?

Answer 22

Control of toxoplasmosis involves removing the source of oocysts. Control of rodents and cats and their access to feed and pasture is particularly important. Even this will not guarantee complete control as purchased feed may be contaminated. Feral cats are very difficult to control also!
>no kittens, have cats use litter

Question 23

prevention measures for toxoplasma gondii

Answer 23

Prevention of infection or abortion can be achieved by including monensin or decoquinate in the feed throughout gestation.

Question 24

is Ovine brucellosis common in canada or the US?

Answer 24

-rare in the eastern United States and Canada.
-It is an important cause of disease in rams in a both Western US and Western Canada.

Question 25

presenting condition for brucella ovis in rams

Answer 25

epididymitis

Question 26

is abortion due to brucella ovis common?

Answer 26

-in most flocks, abortion occurs only occasionally

Question 27

how is Brucella ovis passed on and can it be cleared easily? can it cause abortion storms?

Answer 27

Infection of ewes is usually by infected rams at mating and the infection is cleared spontaneously. It is possible for outbreaks to occur and to have an abortion storm of up to 70%.

Question 28

how is brucella ovis generally introduced to a flock?

Answer 28

usually occurs with the introduction of an infected ram.

Question 29

how can we control/prevent brucella ovis?

Answer 29

Control of the disease is the best achieved by elimination of infected rams using scrotal palpation and serology outside of the breeding season.
-In flocks that are heavily infected, vaccination may be helpful but it is only available in the USA.
-It is important to prevent infection and this requires purchasing rams only from flocks known to be Brucella free.

Question 30

what is Border Disease? what other disease is it closely related to?

Answer 30

Pestivirus D (Border disease virus; BDV) and Pestivirus A, B (Bovine Viral Diarrhea Virus; BVDV) are very closely related, as are the diseases they cause.

Question 31

if a pregnant ewe is infected with border disease, what will result?

Answer 31

Infection of a pregnant ewe can result in fetal loss, birth of weak lambs or birth of lambs that are immune.

> Infection at less than 65 days of gestation results in embryonic death.
Infection at 65 to 85 days of gestation can result in the birth of a persistently infected lamb that may be weak, have a hairy coat and shake (thus the clinical manifestation of a “hairy shaker”).
Ewes infected after 85 days of gestation will give birth to normal lambs with titres to BDV.

Question 32

How can we control/prevent border disease?
How can we identify persistently infected animals?
How effective are vaccines?

Answer 32

The control of border disease revolves around reducing exposure of naive individuals during pregnancy.

> Persistently infected sheep provide a source of infection so identifying and removing them from the flock is essential.
Border disease is a self-limiting disease if persistently infected animals are identified and removed.
They can be identified by virus isolation from the blood (buffy coat) of infected animals.
Vaccination of ewes with a killed BVDV vaccine is not effective as there is no cross protection.

Question 33

what is the agent behind Q fever? What species are affected?

Answer 33

Coxiella burnetii (Q fever) is a very important disease of sheep and goats, and especially of people.
>It is less common in sheep

Question 34

characteristics of Coxiella burnetii: gram stain, environment, infectiousness

Answer 34

-It is an obligate intracellular gram-negative bacterium
-It is highly resistant to physical and chemical degradation, and is infective in very low doses – as low as one infectious particle – making it the most infectious agent known.

Question 35

how is Coxiella burnetti transmitted?

Answer 35

Aerosolisation as ‘dust’ is significant. Naïve animals are infected by aerosol or from infected unpasteurised milk.

Question 36

once an animal has ingested a Coxiella burnetti organism, how does the infection proceed? where will the bacteria go and what symptoms and lesions will they cause?
How do carriers shed the infection, and when during their lives?

Answer 36

After primary replication in local lymph nodes, it becomes bacteraemic and localizes in the mammary gland and pregnant uterus.
>It can be found in large numbers in amniotic fluid and in the placental membranes, especially trophoblasts.
> It will cause placentitis and abortion, but some placentas have no lesions.
>Some animals become carriers and shed the organism in milk and in uterine fluids. Shedding in the periparturient period is especially common.

Question 37

if coxielly burnetti is present in a goat herd, what can we expect in terms of abortions? Why is this organism hard to get rid of?

Answer 37

A naive goat herd may have up to 50% of pregnant does abort.
>There is a very significant zoonotic risk. Goats can be persistently infected and shed the organism at subsequent kidding.
>Because the organism can be highly infective in a dried state, it is dust born, and barns and sheds become contaminated and can be potentially infective for many years.
>Infection of the premises can also occur with carrier animals including sheep, cattle, cats, birds and other wildlife.

Question 38

how can we control and prevent coxiella burnetti transmission? what people should be especially cautious if there is a risk of this organism being present?

Answer 38

Treatment in the face of an abortion storm can be achieved through the use of oxytetracycline as with chlamydiosis.
>Special precautions are required for any infective environment and when assisting kidding.
>The use of gloves, appropriate masks and eye protection while assisting in kidding or cleaning barns is strongly advised.
>Children, elderly and pregnant individuals should stay out of the barn.

Question 39

when might a goat abort due to luteolysis?

Answer 39

prone to luteolysis following stress and or trauma such as dog or coyote attacks.
-goats maintain their CL for the entire pregnancy and thus are more prone to abortions of this nature

Question 40

4 most common infectoious agents causing FOP in sheep and goats? which are zoonotic?

Answer 40

-campylobacter
-coxiella (zoonotic)
-chlamydia (zoonotic)
-toxoplasmosis

Question 41

which organism of the four most common for FOP in sheep and goats is especially problematic for goats?

Answer 41

coxiella

Question 42

frequency of diagnosis of FOP cause in ovine/caprine? what is usually implicated?

Answer 42

-diagnose 50% of cases
-almost all due to infection

Question 43

sign of iodine deficiency in fetus?
where is it more common?

Answer 43

-goitre
-myxedema of skin (swelling/thickening of skin due to hypothyroid)
-alopecia

> omre common in great lakes basin

Question 44

deformities of fetal lambs/kids:
what causes them?

Answer 44

-cyclopia
>Veratrum californicum (d14), poisonous plant

-arthrogryposis
>Cache Valley orthobunyavirus

?(-anencephaly
>Cache Valley orthobunyavirus)?

The symptoms the fetus develops from CVV infection are largely age dependent. At less than 28 days of gestation, the embryo usually dies and is reabsorbed by the mother.[22] Between 28 and 45 days of gestation, infection leads to malformations in the developing fetus and occasionally leads to abortions.

Question 45

regional/large mutlifocal hepatic necrosis in the ovine/caprine fetus is due to what pathogens?

Answer 45

campylobacter: C. jejuni, C. fetus fetus, C. fetus venerealis
Helicobacter sp.

Question 46

small multifocal hepatic necrosis in fetal lambs/kids is due to what pathogens?

Answer 46

listeria monocytogenes

Question 47

most inflammatory lesions of the ovine/caprine placenta start from where?

Answer 47

cotyledons

Question 48

pathogenesis of ovine/caprine placentitis?

Answer 48

-exposure of mucous membranes
-local proliferation
-bacteremia
-localize in endometrium/placenta, fetomaternal interface
-trophoblasts around placentome especially infected
-logarithmic growth of organism
-necrosis, neutrophilic inflammation
-failure of pregnancy

Question 49

incubation time of chlamydia?

Answer 49

50-90 days

Question 50

incubation time of campylobacter?

Answer 50

7-60 days

Question 51

result of infection of pregrant ewe with toxoplamsa gondii

Answer 51

-abortion with characteristic lesions, mummification, stillbirth, weak lambs

Question 52

how do sheep get infected with toxoplasma gondii?

Answer 52

contaminated feed - stored and pasture