Small ruminants 2/2

Question 1

Contagious agalactia is a contagious disease of sheep and goats, caused mainly by Mycoplasma agalactiae, and is characterized by (3)

Answer 1

mastitis, polyarthritis and keratoconjunctivitis.

Question 1

Causative agent of contagious agalactia.
gram status

Answer 1

Mycoplasma agalactiae

But also other mycoplasma spp.:
M. capricolum subsp. capricolum
M. putrefaciens

M. mycoides subsp. capri
M. mycoides subsp. mycoides large colony (LC)

Gram neg. of course

Question 2

Survival of mycoplasma.

Answer 2

Relatively fragile in the environment.

Can produce biofilm – protects from heat and drying, enhance the survival.

Question 3

Host range of contagious agalactia.

Answer 3

sheep and goats

M. agalactiae - both species

M. capricolum subsp. capricolum &
M. mycoides subsp. capri &
M. mycoides subsp. mycoides large colony (LC): Mainly goats, rarely sheep

M. putrefaciens – only goats

Question 4

Transmission of contagious agalactia.

Answer 4

Excretion: all bodily fluids basically.

Direct contact
Indirect contact (feed, water)
Fomites
Aerosols

Route: alimentary, respiratory, through teat openings.

Question 5

IP of contagious agalactia.

Answer 5

1-8 weeks

Question 6

Clinical signs of contagious agalactia with M.agalactiae.

Answer 6

Clinical signs more severe in goats than in sheep.

Acute:
Transient fever, malaise, inappetence and mastitis & Agalactia.
Udder can atrophy and fibrose too.
Polyarthritis, keratoconjunctivitis poss. too.

Abortions in chronic cases

Question 7

Contagious agalactia can be what forms/courses?

Answer 7

Asymptomatic, acute, chronic.

Question 8

And what 3 main conditions can the acute form of disease caused by M.agalactiae produce?

Answer 8

mastitis
polyarthritis
keratoconjunctivitis

Question 9

Clinical signs of Mycoplasma spp. other than M.agalactiae - in GOATS.

Answer 9

M. mycoides mycoides LC, M. mycoides capri, M. capricolum capricolum, M. putrefaciens:

Mainly in goats
Acute or hyperacute

Pneumonia and/or septicemia with fever, prostration, anorexia, generalized malaise.

Mortality is high, Sudden deaths

Mastitis, arthritis, keratoconjunctivitis (tho No ocular signs with M. putrefaciens).

Abortion
Genital lesions

Question 10

Clinical signs of Mycoplasma spp. other than M.agalactiae - in SHEEP.

Answer 10

M. mycoides mycoides LC: vulvovaginitis, balanoposthitis (glans & prepuce inflamm.)

M. capricolum capricolum: genital lesions

Question 11

Post mortem signs of contagious agalactia.

Answer 11

Signs of septicemia, pneumonia, mastitis, arthritis and/or keratoconjunctivitis.

Some cases: genital lesions such as vulvovaginitis, cystic catarrhal metritis and/or salpingitis; balanoposthitis or testicular degeneration.

Question 12

Suspect contagious agalactia when

Answer 12

keratoconjunctivitis and arthritis presents in a herd with mastitis and decreased milk production, particularly when these signs develop near the time of parturition.

Question 13

Material for diagnosis of contagious agalactia.

Answer 13

Nasal, conjunctival swabs
Joint fluid aspiration
Milk
Blood
Tissue samples – udder (and associated LNs), lung

Question 14

Lab analyses for diagnosis of contagious agalactia.

Answer 14

Isolation of the organism – culture

Identifying the agent – PCR

Serology (complement fixation, ELISA) – for herd testing

Question 15

Tx of contagious agalactia.

Answer 15

Tx: ABs

Results in symptomatic improvement; not so effective in chronic joint infections or keratoconjunctivitis.

May not eliminate the carriers!

Question 16

Prevention & control of contagious agalactia.

Answer 16

good management and hygiene

Isolation of the sick
Milking animals should be separated from the young

Regular testing + culling/isolation of the sick

Vaccination (prevents symptoms but not infection)

Question 17

Ovine pulmonary adenocarcinoma is a contagious disease of sheep, caused by retrovirus, and is characterized by

Answer 17

pulmonary neoplasia.

Question 18

Causative agent for Ovine pulmonary adenocarcinoma.
genus
family
DNA type

Answer 18

Jaagsiekte sheep retrovirus (JSRV)
Also known as: pulmonary adenomatosis virus.

Genus Betaretrovirus,
family Retroviridae
RNA virus

Question 19

What is Jaagsiekte sheep retrovirus (JSRV) also known as:

Answer 19

pulmonary adenomatosis virus

Question 20

Survival of JSRV.

Answer 20

Jaagsiekte sheep retrovirus (JSRV)

Does not survive for long in the environment.

Susceptible to most common disinfectants.

Question 21

Host range of Ovine pulmonary adenocarcinoma.

Answer 21

domesticated sheep

Most cases in sheep >2 years of age
(peaks: 3-4 years)

Question 22

Morbidity & mortality of Ovine pulmonary adenocarcinoma.

Answer 22

Recently infected herds: high, <80% mortality

Longer presence: 2-5% (<20%) mortality

Incidence rate much higher than morbidity – most sheep do not develop tumors during their commercial lifespan.

Question 23

Transmission of Ovine pulmonary adenocarcinoma.

Answer 23

Excretion: respiratory exudates. Also maybe milk.

Direct contact – aerosols, droplets

Route: respiratory

Virus can be found in tumors, lung fluids, peripheral blood leukocytes and lymphoid organs.

Before tumor development: virus is detected in lymphoreticular cells.

Question 24

IP of Ovine pulmonary adenocarcinoma.

Answer 24

IP: 6 months to 3 years Age-dependent – longer in older sheep.

Question 25

Clinical signs of Ovine pulmonary adenocarcinoma.

Answer 25

Clinical signs occur ONLY in animals that have developed tumors. Progressive emaciation, weight loss, respiratory compromise. Thick mucus discharge from nostrils; copious frothy exudate if head is lowered. Moist audible rales on auscultation. Signs are slowly progressive toward severe dyspnea. Death in days to few months, often due secondary bacterial pneumonia.

Question 26

Post mortem signs of Ovine pulmonary adenocarcinoma.

Answer 26

Lungs are enlarged. In advanced cases: they do not collapse upon opening the chest cavity. Frothy fluid in trachea and bronchi Tumors in lungs Apical, cardiac and ventral portions of the diaphragmatic notches. Vary from small nodules to solid masses. Clearly demarcated, firm, gray or pinkish-gray. On cut surfaces: glistening and granular, frothy fluid expressed. Often secondary pneumonia and fibrinous pleuritis. Tumor metastasis only to nearby LNs.

Question 27

Suspect Ovine pulmonary adenocarcinoma when

Answer 27

chronic respiratory signs, particularly in 2-4-year-old animals with frothy mucoid discharge from the nostrils.

Question 28

What positional test can you do on live sheep to diagnose ovine pulmonary adenocarcinoma?

Answer 28

“Wheelbarrow test” – to check for excess fluid in the lungs

Question 29

Material for diagnosis of ovine pulmonary adenocarcinoma

Answer 29

Tumor (lung and regional LNs) Lung fluid Blood (peripheral) Colostrum, milk

Question 30

Lab analyses for diagnosis of ovine pulmonary adenocarcinoma

Answer 30

Histopathology Detecting viral antigens Detecting viral RNA – PCR No culture and no serology! Absence of an immunological response.

Question 31

Tx of ovine pulmonary adenocarcinoma.

Answer 31

No Tx No vaccine

Question 32

Prevention & control of ovine pulmonary adenocarcinoma.

Answer 32

Replacement from flocks with no dz history. To reduce losses: remove affected sheep and the offspring of infected ewes. Does not eradicate the dz from flock! Good disinfection and general hygiene.