|
|
Epidemiology |
Laboratory Findings |
|
Disease |
Transmission |
Time of Abortion |
Clinical findings |
Foetus |
Diagnosis |
Enzootic abortion
(Chlamydia psittaci) |
Ingestion. Carriers contaninate environment |
Last 2 – 3 weeks |
Illness before. Retained placenta and metritis after
abortion |
Chlamydia org. in foetal cotyledons. Lymphoid
hyperplasia. Oedema |
Smears (Gimenez) PCR test. Isolation. Histopathology |
Campylobacter
fetus fetus |
Ingestion |
2 months on-wards |
Metritis in ewes after abortion. Necrotic placentitis |
Organisms in stomach . Necrotic hepatitis. Fibrinous
peritonitis |
Smears (Gram stain). Isolation need special media. FA
test |
Ovine brucellosis
(B.
ovis) |
Coitus. Rams are carriers & infected for years |
Late or still-born. Abortion rare |
Epididymitis in rams. In ewes rare abortions. Fib-rinous
placentitis |
Organisms in foetal stomach and placenta.
Bronchopneumonia |
Complement fixation test. Smears (Stamp’s). Isolation |
|
Brucella melitensis
and
B. abortus |
Ingestion |
Late in gestation |
Sporadic outbrakes of abortions. Endometritis. Necrotic
placentitis |
Placentitis. Pneumonia in foetus. Autolytic. Organisms in
stomach |
Culture stomach contents. Smear (Stamp's). Serology |
Listeriosis
(L.
monocytogenes) |
Probably ingestion & wounds in mouth. |
3 m - term & neo-natal deaths. |
Retained placenta and metritis. Septicemia in some ewes |
No lesions in foetus. Organisms in stomach Septicaemia
in lambs |
Isolation. Histopathology. |
Salmonellosis
(S.abortus ovis
and S.dublin
etc.) |
Ingestion |
Last 6 weeks |
Metritis after abortion severe. S dublin ewes die more
regularly. |
Septicaemia. Some severely decomposed. |
Isolation from foetus & ewes. |
Toxoplasmosis
T. gondii |
Ingestion from feline faeces |
Late or stillbirths |
Abortion, stillbirths and neonatal mortality. Ewes
healthy |
Multiple small necrotic foci in foetal cotyledons. Oedema
of subcutis |
Cytology Histopathology. Histochemistry on formalin fixed
tissues. |
Coxiella burnetii
Q fever |
Tick transmitted or contact with tick faeces |
Any time but usually seen late |
Subclinical disease. Abortion storms most common in
goats. Up to 50% may abort |
Cotyledon necrosis. Exudate on thickened placenta.
Foetus normal |
Modified Ziehl Neelsen stain on placental smears.
Indirect FA test. Histopathology |
|
Rift valley fever |
Insect born. Sporadic epidemic |
Usually late |
Abortion and hepatitis Heavy mortality in lambs. Sick
adult sheep Zoonosis |
Multifocal - pannecrosis of liver, general petechia,
oedema of gall bladder. Icterus. |
Isolation. Serology. Histopathology. Immunoperoxidase
test on formalin fixed tissue |
|
Wesselsbron disease |
Insect borne (Sporadic) Endemic in RSA |
Usually late |
Sporadic epizootic abortions. Sick adult sheep |
Icterus. Hepatomegaly, multifocal hepatic necrosis.
Petechia of the abomasum etc. |
Isolation.Histopathology Immunoperoxidose test on
formalin fixed tissue. Serology |
|
Cytoecetes (Ehrlichia) phagocytophilia. |
Tick born fever |
2 - 8 days after fever |
Temp 40-42 C followed by abortion. Tick infested
pasture |
Non specific. Rare mummification |
Cytology. Haematology |
