Page 469 - The Veterinary Laboratory and Field Manual 3rd Edition

406 Susan C. Cork

2 Perform a full necropsy on the dead foetus suspect poison (some plants and mycotoxins
and/or dam – details of any gross findings may cause abortion).
should be recorded on the sample submission
forms (see Appendix 2). Table 10.2 outlines some common causes of
3 From a live dam collect vaginal swabs, a abortion in cattle. Common causes of abortion
serum sample, milk, blood smear, whole in pigs are outlined in Figure 10.1. Note that, in
blood/serum. some cases, especially where a flock or herd has
4 If indicated, send other samples, for example, had previous exposure to a disease, the clinical
faecal smear, smear of any discharge mate- and epidemiological picture may differ from the
rial, faecal sample for culture, or feed sample/ typical presentation reported in text books.

Table 10.2 Some infectious causes of abortion in cattle.

disease agent Clinical Time of disease in the Placental lesions Samples to
features abortion foetus collect
Brucella abortus Abortion (up 6 months May develop Necrosis of Foetal stomach
to 90% in pneumonia cotyledons, contents,
susceptible opacity of placenta (fresh/
herd)/or no placenta and fixed), milk,
apparent oedematous semen; paired
effect, mastitis serum samples
Trichomonas Infertility, 2–4 months Rotten Serous or Cervical mucous,
foetus return to macerated flocculant foetal stomach
service at foetus covered discharge from contents,
4–5 months, in flocculant the uterus and uterine exudates
abortion and/ material over the placenta (smears must be
or pyometra examined when
(5–30% of fresh)
herd affected)
Campylobacter Infertility, 5–6 months Flecks of pus Semi-opaque Foetal stomach
foetus irregular seen over surface over contents, fresh/
oestrous the visceral the placenta, fixed tissue
cycles, peritoneum petechiation and and placenta,
abortion localized oedema discharges for
(2–20% of culture/smears
herd affected)
Leptospira Abortion at > 6 months Perinatal deaths Avascular Serum (paired)
Pomona, L. any stage are common, placenta, from dam and
hardjo during the the dam may atonic yellow other animals in
acute febrile develop mastitis cotyledons, the herd, culture
phase of with red milk brown fluid foetal stomach
infection, 25– between allantois contents, kidney,
30% of herd and the amnion liver and urine
affected, +/–
haematuria
IBR (virus) 25–50% > 6 months Autolysed Autolysed
affected

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