Approach to Equine abortion

What placental membranes are exposed in these pictures?

Left = chorionic surface (inside)

Right = allantoic surface (outside)

What should be noted during the external examination of aborted foetus?

Crown-rump length

Weight

Jaundice

Meconium staining

Haemorrhage

Congenital abnormalities

Carcass condition

Carcass preservation

Describe this post mortem finding of a foetus

Moderate amount of haemorrhagic fluid in abdomen

Describe this post mortem finding of a foetus

Moderate/marked reddish clear fluid in thorax

What are 2 important viruses involved in equine abortion?

Equine Herpesvirus 1

Equine Arteritis virus (notifiable)

What foetal samples should be taken for virology PCR (5)

Thymus

Lung

Liver

Spleen

(Kidney)

4 pieces of chorioallantios

What foetal samples should be taken for bacteriology (3) and how

Liver (or heart blood if its too soft)

Lung (or stomach content via needle if cannot sear surface)

Chorioallantois - make sure cervical pole is included in swab

using charcoal swab

What foetal samples should be taken for histopathology

Liver (4 samples)

Lungs (4 samples) - multiple samples because equine herpesvirus is multifocal

Spleen

Adrenal gland (at least 1)

Kidney (both)

Thymus

Anything abnormal

What are normal findings of a foetal heart that would not be present in older animals

Patent ductus arteriosus

Foramen ovale

Name this heart pathology

Ventricular septal defect

Whats happened here?

Umbilical cord torsion and subsequent haemorrhage and oedema

What is this on the umbilical cord?

Yolk sac remnant

What is this pathology on the umbilical cord?

Amniotic nodules

What side of the placenta is this and describe the pathology

Allantioc side (outside)

Ischaemic necrosis of cervical pole

What does this placenta show?

Twin placentation

White opposing areas without vili = no attachment to uterus

What are these?

Allantioc vesicles/pouches (oedema)

Causes of ascending placentitis

Usuallty bacteria ascending from cervix

Fungal is uncommon in UK

Cause of this abortion

Fungal placentitis

Cause of this abortion

Bacterial placentitis

Cause of this abortion?

Fungal placentitis

Causative agent of this abortion? Describe the gross pathology.

Equine Viral Arteritis

Severe diffuse oedema of lung

Glisson hepatic capsule

Gastric mucousa with petechiae

Causative agent of this abortion

Equine Herpesvirus 1

Pathology associated with Equine Herpesvirus 1 in the foetus

Jaundice - markedly increased clear yellow fluid in thorax and pericardium

Thymic necrosis - turns cream/tan colour, liquefaction

Pulmonary consolidation

Multifocal hepatic necrosis

Intranuclear inclusion bodies in hepatocytes

Signs associated with Equine Herpesvirus 4 abortion

Sporadic

Excess body fluids

Sparce/absent liver and lung lesions

Spleen is best for virus isolations

Many lesions secondary to hypoxia