Practical Pointers When Investigating Abortions in Cattle and Sheep

Abortion investigations in cattle and sheep can be frustrating, time-pressured, and often unrewarding if the wrong samples are collected — or none at all. When whole foetuses and placentas cannot be submitted, targeted sampling can still provide strong diagnostic value. Below is a practical guide to help maximise diagnostic yield while managing client expectations and lab workflow.

Core Samples to Collect (When Full Submission Isn't Possible)

Whether you’re dealing with a Holstein or a Hebridean, three samples are considered essential when whole foetus and placenta submission isn’t feasible:

Priority samples:

• Foetal stomach contents
• Foetal fluids
• Placenta.

These samples allow routine screening for the most common infectious causes of abortion in both cattle and sheep.

Additional Samples to Consider

Depending on the clinical history and post-mortem findings, consider collecting additional tissues — especially if routine testing does not yield a diagnosis.

Useful additional tissues:

• Spleen
• Thyroid
• Umbilicus
• Brain
• Fixed tissues (if possible):
  
  • Placenta
  • Liver
  • Lung
  • Heart
  • Brain.

These can either be submitted immediately or stored at the practice pending results.

Important: Do not post large volumes of formalin.

If in doubt about sampling choices, contact the diagnostic lab directly. A detailed sampling guide is also available.

Mummified Foetuses: Set Expectations Early

Diagnostic success rates from mummified foetuses are very low in both cattle and sheep.

• Advise clients accordingly before submission
• Testing is often not cost-effective
• Fresh, non-mummified foetal material provides far greater diagnostic value.

Managing expectations at the outset helps avoid disappointment and unnecessary expense.

Histopathology: Species Differences Matter

Histopathology can be helpful — but its value differs between species.

Cattle

• Fixed tissue histopathology is often worthwhile
• Can provide useful diagnostic direction.
  

Sheep

• Frequently unrewarding, particularly when:
  
  • Foetuses are autolysed
  • Placenta is unavailable.

In ovine abortion outbreaks, faster and more useful results are often obtained by submitting material from additional affected ewes rather than relying on histopathology alone.

Clinical History Improves Diagnostic Yield

History and presentation should guide testing decisions.

Include as much relevant information as possible on submission forms:

• Herd/flock history
• Stage of gestation
• Number affected
• Vaccination status
• Clinical signs
• Biosecurity risks.

Labs are significantly more likely to recommend or automatically run additional targeted tests when good clinical history is provided.

Dam Blood Samples: When and Why to Collect

If the dam is available, collect and store a blood sample pending foetal results.

Key points:

• Positive antibody results indicate exposure — not timing
• Seropositivity may reflect:
  
  • Historic infection
  • Vaccination
• Paired serology is generally not useful in abortion investigations.

Exception:

• Salmonella dublin in cattle — paired samples may be informative.

Neospora caution:

• False positives can occur in foetal fluid antibody tests
• Follow-up dam serology ± heart/brain histopathology improves interpretation.

 

Abortion Sampling Kits

We can supply pre-prepared bovine and ovine abortion kits which can streamline on-farm investigations. Keeping kits in stock reduces delays and improves sample quality.

If you would like kits supplied to your practice email VSEnquiries@sruc.ac.uk request them in advance so they are available when needed.

Posted by SRUC Veterinary Services on 30/01/2026