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Necropsy – Determining Why a Calf Died


Terminology – A necropsy is a postmortem examination to discover cause of death. An autopsy is a necropsy on humans. We request a necropsy on a dead calf.

It is difficult to know what caused a newborn calf to die hours (or days) after death. Enlisting the help of a veterinarian to identify cause(s) of death in calves soon after it occurs is always encouraged.

Sometimes the factors leading to death are easily determined upon necropsy:

  • A cow stepping on a young calf may not leave ‘a mark’ on the outside but does cause internal organ damage which may later lead to death.
  • Weak calves can be a result of limited nutritional resources for the cow during pregnancy.  A necropsy can identify lack of fat reserves in the calf. 
  • No clotted milk in the stomach indicates the calf never nursed. Either the calf didn’t figure out how to nurse or the cow has no milk. 
  • Lungs that don’t float in water indicate the calf was born dead and never breathed. 
  • A broken leg could be a spiral facture that’s shattered in pieces and results in a slow death.

Infectious diseases can also cause death. Certified pathologists and diagnosticians at the NDSU Veterinary Diagnostic Lab (VDL) perform necropsies and can run multiple tests to determine or rule out possible causes of death. With abortions, the calf and placenta are needed at the VDL to help identify infections. It might be a disease than can be prevented by vaccination or treated with antibiotics.

Viral infections require a different method of treatment. Antibiotics won’t cure a virus but may help with a resulting bacterial infection. Calf scours (diarrhea) and pneumonia can be caused by viruses and/or bacteria. Keeping records of birth dates can be a helpful tool when trying to figure out why a calf died. Age of calf at death gives direction as to ruling out causes of death. Scours at a few days of age may be bacterial, at 10 days viral, and at 21 days protozoal. These are generalities and the cause of scours should be investigated immediately to prevent other calves from becoming ill. The VDL test results will aid in the proper course of treatment for other sick calves.

 new calf napping in the North Dakota sunshine.

Healthy, new calf napping in the North Dakota sunshine.

Working with your veterinarian and the NDSU VDL can help overcome costly health issues. You can contact the NDSU Veterinary Diagnostic Laboratory at 710-231-8307 and find many helpful resources on their website

Karl Hoppe, Ph. D.
Extension Specialist – livestock systems