Key Insights
  • Equine necropsy is the post-mortem examination of a horse to determine cause of death
  • It is especially important in cases of infectious disease, toxins, or herd health concerns
  • All organ systems are examined and tissue samples may be submitted for further testing
  • Most necropsies are performed by veterinary specialists in diagnostic labs, though some can be done on farm
  • Necropsy reports are typically available within 48 hours, with additional testing taking weeks
  • Only licensed veterinarians can make post-mortem diagnoses of horses; non-professional dissections may not have accurate findings

Necropsy, also known as an autopsy or post-mortem examination, is an important diagnostic tool in equine veterinary medicine. When a horse dies unexpectedly or under unclear circumstances, performing a necropsy can provide critical insights into the cause of death.

Necropsy is particularly valuable in cases involving infectious disease, toxic exposure, or herd health concerns, where understanding the source of the problem can protect other animals from harm. A necropsy can also offer closure by answering lingering questions, and in some situations, it may have significant legal or insurance implications.

The necropsy process involves a thorough external and internal examination of the horse’s body, usually performed by a veterinary pathologist or experienced veterinarian. Tissues are collected and analyzed histologically, microbiologically, or toxicologically depending on the suspected cause of death. Findings are compiled into a detailed report that can guide future medical decisions and inform disease control strategies.

Read on to learn more about the importance of necropsy in equine medicine, when it should be considered, what to expect during the process, and how the results can benefit both individual horse owners and the broader equine community.

Necropsy in Equine Medicine

Necropsy, also called autopsy or post-mortem examination, is the process of medically examining a body after death. [1] This procedure allows veterinarians to identify cause of death or diagnose disease conditions that were undiagnosable during life. Necropsy can also provide owners closure by giving them a deeper understanding of why their horse’s condition led to death or euthanasia. [1]

During a necropsy, the veterinarian systematically examines all of the horse’s body systems. In some cases, they collect tissue samples to submit for histopathology, examination of tissues under the microscope to identify disease. They may also collect samples to submit for bacterial culture, virology, fungal testing, toxin testing, and more. These tests increase the likelihood of reaching a final diagnosis.

Necropsies can either be performed on farm or at a diagnostic laboratory. [2] On-farm necropsies are typically performed by the horse’s primary veterinarian, while diagnostic laboratory necropsies are performed by veterinary pathologists, veterinarians who have additional specialized training in necropsy and diagnosis.

Many veterinarians prefer to avoid performing necropsies and require their clients to submit the horse to a laboratory for examination if a post-mortem review is warranted. Additionally, insurance companies or government bodies may require laboratory examination in some cases. [2] Work with your veterinarian to determine where the necropsy should take place based on your individual situation.

Clinical Use

The major role of necropsy is diagnosing cause of death when a horse died for unknown reasons. Understanding why animals die has important implications for herd management, particularly in the case of infectious or toxic diseases.

By identifying cause of death, changes can be implemented to treat or manage the remainder of the herd, preventing further illness or death. Some diseases, such as rabies, may also affect humans, so a timely and accurate diagnosis is critical to prevent human infection.

In some cases, government bodies require necropsy of horses suspected of having certain diseases. This allows for rapid diagnosis and the implementation of control measures to prevent disease spread.

Diseases that may require a necropsy in some jurisdictions include: [3][4]

However, necropsy can serve many other purposes besides disease identification and control.

Other reasons to submit a horse for necropsy include: [1]

  • Verifying cause of death or the severity of a disease
  • Closure for the owners
  • Requirement by insurance companies
  • Research purposes, including writing case reports on unusual conditions
  • Education of veterinary students or other veterinary practitioners

Equipment

Whether performed on-farm or in a diagnostic laboratory, the equipment necessary for an equine necropsy is similar. Tools that veterinarians use include: [2]

  • Knives
  • Rib cutters
  • Scissors
  • Forceps
  • Scalpels
  • Handsaws
  • Personal protective equipment, such as gloves, goggles, aprons, etc.

If the veterinarian elects to collect tissue samples, they use sterile containers to place the tissues in. Depending on the type of testing they wish to perform, the tissues may be fixed in formalin or frozen.

Necropsies should be performed in areas that are easily disinfected in case the veterinarian identifies an infectious agent. [5] Concrete flooring is ideal and preferred over tarps, grass, or dirt. Other considerations include the accessibility of water to wash away debris, blood, and small pieces of tissue.

Procedure

The following section contains a detailed description of horse dissection, which may be sensitive for some readers.

 

The veterinarian performing the necropsy must carefully inspect all aspects of the horse’s body to ensure an accurate diagnosis. This process involves dissection, cutting of tissues, to allow access to the horse’s internal organs.

To begin, the veterinarian examines the exterior of the body to identify any problems. The skin is thoroughly assessed, looking for signs of disease, scrapes, burns, or other abrasions. [5]

The veterinarian also notes any distinguishing markings, scars, or brands that can identify the horse for future reference. [5] This is particularly important for cases of a legal nature or for insurance companies to confirm the correct identity of the horse. [5]

The veterinarian then opens the body into “display phase“, where the thoracic and abdominal organs are visible. [6] This involves removing the front and hind limb on one side of the horse’s body and cutting away the abdominal muscles and ribcage.

Once in display phase, the veterinarian can examine for any changes in the organs and their position. This is particularly important for suspected colic cases, as changes in the position of the intestinal organs are most easily identified during this step. [2] Many veterinarians also collect tissue samples during this stage, as the organs are not yet contaminated by the external environment.

After observing the organs in display phase, the veterinarian proceeds to remove each organ system for further examination. Throughout their examination, the veterinarian looks for any abnormalities such as signs of inflammation, tumors, or tissue damage.

The Pluck

The “pluck” refers to the tongue, trachea, esophagus, thyroid, heart, and lungs after they are removed in one large section. The veterinarian examines each organ individually, often cutting it into sections to observe all aspects of the tissue.

Specific conditions that the veterinarian may identify when assessing the pluck include: [7]

The Gastrointestinal Tract

The veterinarian examines the entire gastrointestinal tract, usually by spreading the intestines out on the floor. This allows for careful examination of each section and identification of any issues.

Conditions the veterinarian may identify at this stage of the necropsy include: [7]

The Urogenital Tract

This segment includes the horse’s kidneys, adrenal glands, bladder, and urethra. The veterinarian cuts each kidney in half to examine the parenchyma (inner tissue) for abnormalities.

Conditions the veterinarian may identify from this sample include: [7]

The Liver & Spleen

The liver is a vitally important organ as it has roles in detoxification, metabolism, blood clotting, and more. Similarly, the spleen has important roles in infection control and removal of dead cells from the bloodstream. Thorough inspection of these organs involves cutting numerous sections of tissue to inspect the parenchyma.

Liver and splenic conditions the veterinarian may identify include: [7]

The Brain

After removal from the skull, the brain is typically submitted to a diagnostic laboratory without further dissection. This is because many of the diseases affecting the horse’s brain and nervous system do not produce gross lesions (lesions visible by observing the organ).

To diagnose these conditions, additional testing such as bacteriology, virology, or histopathology is necessary.

The Musculoskeletal System

Due to their large size, a complete examination of the musculoskeletal system is very challenging in horses. Most veterinarians do not perform a thorough musculoskeletal examination unless the horse’s history suggests there may be a problem within this body system.

Examining this body system may involve a combination of careful dissection, boiling bones to remove tissue, or cutting limbs in half for closer inspection.

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Interpreting Results

The veterinarian performing the necropsy writes a necropsy report at the conclusion of their evaluation. This report summarizes their observations and suggests potential diagnoses that explain their findings. Any lesions (abnormalities) are described in this report, including their location, shape, color, size, and severity. [2]

Depending on the suspected conditions, additional testing may be necessary to make a diagnosis. Tissue samples collected during the necropsy are submitted to a diagnostic laboratory for further processing.

Additional tests requested by the veterinarian may include: [2]

  • Viral testing
  • Bacterial culture
  • Fungal culture
  • Serology
  • Toxin testing
  • Histopathology
  • Genetic testing

The diagnostic laboratory writes a report summarizing their findings, often including their interpretation of the results. The veterinarian receives this information and reports the findings to the owner.

Clean-Up & Disposal

Due to the large size of horses, having an appropriate clean-up and disposal plan is important prior to performing a necropsy. Practical considerations surrounding transport and disposal are a common reason for owners to decline necropsy after a horse’s death. [1]

For on-farm necropsy, it is crucial to dispose of the body safely and legally after the procedure. For example, the body can pose a biosecurity risk if the horse died of an infectious disease. [2]

Horses euthanized using barbiturate euthanasia also pose an environmental risk, as the barbiturate may poison scavenging animals or spread into ground water. [2]

Common disposal methods for on-farm necropsy include: [2]

  • Transport to a landfill or composting location
  • Burial in a deep hole, depending on local bylaws
  • Leaving the body for scavengers in cases of sudden death or non-barbiturate euthanasia
  • Transport to a cremation facility

Since the internal organs are removed during the procedure, they often require separate handling for disposal. This may involve burial, disposing of the organs in sealed barrels, or replacing the organs within the body and sewing the incision closed.

For laboratory necropsies, the remains are typically sent to a biosecure rendering facility for disposal.

In some areas, cremation may be available for horse owners. Typical equine cremation involves cremating the “head, heart, and hooves” to produce a manageable amount of ashes for the owner. Some areas may be able to cremate the entire horse.

Frequently Asked Questions

Here are some frequently asked questions about equine necropsy:

Summary

Necropsy involves careful examination of a horse's internal organs to determine the cause of death or severity of disease.

  • Necropsy is particularly important in cases involving infectious disease or toxins, where other horses may be at risk of illness or death
  • Necropsy can also offer owners closure and help them understand their animal's condition better
  • All organ systems are carefully examined during the necropsy process
  • Necropsies can be performed on farm in some cases, although most are performed in a diagnostic laboratory
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References

  1. Inglis. Z. E. et al., Owner Perceptions and Experiences with Equine Necropsy. Journal of Equine Veterinary Science. 2024.
  2. Frank. C. et al., Field Necropsy of the Horse. Veterinary Clinics of North America: Equine Practice. 2015.
  3. Reportable Diseases: Terrestrial Animals. Canadian Food Inspection Agency. 2011.
  4. National List of Reportable Animal Diseases. US Department of Agriculture. 2025.
  5. Taylor. F. G. et al. Diagnostic Techniques in Equine Medicine (Second Edition). W.B. Saunders, Edinburgh. 2009.
  6. King. J. M. et al. The Necropsy Book: A Guide for Veterinary Students, Residents, Clinicians, Pathologists, and Biological Researchers. First University Press. 2013.
  7. Buergelt. C. D. and Del Piero. F. Color Atlas of Equine Pathology. Wiley Blackwell. 2013.