Necropsies, the equivalent of human autopsies
In every murder mystery, there is a scene where the coroner interprets markings, bruises, and injuries on the dead body to estimate a time and cause of death.
What most people don’t know is that a similar process occurs in veterinary medicine. Necropsies, the equivalent of human autopsies, are performed by both primary care veterinarians and specialized veterinary pathologists to determine an animal’s cause of death.
Dr. Ian Sprandel is a veterinarian pursuing specialization in pathology at the University of Illinois Veterinary Diagnostic Laboratory in Urbana. As a pathologist, he performs necropsies on animal patients from the college’s Veterinary Teaching Hospital as well as on animals sent from clinics, farms, and zoos in the surrounding area.
“The purpose of a necropsy is to determine a cause of death,” Dr. Sprandel explains. “Sometimes this is a direct cause of death and sometimes it’s a morbidity, which means it led the animal to be euthanized.”
A major challenge for pathologists is determining if changes in the body are caused by the inciting disease, or if they are simply incidental. Older animals will have age-related changes, such as cysts in the kidney or loss of muscle mass. Some changes are post-mortem changes, which means they occur naturally in a deceased animal.
Dr. Sprandel walks us through a typical necropsy.
“First, we perform an external exam, similar to a physical exam done by a veterinarian at a clinic,” he says. “Next, we systematically open up the body and examine all the organs while they are still in the body cavity. This helps us to see displaced or twisted organs. Then we collect tissue samples of every major organ.”
These tissue samples are saved in case further tests are needed or the pathologist decides to look at the tissue under a microscope. Tests are frequently done based on certain lesions or injuries the pathologist sees in the body.
“After collecting the samples, we remove each organ, examine the surface, and incise it at regular intervals to look for internal lesions. Once again, samples are collected and preserved, in case they are needed later,” says Dr. Sprandel.
These samples need to be stored in a special solution to prevent tissue deterioration, which could alter or thwart a diagnosis.
“We are able to successfully reach a diagnosis about 75 percent of the time, based on examining the body, looking at tissue through a microscope, and performing more specific tests based on our list of possible causes of death,” he reports. “However, that doesn’t mean the other 25 percent of cases are a complete failure.”
Even if a definitive cause of death isn’t reached, pathologists are able to rule out many possible causes. In addition, there are some diseases or fatalities that don’t cause any injuries to the body at all, like certain heart problems or types of epilepsy.
There are also lesions the doctors see on a regular basis. “In young animals, we see a lot of congenital abnormalities, which makes sense because if an animal is born with a defect, it won’t live very long. Old animals typically have neoplasia or age-related disorders, such as kidney failure in cats,” Dr. Sprandel says.
Getting a necropsy done is not expensive, considering all the expert analysis and testing that is included. Prices usually range between $100 and $200. Pet owners can receive the remains back for burial or can have the body cremated after completion of the necropsy.
When asked if necropsies are beneficial, Dr. Sprandel responds with a definite yes.
“In farm (production) animals, finding a cause of death is important for herd health—you want to keep the rest of the animals on the farm healthy.”
For small animal owners, determining a cause of death can help with peace of mind. “Necropsy can provide answers and closure for the sudden death of a pet, or it can help assure owners that it was, in fact, time to euthanize a pet with failing health.”
Necropsies are also very important for monitoring diseases in a community. If pathologists observe an increase of a certain bacteria or virus in the caseload, they can alert primary care veterinarians and increase preventive treatment for these conditions in the population. In that way, necropsy of a pet that succumbed to an infectious disease can potentially save future pets from the same fate.
A biopsy is when a sample is taken from a living animal for diagnostic evaluation. This usually refers to tissue samples which are taken from abnormal areas or growths. These samples are placed in special solutions to preserve them, such as formalin. The sample is then sent to a pathologist who can then section the samples on a special instrument that slices them super thin and evaluated in a process called histopathology. The sectioned samples may be specially stained and are evaluated microscopically so that a diagnosis can be made.
The necropsy should be performed as soon as possible, otherwise the pet should be refrigerated, as autolysis (tissue breakdown) can occur very quickly. The animal should never be frozen as artifactual tissue changes will ensue, making histologic interpretation difficult. If the pet cannot be brought in for a long period before a necropsy can be performed then it could be frozen. Freezing/thawing will make gross observations difficult and severely hamper histopathologic analysis as the ice crystals damage the tissues. However, viral or bacterial isolations and some toxicologic analyses can be conducted on frozen samples.
A detailed description of the necropsy technique is beyond the scope of our discussion, however, a few important points should be made. Before performing the actual dissection, the animal should be carefully evaluated by the veterinarian for overall condition and checked for any obvious external abnormalities such as wounds, swellings, discharges, and staining. A systematic approach should be followed when performing the necropsy.
Performing necropsies is an important part of veterinary medicine. Frequently veterinarians are presented with animals that had “died suddenly” at home. Pets can be very sensitive to airborne toxins, poisons or other potential household hazards so they can sometimes die suddenly at home. However, some pets tend to hide their illnesses, so quite often they are near death or dead by the time an owner notices that there is a disease condition. Necropsies can help determine the cause of these ‘mysterious’ deaths. It is of utmost importance to have a necropsy performed if the cause of death is uncertain or may have a possible infectious origin, especially if there are other animals (or people) who may have had contact with the deceased pet. In addition, the risk always exists for zoonotic diseases (diseases of animals that can be transmitted to people), which should be ruled out to protect your family.
Many times clients are hesitant to have a necropsy performed because they would like to take the pet home for burial or do not want the pet dissected. These fears can be alleviated by the option of a “cosmetic” necropsy. In a “cosmetic” necropsy an opening is made just large enough to adequately evaluate the internal organs and obtain whatever samples are necessary. The incision is then sutured or tissue glued so that minimal disturbance is evident. However, depending upon the circumstances a complete and thorough necropsy is preferred.
How long after death can a necropsy be performed?
Autolysis (tissue breakdown) begins as soon as death occurs, and this can significantly impact the results of a necropsy. Therefore, the sooner a necropsy can be performed, the better. “Rabbit necropsies should be done, if at all possible, no later than six hours after death,” says Dr.
You would not believe what we found inside this dead dog! Necropsy. Dr Carter Vet. #cancer #ovaries
Have you ever had cause to have your veterinarian undertake a necropsy? Has your veterinarian ever offered one? Maybe you have but you’re still not quite sure what the word “necropsy” means.
“Autopsies” are for humans as “necropsies” are for animals. It’s a procedure we undertake by way of gaining more information on your pet’s disease … after he’s dead, when we no longer have to tread so delicately.
Perhaps you’re wondering why you would ever want one of these gruesome-sounding procedures for your pet, or why your veterinarian would ever think to ask permission for such a horrific thing.
If you are, you should know that you’re not alone. Religious beliefs and respect for the dead being what they are, there are plenty of legitimate reasons to decline to participate in having your pet opened up post mortem. Never fear, your wishes in this regard will always be respected in veterinary medicine.
And yet there remain many compelling reasons to perform necropsies. Here are the primary reasons why:
But it’s not always easy to know when your pet needs a necropsy. Here are some obvious examples:
And then there are the hows to tackle. This isn’t always so easy. Most of the time I find myself asking for permission from the owners of the deceased. This is a delicate area to tread, and so you know, not a moneymaking proposition. I simply want to investigate the damages for my own personal medical knowledge — not for a fee.
But from an owner’s point of view, these are the issues you need to know should you specifically choose to have a necropsy performed:
Just remember, necropsies are important. If your veterinarian asks your permission, we’ll understand if you refuse. But also know that we have much more on our minds in these cases than the desecration of your pet’s remains. We may not always ask in the most diplomatic way possible, but please be aware, we do have the betterment of animal medicine in mind when we do so.
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