6-15-05

Dealing with Death in Camelids:
Necropsy or Post-Mortem Exam

Tracy Miesner, DVM
David E Anderson, DVM, MS, DACVS
International Camelid Institute
www.icinfo.org


The loss of an animal that you have been caring for is never an easy pill to
swallow, especially if there was little or no warning of the potential loss of life.  
Death that occurs suddenly and without warning often leaves care takers
with many questions and few clues that would lead to an explanation.  The
International Camelid Institute, along with many other veterinarians, has often
been asked to explain sudden death.  This is typically when the discussion of
post-mortem exam arises.  Discussing the disposition of a loved animal's
remains is difficult at such an emotional time, so it seems a pre-emptive
discussion of the details and importance is prudent. Veterinarians can
provide no reliable information on the cause of an animal's death if no
post-mortem examination is done. These exams are preferably done by a
pathologist at a diagnostic lab, but on-farm examinations can be informative.
Veterinarians are frustrated when we are asked to explain why a farm has
lost 4 llamas or alpacas over the past year, but no diagnostic tests or
ost-mortem examinations have been performed on any of them. 

Post-mortem literally means after death.  So, a post-mortem exam, or
sometimes called necropsy, is the examination of an animal's remains after
they have died. Veterinarians do not use the term "autopsy" because that
refers specifically to examination of humans after death.  The timing of
these exams is critical to the ability of a pathologist or veterinarian to
interpret their findings.  Decomposition starts immediately after death and
the rate is based on the climate that the body has been stored in: heat and
humidity accelerate the decomposition process.  When an animal dies or a
fetus is aborted and post-mortem exam has to be delayed, refrigeration of
the body and fetal membranes is required.  Freezing significantly alters
tissues and should be avoided.  Not many people have access to a large
enough refrigerator for an adult camelid, so call a veterinarian immediately
if you are considering a necropsy exam on your animal.  If you are
fortunate, you have access to a veterinary school or state diagnostic
laboratory.  That can be a particularly attractive option for those that
have the unfortunate responsibility of dealing with the remains of a
departed animal.

Why is it necessary to thoroughly exam the remains of an animal that died
for unknown reasons?  Why can't my vet just tell me what happened?  The
fact is that many of the "symptoms" that are described at the time of death,
such as seizures, do not necessarily have anything to do with the cause of death.

Pre-death seizures can simply be what we call agonal signs; things the body
does as a result of dying.  The lists of diseases and conditions that can
cause sudden, unexplained death in an apparently healthy animal are
extremely lengthy.  Sometimes you get lucky and find evidence on external
exam, but often internal and microscopic examination is required in nearly
all cases.  When there are other animals on the farm, many people want to
try to make sure that their other animals are not at risk BEFORE others are
affected, and nobody can assess the risk to the other animals when they
don't know why the first one died.  Additionally, attempts to determine
cause of abortion or pregnancy loss also must be similarly investigated. One
of the comments we hear is, "they can never tell me the cause". Remember, a
negative finding on necropsy is just as significant as a positive finding.
It is frustrating to know the cause of death in that one animal, but a
"negative" necropsy exam has tremendous benefit in trying to determine
rule-out diagnoses, especially for future problem cases.
What about plant toxicity or intentional poisoning?  In this situation, the
investigation includes a list of suspected culprits and a toxicology
analysis.  The contents of the stomach are required in these situations, but
in the situation where long term, chronic ingestion of toxic plants or
poisons are involved then other samples will need to be taken and analyzed.

In veterinary medicine, there is no such thing as a "tox screen". Testing
blindly for any possible toxin would cost tens-of-thousands of dollars. You
have to know what you want to test for and you have to ask for it
specifically.  Thus, it is crucial to discuss the case with a specialist in
animal toxicology to determine a list of "reasonable" guesses. Some state
diagnostic labs might make some recommendations based on there previous
experiences with toxic plants and poisonings in your area during a given
season, but some will not.

Sometimes post-mortem exam reveals a long standing chronic problem that
went undetected.  Some animals are particularly stoic and don't show signs of
illness for fear of appearing weak to predators.  In some instances, illness
that progresses slowly over time will allow an animal to "compensate" and no
illness will be detected by caregivers.  As an example, anemia or too few
red blood cells can get extremely severe if it occurs over a long period of
time, such as is the case in severe parasitism or other chronic illnesses
that affect red blood cell production.  Normally, an animal's blood will be
around 30% red cells, we have seen animals that are still functional with
red cell counts as low as 4%.  If you quickly removed that much blood from
an animal, they would die, but if it happens slowly over time, then you
might not see any evidence until the animal is critical.  In a situation
where parasites are to blame, then the other animals on the farm might be at
risk and this would be a situation worth investigating.

Of course, there are always situations were something catastrophic, but
isolated occurs to an animal that was either unpreventable or untreatable.
For example, lightening strikes or other electrocutions, rupture of major
blood vessels due to aneurysms or other anatomical anomalies, severe head
traumas, and other sorts of things that would be unlikely to afflict others
in the herd.  In these situations it is worth the piece of mind to know that
the others are not likely at risk and that you couldn't have prevented the
outcome.

A necropsy is an opportunity to look at your nutrition. This may give
insight as to the cause of death, but may also give you an idea of how your
farm is doing nutritionally. We recommend that you have a piece of liver,
collected within 12 hours of death, frozen and shipped to a nutrition
laboratory (e.g. Michigan State University Diagnostic Laboratory) for trace
mineral analysis. In sick animals, this is not useful for looking at herd
situations, but is useful to look for possible causes of death. In an acute
death such as trauma, liver is very insightful as to the adequacy of farm
nutrition.

Some post-mortem exams or necropsies do not reveal the cause of death.  This
is frustrating for both the owner or caregiver and the veterinarian doing
the exam.  We all prefer to have a solid explanation, it makes us feel more
in control. However, we can not emphasize enough the necessity of
post-mortem exam on every death and every abortion. If you look you might
not find anything. If you do not look, it is predetermined that you will
learn nothing. Not to try is inexcusable; to try and fail is a part of life.
We recommend that every death, every stillborn, every abortion should be
examined by a pathologist every time.

This leads to the hard part, making the decision to have an exam done on the
body of a beloved animal.  It is hard when you think of it as a desecration
of the body.  The fact of the matter is that it is invasive, and it is
extremely difficult, if not impossible, to do it "cosmetically" AND
thoroughly.  And, the likelihood of a diagnosis often is determined by the
skill and expertise of the individual performing the exam.  Most diagnostic
labs can offer assistance to veterinarians in the field to secure adequate
and appropriate samples for shipping to the laboratory.  This can be a good
alternative for those owners that wish to bury the remains of their animal
on the farm. 

Ultimately, when one can force themselves to be objective, a
post-mortem exam is the most practical and desirable option for trying to
determine the cause of an unknown or unexpected death or loss of fetus. We
recommend that every death, every stillborn, every abortion should be
examined by a pathologist every time.

Return to     Health             RMLA Home