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Necropsy is a Valuable Tool in Disease Management
By Clay Wright, Noble Foundation


Cattle
producers vaccinate cattle against common viral and bacterial diseases, control
parasites, try to create a safe environment, and regularly monitor general herd
health status. Sooner or later, though, all producers will experience sickness
and death loss in their operations.
The degree of concern about the sickness or
death of an animal is influenced by the producer's experience, the circumstances
surrounding the incident, and the number of cattle affected. Every event,
however, should be questioned, evaluated and resolved to the satisfaction of the
producer. It is important to know what you are dealing with so an appropriate
response can be initiated.
When an animal gets sick, we generally treat it
based on the symptom or group of symptoms exhibited, using our own knowledge and
experience and following routine treatment regimens assigned by a qualified
veterinarian. Treatment may be changed until a sick animal shows adequate
response to the product(s) used.
There are, however, other tools that can help
to identify the specific cause of disease: nasal swabs, blood samples, manure
samples, etc. Knowing what specific organisms are present and which treatments
are most effective can decrease response time and reduce the severity and spread
of a disease.
The same is true when an animal dies. In some
instances, the cause of death is obvious; in others, it is reasonably apparent
and at times, there is no clear explanation. Regardless, the most useful and
inclusive diagnostic tool available to us is a necropsy — a post-mortem
examination performed by an experienced veterinarian. The objective is an
accurate diagnosis of the cause of death.
Although we usually think of a necropsy as an
internal examination of the dead animal, the evaluation/diagnosis process begins
with gathering all relevant information surrounding the death: climate, animal
stress levels, nutrition status, pasture composition and condition, past
immunization regimen, possible exposure to disease, number of cattle affected,
obvious symptoms, etc.
Then, after a thorough external inspection of
the dead animal, the veterinarian will conduct the systematic internal
examination. When indicated, tissue and fluid samples will be taken and
submitted to a diagnostic laboratory for further specific analysis.
When a necropsy is performed in a timely
manner, a dead animal can often reveal more than a live, sick one. It should be
done as soon as possible after death, since tissue changes begin to occur almost
immediately. The window of opportunity will depend primarily on air temperature
and the nature of the illness itself.
Even when intensive precautionary animal health
measures are taken, we can only hope to minimize the occurrence of disease.
Containment and low treatment costs depend on early, accurate diagnosis of the
problem. A timely necropsy by a qualified veterinarian is one of the most
valuable tools available, and should be a routine practice in every operation.
A final word — technically, a necropsy is not
complete until the carcass is disposed of. Each state has published rules
addressing proper disposal of dead livestock. Burial-to-specification or burning
are the most common approved means of disposal. Be familiar with, and follow
these guidelines to ensure you are in compliance with the law and that the dead
animal is not a continued source of infection to other cattle. |