postmortem in poultry necropsy https://www.udemy.com/course/poultry-farming-viral-diseases-threaten-poultry-industry/?referralCode=EAFBDC5B623DADAAFD25

1. Conducting a necropsy

2. The necropsy is essential to
quickly observe the internal lesions,
establish a differential diagnosis and
decide on the course of action

3. the challenge of a good poultry
diagnosis is to
identify the most significant flock
problem(s) rather than
focusing on individual bird
pathologies. For large poultry
flocks, approximately five
dead birds as well as five
individuals showing clinical signs
should be selected for
necropsy. Euthanasia of the sick
birds should be performed
rapidly and humanely in
accordance to ethical standards

4. For further analysis and
confirmation
of your tentative/preliminary
diagnosis
birds or samples
should be sent to an animal
diagnostic laboratory.

5. Taking samples
Some samples can be taken when
birds are alive (e.g. blood samples,
tracheal swabs...) or at postmortem.
Blood
samples are usually collected for
serology. Paired sera
taken two weeks apart will be
desired if seroconversion to
some disease is expected. In adult
birds, collecting eggs
will also serve this purpose since
antibody titers can be
measured from the yolk.

6. Blood can easily be sampled
from the brachial vein in
most birds, such as young and
mature chickens, while
the tibiotarsal vein is a good
option for turkeys and ducks
Dampening the
skin with 70% alcohol will help to
better define the vein.

7. In most birds, a ½ to 1 inch, 21 to
22 ga needle (depending
on the size of the bird), with a 5 ml
syringe, will suffice.

8. Do not use a vacutainer for avian
blood collection as the vein
will simply collapse, but apply a
gentle steady negative pressure on
the syringe plunger to withdraw
blood. Avian blood will easily
coagulate during sampling.

9. For most serological analysis, a 2
ml blood sample will be
adequate. Blood should be
collected aseptically in a vial
and laid horizontally until it clots.
Placing vials in warm water right
after

10. collection will hasten the clotting,
while refrigeration will hinder the
coagulation process. Sera can
then be transferred in vials, put on
ice and shipped to the
lab. Never freeze sera if
agglutination tests are planned
since this might cause false positive
reactions.

11. Upon performing the necropsy,
numerous tissues and
organs can be sampled depending
on observed lesions. If
bacterial cultures or viral samples
are needed, they should
be collected as aseptically as
possible using sterile scalpel
blade (e.g. to collect joint/sinus
exudates). Shipping whole
or parts of organs to the laboratory
is also an option.

12. Tissues for histopathologic examination
can be immersed
into 10% formalin (or other fixative),
immediately after
death. Specimens should be small for a
quick fixative
penetration and preserved in ten times
their own volume.
Ensure the container is tight and leak free
for shipping
purposes. (Alternative shipping: remove
specimens
from the jar and ship in a Ziploc bag with
a paper towel
dampened in formalin to keep the tissue
moist, but that will
not crack or leak or spill in transit due to
the sensitivity of
shippers. Label the bags, of course).

13. Feed samples should
be collected from the feeders if a
problem with an ingredient, drug
level, etc... is suspected,
when there is feed refusal, or
whenever mortality, drop
in egg production, poor growth
performances, are
unexplained.

14. Waterfrom the wells and
from the end of the water line
should be analyzed at least once a
year to determine
microbiological and biochemical
characteristics. Water pH
and chlorine levels can be
estimated with specific color
strips.

15. If ventilationis suboptimal
during the visit, ammonia,
CO2, relative humidity can easily
be measured with
the appropriate instruments. Barn
temperature can be
measured and comfort zones can be
established with an
infra-red thermometer. Many barns
are also equipped with
computer controlled ventilation systems
monitoring and
logging minimal, maximal and
mean barn temperatures as
well as relative humidity.

16. The visit report
The visit report should include farm/barn
identification,
description of the problem
(who, what, when, where, how...),
clinical observations, necropsy
findings, conclusions and
recommendations based on
available facts. A tentative
diagnosis can be offered pending further
laboratory test
results. Confirmation should be given as
soon as possible
via a phone call to the flock
owner/manager or technician.