Test 2- Necropsy and lab techniques Flashcards
Necropsy / Post-mortem exam
A necropsy is a procedure, and like all procedures, there is a system to use. If you always remember the basic SYSTEM of necropsy, you will always do a thorough job, and won’t miss any key lesions.
There are 6 steps to a successful necropsy:
- Get the history
- Do an external examination
- Open the body
- Remove the organs
- Examine and sample the organs
- Write the report
We do this to determine the cause of death or the changes produced by the disease
General biosafety considerations for necropsy areas,
General biosafety considerations for necropsy areas, minimizing the potential for zoonotic infection
PERSONAL PROTECTION AND HEALTH CONCERNS
- Some animal diseases are zoonotic.
- It is important to protect the operator and any people in the vicinity from
these hazards.
Necropsy procedures pose the greatest risk of disseminating infectious agents to humans because of
Necropsy procedures pose the greatest risk of disseminating infectious agents to humans because of the large amount of tissues and body fluids exposed during dissection
Biosafety/biosecurity precautions during necropsy:
• Personal protective equipment -
• Personal protective equipment -
– Gloves
– Apron
– Boots
Persons not adequately protected will keep
Persons not adequately protected will keep a distance from the carcass
Procedural Considerations
all necropsies should “universal precautions” (all specimens should be handled and treated as though they were known to present risk of zoonotic disease!)
No eating, drinking, grooming are permitted in necropsy areas.
Rabies vaccination
Tools should be used to the extent feasible to manipulate tissues to avoid cut hazards (i.e., forceps).
Hand tools are preferred to power tools.
Carcass disposal
- Burial
- Incineration
- Composting(poultry,sheepandgoatcarcasses)
Dispose of carcasses appropriately, away from scavengers that might drag parts to other locations and inadvertently expose people.
For some diseases, such as rabies,
For some diseases, such as rabies, a vaccine is available for humans and only those people who are vaccinated should be opening the carcass and sampling tissues.
What should you wear in terms of foot wear during a necropsy?
Wear rubber boots during necropsy;sanitizethe boots by washing in disinfectant so as not to spread infectious agents beyond the site of the necropsy.
What kind of instruments are needed for a necropsy?
We use sharp instruments. Take your time, don’t rush. Be sure your knife is sharp. Most accidents with knives happen because the knife is dull.
SUSPECT ANTHRAX CASES
SUSPECT ANTHRAX CASES – DO NOT OPEN CARCASS
Collect blood from percutaneous cardiac puncture, jugular vein, or other peripheral blood vessel into both a red-top and a purple- top (EDTA) blood collection tube.
Submit sample for blood smear examination and blood culture.
Outer package must be labeled appropriately DO NOT PROCEED WITH NECROPSY!
Special Steps to examine the heart
- open right ventricle
- then left ventricle
- go into aortia

Steps to look at the brain
cut from external

Steps to look at the spinal cord

Blood Sampling
Obtain heart blood. Using a 12 ml syringe with an 18 G 1 1⁄2 in. needle, attempt to secure 3 to 10 ml of heart blood.
It may be necessary to carefully incise the left ventricle and aspirate blood from the surface. (Pleural and Peritoneal fluids may be used if blood is not available).
Express blood into a green-topped (heparinized) blood collection tube.
If possible, obtain a second 10 ml of blood and fill a red-topped blood collection tube.
If heart blood is clotted and no body cavity fluid is available, a blood clot can also be collected and placed into one of the zipper-lock tissue bags.
Urine sampling
• Obtain urine. Using another 12 ml syringe with an 18 G 1 1⁄2 in. needle, aspirate up to 10 ml of urine from the urinary bladder and put the urine into a red-top blood collection tube
Brain Sampling
Collect appropriate specimens for the state rabies laboratory before taking any other samples or dividing brain (send to state rabies lab)
Place 1”x1”portions of cerebellum, brainstem and cerebrum into each of 2 different labeled zipper lock bags for microbiology and toxicology.
The remainder of the brain needs to be placed in the largest formalin jar.
For livestock, it may be necessary to split the brain between the two
largest containers.
The best fixation will be achieved if the brain is sliced every 0.5 cm most of the way through (“bread-loafed”), leaving about 0.5-1.0 cm of tissue unsliced along the ventral portion to keep the parts together.
Skin (bovine)
Skin (bovine): 1/4 – 1/2” piece of ear skin. Place into plastic snap-top vial containing phosphate buffered saline
Adipose tissue (fat) sampling:
Adipose tissue (fat): obtain a sample 2” x 3”, if possible. Place in labeled zipper lock bag.
Liver sampling
Liver: submit a large portion (1” x 2”). Place in labeled zipper lock bag.
Kidney Sampling:
Kidney: submit a large portion (1” x 2”). Place in labeled zipper lock bag. Usually it will be trimmed in triangular shape
Eyeball sampling
Eyeball: submit intact eyeball. Place in labeled zipper lock bag.