Awesome-veterinary

Post mortem examination of the skull

To gain access to the brain in the head we need to remove the head.
It requires the disarticulation of the atlantooccipital joint.
Locate atlanto-occipital joint by turning the head up and down.
Cut the soft tissue ventral to the joint. Continue the dissection until the exposure of the ventral spinal canal.
Turn the head up & down again to identify the exact location of the atlantooccipital joint.
Enter the knife between the atlas & occipital condyles and cut the attachments.
Extend the cut laterally along both sides of the adjacent tissues.
Continue the cut until the head is fully detached.

Procedure

Medial & ventral to the occipital condyles,retro-pharyngeal lymph nodes are present which are a good source for microbiology testing. Remove the nodes, dissect & keep them for the tests.

Procedure

Insert the knife through the skin to the dorsal upper eyelid and dissect it circularly.
Remove the peri-ocular tissue.
Place the entire globe in formalin for histological examination.

Procedure

To remove the brain, the skin on the head must first be reflected. With the sharp edge of the knife facing up, cut the skin at the midline of the head.
Extend the cut laterally on both sides exposing the underlying skull.
Make two cuts medial to each occipital condyle.
Extend these cuts rostrally to join with a third cut made just caudal to the two supra-orbital processes.
Using the ax & hack saw, open the skull along with these planes/cuts.
Use the knife to cut away any dura adhering the brain to the bone.
To remove the brain cranial nerves are cut off by gently sliding the knife under and around the brain.
Lift the brain out of the skull & inspect the surface for abnormalities.

Sample collection

Specific sampling

Remove a 1 cm cross-section of the cerebellum as a sample for a rabies test. Place the sample in a covered Petri dish.
To collect the BSE sample, remove a 2 cm cross-section of apex & place it in a large test tube with a screw arm lid.
Take samples from the cerebellum & cerebral cortex for microbiology & toxicology tests.
Place one half of the sample in a plastic bag for virology testing.
Place the remaining portions of the brain in formalin & submit for the histology.
Bisect the brain into two smaller halves & place them in two separate formalin jars.

Procedure

Cut across the snout at the level of first cheek tooth
Give another cut anterior to the first cut
Alternatively, turn the anterior piece of the snout and cut it along the ventral midline to expose the turbinates
Examine the exposed surface

Procedure

In Cattle, Remove the muscles from the right lateral side of the vertebral column
In the horse, do it on the left side
Remove the exposed transverse processes of the vertebral column until the spinal cord exposed
Beginning with the anterior end of the spinal cord
Remove the entire spinal cord.