post mortem Flashcards
Before you begin - safety
Size and logistics
Full medical history very important
Travel history-
Exotic zoonotic diseases e.g. Brucella, Rabies
Endemic zoonotic diseases-
E.g. Leptospirosis, COVID?! (cats and mustelids), Q-fever, Salmonella
Species specific-
Non-human primates - herpes
Cattle and camelids – TB
Chemotherapy?
PPE
Sharps
Waste disposal
Allergens
Before you begin - history
History and context will form part of the reason for post mortem
Age, breed, sex will all affect
Differentials
Interpretation
Sampling
Died or euthanised?
Part of a group/herd?
External exam
Confirm and record identity-
Microchip
Tattoo
Brand
Weigh
External exam-
Overview and BCS
Crown rump length
Pelage and skin
Eyes
Feet
Faecal or urine staining
Blood
Mucous membranes
Dentition
stepts to pm
Stabilize carcass:
Forelimbs-
On the ventral surface of the carcass make a craniocaudal incision between medial scapula and lateral thoracic wall
Incise the pectoral muscles
Hindlimbs-
On the ventral surface of the carcass make a curvilinear craniocaudal incision across the inguinal area
Incise the proximomedial thigh muscles to expose the coxofemoral joint
Open the coxofemoral joint and examine
Skin the ventral aspect of the carcass
Open the abdomen- assses for fluid, asses organ position
Check for negative pressure - One person should grasp the xiphoid process and gently pull the thoracic cavity up to allow visualisation of the ventral diaphragm which should be domed cranially
Make a stab incision in both sides
Open the thoracic cavity- check for fluid
stab insision between each rib
transect ribs
remove pluck-
Tongue
Thyroid glands
Trachea
Oesophagus
Lungs
Heart
Thymus
Remove the adrenal glands
Check for gall bladder patency
Remove the spleen and liver
Remove GIT
Remove the urogenital tract
examinng organs
Kidneys-
Bisect/butterfly the kidneys along the long axis (longitudinal section)
Peel off the capsule
Trachea and lungs-
Open the entire length of the trachea and extend into the bronchi
Froth?
Bacteriology of the lungs if concerned
Breadslice the lungs
Liver and spleen-
Breadslice
Heart-
Open following the route of de- oxygenated blood
Sampling in small animals
Bacteriology versus virology
Cautery of the tissue surface for bacteriology prior to inserting charcoal swab
Lung at edge of area of pneumonia
Bacteraemia? - liver, right ventricle
Fixed versus fresh tissue:
Fixed-
heart, lung, kidney, liver, spleen, GI, brain (muscle, thymus, thyroid, adrenals)
Thinsamples for formalin penetrance
Fresh-
liver and kidney
10g
Fluids?-
Faeces?
How useful is general bacterial culture?
Urine?- not particullary usefull, can test for antifreeze
Can look for ethylene glycol crystals PM
Blood?- no h and b, can test for fpt
Cannot perform biochem and haem reliably once dead
Large animal differences - positioning
Small sheep/lambs/calves may be done as per small animals
GIT- Frequently more gas distended stomach(s)/large intestine
Overall idea and process the same but review different anatomy
Large sheep generally done in lateral recumbence with one forelimb completely removed
Generally, only one side of the thorax will beopened but cutting at the top and the bottom of the ribs on one side
Similarly, cows and horses may be done in lateral recumbence in a trolley (most PM tables only go up to 350kg)
Or, very large animals may be done hanging from a hind leg
Hanging may require removing the GIT before the pluck
samples in large animal pm
PM Blood in plain tube
ocular fluid in plain tube
faecal/ caecal ample
fresh samples- liver, kidney, spleen, brain (cerebral cortex), small intestinal contents
swabs for culture- visible lesions
histopathology- 1cm of tissue into formalin execpt brain and eyes which should be taken whole- heat, lung, liver, gall bladder, spleen, kidney, small intestine, large intestine, uterus, urinary bladder, brain, lymph nodes, thymus, skeletal muscle
samples to take from ovine abortion
fresh- placenta (at least two coteladons), brain, spleen
histopath- placenta, liver, heart, lung, brain
foetal fluids
foetal stomach contents
samples to take from stillborn lamb
fresh- placenta (at least two coteladons), brain, spleen
histopath- placenta, liver, heart, lung, brain, thyriod
foetal fluids
foetal stomach contents
confirm stillborn and not dystocis or neonatla death
did lamb walk/suck/breathe?
samples to take from bovine abortion
fresh- placenta (at least two coteladons), brain, spleen
histopath- placenta, liver, heart, lung, brain
foetal fluids
foetal stomach contents
samples to take from stillborn lamb
fresh- placenta (at least two coteladons), brain, spleen
histopath- placenta, liver, heart, lung, brain, thyriod
foetal fluids
foetal stomach contents
confirm stillborn and not dystocis or neonatla death
did lamb walk/suck/breathe?
weigh thyriod and check for congenital defects
