Block 1 Flashcards
Areas to avoid for necropsy (4)
● Areas accessible to animals/people
● Areas that may contain food
● High traffic areas
● Areas difficult to disinfect
Good area for necropsy (3)
● Concrete
● Dirt area in the sun (natural
disinfectant)
● Tarped area
Disposal options post necropsy (5)
b. Disposal options
i. Burial (must be deep enough!)
ii. Rendering
iii. Transport to a disposal site
iv. Incineration
v. Composting
All specimens should be handled and treated as if they are zoonotic. What are Routes of exposure to pathogens during a PM? (4)
i. Oral → wear masks
ii. Splash into eye → use eye protection
iii. Aerosolization
iv. Percutaneous (sharps injury)
External examination look at what?
Exam the skin, wounds, ectoparasites, feet (pads, claws, hooves). Exam eyes, ears, nose, and oral cavity (hemorrhage, blisters, exudate)
Carcass position:
Cows lie on what side? Why?
Horses?
Others?
Cows (ruminants)left because of rumen
Horses (equine) right because of cecum
Others doesn’t matter
Body cavity order (ATC) define
Abdomen
Thorax (confirm for negative pressure in the chest)
a. Remove the Pluck = heart, lungs, trachea, esophagus &
tongue
i. Reflect the tongue and larynx ventrally (to the side)
Cranium
Collection of microbiological samples should be done?
First!
Collected aseptically
Intestines are sampled last
Remove and dissect organs
Solids organs slide like what?
Incise organs with a what?
Open all chambers and valves of the heart by what ratio?
Brain?
Ingesta?
i. Solid organs → “Breadloaf” slice
ii. Organs with capsules need to be incised (ex: kidneys)
iii. Heart → open all chambers and valves
1. Should be 3:1 ratio between left and right ventricle
iv. Brain → always should be removed
1. 2 cuts on either side of foramen magnum & extend
2. 1 cut across the orbit
v. Ingesta → check for foreign material, toxic plants, feed quality, etc.
Formalin collection ratio should be?
10:1 ratio of formalin : tissue
a. Formalin will not penetrate more than 1⁄2 cm of tissue
b. Samples should be no more than 1cm thick
c. Animals <100g may be opened and fixed whole
Toxicology samples should be stored in what?
- Urine, stomach contents, fat, brain, kidney, liver
- Store in aluminum foil inside leak proof bags
Parasitology: external parasites should be preserved in what?
Ethanol
Cavitary effusions, culture store in what?
- Red top/Sterile tube → culture
- EDTA → fluid analysis and cytology
Explain how to properly finish a PM
Explain how to properly finish a PM.
a. Clean and disinfect work surfaces
b. Decontaminate self
c. Record necropsy findings
d. Package the samples
i. Do NOT freeze formalin
ii. Add padding and avoid glass if possible
e. Shipping the samples
i. Ship in leak-proof, crush-proof, well-labeled containers
Define autolysis
- Self-digestion or degradation of cells and tissues by host enzymes
- Occurs after somatic death due to hypoxia
- Tissues affected: Tissues with greater concentration of proteolytic
enzymes catalyze the quickest
— Pancreas first!, then GI, gallbladder, intestines, kidneys,
endocrine
Define Putrefaction
Process when post mortem bacteria breaks down tissues
2. Gives color, texture changes, gas production, odors
Rate of decomposition depends on what (3)
i. Cause of death
ii. Environmental and body temperature (Refrigerate prolong PM)
iii. Microbial flora
c. Examples
i. Rumen mucosa sloughing
ii. Pulpy kidneys
1. Accelerated renal autolysis associated with Clostridium perfringens type D septicemia (happens post mortem)
What is Rigor mortis?
- Contraction of the muscles after death
- Begins 1-6hrs post death, persists for 1-2 days
- High heat and high activity before death increase rigor
- Due to depletion of ATP and inability of myosin to detach from the
actin binding site
What is Algor mortis
- Cooling of the body post mortem
- Depends on the body temperature at the time of death
a. Brain temperature decreases ~18hrs after death
b. Other sites (wool, fat)
What is Livor mortis?
- Gravity pulls the blood post death (blood pooling)
- Variation in color of tissues (skin, lung, kidneys)
What is post-mortem blood clotting?
- Occurs several hours after death in the heart and vessels
- Chicken fat clot → due to seperation of RBCs and clotted serum
a. Proteins that would have been in the serum combine and
form a jelly-like clot & turns yellowish
What is Antemortem clot
Attached to vessel walls
● Dull and dry
● Laminated
● Friable
What is postmortem clot
● Unattached
● Shiny and wet
● Elastic
● Fills the lumen of a vessel
What is hemoglobin imbibition?
- Red staining of tissue (especially the heart, arteries and veins)
- Hb is released by lysed RBCs, penetrates the vessel wall, and
extends into the adjacent tissues
What is Bile imbibition?
- Green staining due to bile in the gallbladder penetrating the adjacent tissues
- Tissues Affected = those in contact with the gallbladder
(liver, intestines, diaphragm)
What occurs to the eye postmortem?
- Corneal opacity due to dehydration of cornea
- “Cold cataracts”
What is pseudomelanosis?
- Greenish-black discoloration of tissues PM
- Decomposition of blood by bacterial action forming
hydrogen sulfide with iron - Occurs soon after death
- Tissues affected = tissues in contact with the gut
(kidney, liver, spleen, gut wall)
What is postmortem bloat?
- Results from PM bacterial gas formation in the lumen of GI tract
- Herbivores bloat faster! → more bacteria in diet
- Associated changes with antemortem (before death) Bloat:
a. Rectal/vaginal prolapse
b. Froth in trachea
c. Ruptured viscera → hemorrhage!
d. Bloat line → area of distinction on the esophagus where
the blood vessels supplying the pluck are blocked due to
bloat of the rumen/ruminal tympany
Why is Ingesta in the trachea → Just on top of the trachea, not a real finding!?
Would have inflammation if it was antemortem
Explain the difference between a description and a MDx.
a. Description
i. Describes what you see
ii. Precise word picture
iii. Generally the description is not subjective or interpretive
b. Morphological Diagnosis
i. Interprets the description and makes subjective conclusions
WHAT IS PATHOLOGY?
Pathology is the study of disease
What does a pathologist (DACVP/PhD) study???
(5)
Etiology
Pathogenesis
Disease
Molecular & morphologic changes
Clinical manifestations
WHAT IS PATHOLOGY?
Etiology
define
examples
Etiology Ǖ cause of disease
ex. viruses, bacteria, fungi, parasites
WHAT IS PATHOLOGY?
Pathogenesis
define
Pathogenesis Ǖ the sequence of events that lead to disease
WHAT IS PATHOLOGY?
Disease
define
Disease Ǖ any deviation from the normal structure or function
WHAT IS PATHOLOGY?
Molecular & morphologic changes
define
Molecular & morphologic changes Ǖ biochemical and structural alterations of the cells and
organs
WHAT IS PATHOLOGY?
Clinical manifestations
define
Clinical manifestations Ǖ clinical signs that are a result of functional abnormalities of tissue
IMPORTANT DEFINITIONS TO KNOW
Diagnosis (Dx)
Diagnosis (Dx) = concise statement concerning the nature, cause
and name of a disease
IMPORTANT DEFINITIONS TO KNOW
Disease name
Disease name = encapsulates host, morphology and cause of the
disease
Ex. Bovine viral diarrhea
IMPORTANT DEFINITIONS TO KNOW
Lesion
Lesion = any morphological change in tissues during disease
IMPORTANT DEFINITIONS TO KNOW
Pathognomonic lesion
Pathognomonic lesion
= characteristic of a specific disease
In other words, you should only see it associated with one disease!!
Ex. diamond skin disease in pigs with Erysipelothrix rhusiopathiae
Ex. canine herpes virus-1 (CHV-1) causes multifocal hemorrhagic nephritis
GENERAL V. SYSTEMIC PATHOLOGY
General Pathology
define
what does it apply to
General Pathology:
applies to ALL cells, organs and tissues
main pathological processes incited by
various injurious stimuli
GENERAL V. SYSTEMIC PATHOLOGY
Systemic Pathology
define
how does it relate to tissues? diseases?
Systemic Pathology
system-specific disease processes
tissues are unique - therefore, they will have
different responses to injury!
diseases specific to different systems of the body
PATHOLOGICAL PROCESSES
Know these 5 and always relate what you learn this
semester to the pathological process!!
what are the 5?
- Degeneration & Necrosis
- Inflammation & Repair
- Circulatory Disorders
- Disorders of Growth
- Deposits & Pigmentations
PATHOLOGICAL PROCESSES
Know these 5 and always relate what you learn this
semester to the pathological process!!
what is degeneratation and necrosis
cell injury
PATHOLOGICAL PROCESSES
Know these 5 and always relate what you learn this
semester to the pathological process!!
what is inflamation and repair
acute v. chronic/fibrosis
PATHOLOGICAL PROCESSES
Know these 5 and always relate what you learn this
semester to the pathological process!!
what is circularoty disorders
congestion, thrombosis, DIC
PATHOLOGICAL PROCESSES
Know these 5 and always relate what you learn this
semester to the pathological process!!
what is disorders of growth
neoplasia, developmental amonalies
what is this an example of?
what is the diagnosis?
Example:
MDx: Multifocal necro-hemorrhagic nephritis
Cause (Etiology): Canine herpesvirus-1
EDx: Herpesviral nephritis
Example of a pathognomonic lesion…
* MDx: Multifocal necrohemorrhagic nephritis
* Cause (Etiology): Canine herpesvirus-1
* EDx: Herpesviral nephritis
* Pathogenesis: infection with canine herpesvirus-1 viral
replication in endothelial cells endothelial cell injury and
inflammatory response multifocal necro-hemorrhagic
nephritis
* Disease name: Fading puppy syndrome (or Canine Herpes)
PULPY KIDNEY DISEASE
what is it?
when does it occur?
when is it fatal?
what causes it?
Accelerated renal autolysis
Seen with Clostridium perfringens type D
- post-mortem change but associated w/ disease
- production of large amounts of enterotoxins
leading to enterotoxemia
Fatal disease in sheep and cattle
- seen when there is a sudden change to a low-
fiber, high-carbohydrate diet
BLOOD CLOTS: ARE THEY POST-MORTEM
OR ANTEMORTEM?
characteristics of post-mortem are?
Post-Mortem Clot:
Unattached
shiny
Wet
elastic
Fills the lumen of
a vessel
BLOOD CLOTS: ARE THEY POST-MORTEM
OR ANTEMORTEM?
Ante-Mortem Clot (Thrombus)
characteristics of an ante-mortem clot are?
Ante-Mortem Clot (Thrombus):
Attached to vessel walls
Dry and dull
Laminated
Friable
CHICKEN FAT CLOT
why does it have a unique appearance?
what is the consistency?
Unique appearance due to
separation of RBCs and
clotted serum
Yellow in color and rubbery in
consistency
HEMOGLOBIN & BILE IMBIBITION
Hemoglobin Imbibition
what is it?
where is it found?
Hemoglobin Imbibition:
Red staining of tissue because hemoglobin is
released by red blood cells, penetrates vessel
wall and extends into the adjacent tissues
Found in the heart and large arteries/veins
HEMOGLOBIN & BILE IMBIBITION
Bile Imbibition
what is it?
where is it found?
Bile Imbibition:
Bile in the gallbladder penetrates
the walls and stains adjacent
tissues yellow/greenish/brown
Found in the liver, intestines and
diaphragm
RUMINAL TYMPANY
what is it?
what causes it?
how/where do you identify it?
what do you see?
An ANTEMORTEM change
- accumulation of gas
Look for esophageal bloat line
during necropsy
Blood is unable to pass this demarcated
line
CORNEAL OPACITY
what is it?
another name?
what causes it?
Post-mortem change
“Cold cataracts”
Comes from the dehydration of the cornea
- drying of the exterior surface and absorption
of aqueous humor
HOW DOES THIS DARK GREENISH-
BLACK DISCOLORATION OCCUR POST-
MORTEM? WHAT IS IT CALLED?
PSEUDOMELANOSIS
PSEUDOMELANOSIS
what is it?
where is it commonly found?
what causes it?
when does it occur?
Greenish-black discoloration of tissues post-
mortem
Commonly seen in tissues in contact with
the intestines: kidney, liver, spleen,
Comes from the decomposition of blood by
bacterial action forming hydrogen sulfide
with iron
Occurs soon after death
IS THIS A POST-MORTEM CHANGE?
what is it?
Purge Fluid - reddish fluid coming from the nose
Yes! Changes in vascular pressures post-mortem allow for leakage
IS THIS A POST-MORTEM CHANGE?
what it is called?
Splenomegaly Ǖ enlargement of the spleen
Yes! Barbiturates in euthanasia solution may result in this post-mortem
change
IS THIS A POST-MORTEM CHANGE?
what is it called?
Ingesta in the trachea
POSSIBLY!
When would it be normal? Stomach contents could have just leaked out
when moving the body
When is it not normal? If inflammation is present
IS THIS A POST-MORTEM CHANGE?
what is it called?
Intussusception Ǖ intestines folding in on one another
POSSIBLY!
When is it normal? Ongoing persitalsis after death Ǖ easily pulled apart at necropsy
When is it not normal? May have hemorrhage Ǖ not easily pulled apart at necropsy
IS THIS A POST-MORTEM CHANGE?
whta is it called
Urinary Bladder of a Horse
This is calcium carbonate and mucus Ǖ a normal finding in the equine urinary bladder
OTHER NORMAL FINDINGS
BECAUSE HORSES ARE WEIRD
what are they and where are they located?
Spleen Ǖ Capsular Indentation
Placenta Ǖ Cervical Star
Tongue Ǖ Lingual Hyperkeratosis
WHAT SPECIES CAN WE
SEE THESE NORMAL FINDINGS???
Rumenoreticular Groove Ǖ Ungulate Papillae
Aborted CalfǕ Amniotic Plaques
cow
WHAT ROLE DO THESE NODULES PLAY
IN THE BODY?
Feline Small Intestine Ǖ Peyer’s Patches
WHAT ARE THESE FINDINGS CALLED
AND WHAT SPECIES DO WE FIND THEM
IN?
Llamas Ǖ Gastroliths
White-Tailed Deer Ǖ Hemal Nodes
TELL ME WHAT YOU SEE!!!
DESCRIPTION V. INTERPRETATION
what is the description?
what is the interpretation?
Description:
NOT subjective or
interpretive
What do you see? Create
a picture!
Ex. “large mass that is
encapsulate and full of a
thick yellowish fluid”
Interpretation:
Takes a description and
makes an
interpretation/conclusion
A “best guess”
Ex. Abscess
SHAPE
raised
Raised: something has been added
- neoplastic cells, edema
SHAPE
depressed
Depressed: something has been lost
- necrosis
SHAPE
Geometric
Geometric: lesion follows vasculature
- Erysipelothrix rhusiopathiae involves infarction
SHAPE
Straight lines
Straight lines: lesion follows an anatomic
structure
- blood vessel, nerves, bronchioles
DISTRIBUTION
Multifocal
Multifocal: numerous similar lesions of variable size
- coalescing ĺ lesions are coming together
Ex. Metastasis of a tumor to the lung creating nodules
DISTRIBUTION
Multifocal coalescing
lesions are coming together
DISTRIBUTION
Diffuse
Diffuse: throughout a large portion of the effected tissue
- evenly spread out
DISTRIBUTION
Locally extensive
in one area of the tissue (local); symmetrical or
asymmetrical
*symmetrical indicates systemic/metabolic cause of the lesion
Morphologic Diagnosis:
Cause/Etiology
Disease name:
Morphologic Diagnosis:
Heart – pericarditis, fibrinosuppurative, diffuse, chronic,severe
Cause/Etiology – bacterial introduction from the reticulum
Disease name: Hardware disease
MDx:
EtDx:
MDx:
Heart – Valvular endocarditis, locally extensive, chronic,severe
EtDx:
Bacterial endocarditis
MDx:
EtDx:
Disease name:
MDx:
Kidney – Nephritis, chronic, multifocal, severe
EtDx: Coronaviral nephritis
Disease name: Feline Infectious Peritonitis (FIP)
MDx:
EtDx:
Disease name:
Etiology:
MDx:
Liver – hepatic necrosis, focal,subacute, severe
EtDx:
Clostridial hepatic necrosis
Disease name: Black disease or Infectious Necrotic Hepatitis
Etiology: Clostridium novyii
