Anatomical Path Exam 1

Define necropsy

a physical exam of an animal after death to determine the abnormal and disease-related changes that occured during its life

several reasons why we perform necropsies in vet med

exact cause of death when other diagnostic testing fails to yield one

determine the accuracy of the clinical diagnosis

give vet team and owner closure

determine effects of treatment

determine risk to other animals or people with zoonotic diseases

how long after an animal dies should you wait to perform the necropsy

as long as it takes to get owner’s written permission. it is best to perform necropsy as soon as possible

are fresh, refrigerated, or frozen specimens best for necropsy

fresh. refrigerated and frozen specimens compromise the integrity of the samples by forming ice crystals and condensation.

for how long can you refrigerate an animal for necropsy

24 hours

why is freezing an animal before necropsy the least ideal option

ice crystals will form and create artifact

what PPE is required for you to perform a routine necropsy on a small or large mammal with no suspected zoonotic, reportable, or foreign animal disease

scrubs, lab coat or coveralls, rubber boots or plastic booties over sneakers, latex or nitrile (2 pair), eye protection, safety glasses for small goggles for large animal

what PPE is optional for necropsy for small and large animals

plastic apron

surgical mask or respirator

what additional PPE has to be worn when performing a necropsy on avians

mask and goggles always worn

2 pari of latex or nitrile gloves

full face shield

a respirator is recommended

what are some reasons we perform field necropsies

if a suspected zoonotic disease, we can bury the body 6 feet below right in the field

convenience

cost efficient

prevents any contamination to other animals in the field

quicker results

define decomposition

post-mortem autolysis and putrefaction occurring simultaneously

define autolysis

destruction of tissues and cells by their own enzymes

self-digestion or self-death

define putrefaction

external microbial flora and internal normal flora break down tissues which results in color change, gas production, texture changes, and odor

name two factors other than cause of death which determine how quickly decomp occurs

environmental temp

body temp at time of death

microbial flora present in the body

what is liver mortis and about how long after death does this occur

begins 30 minutes to 1 hour after death

blood pools on the depended (down) side of the animal after death due to gravity

what is bloat and about how long after death does this occur

result of post-mortem gas production in the lumen of the GI tract

more severe and commonly seen in herbivores due to normal gas production taking place which is removed by eructation

if severe can rupture diaphragm and create positive pressure

can also lead to prolapse and discharge

which post-mortem changes did we discuss that are caused secondary to gas production in the gut post-mortem

bloody nasal discharge or purge fluid

rectal and vaginal prolapse

what is one way you may differentiate purge fluid from bleeding associated with traumatic injury

no injuries are detected like a traumatic injury would

differentiate between frothy nasal discharge and froth from respiratory condition

post mortem: froth only present in distal 1/3 of the trachea

Pulmonary Edema: the froth extends beyond the distal 1/3 of the trachea

what is emphysema

gas production occurring in tissues secondary to putrefaction

which post-mortem change is associated with staining from the gall bladder

bile imbibition

also known as pseudoicterus

occurs secondary to autolysis and occurs within hours of death

which post-mortem change is associated with staining of surrounding tissues as RBCs and blood vessels break down

hemoglobin inbibition

begins several hours after death

which post-mortem change is associated with dark blue-green discoloration which appears like melanosis

Pseudomelanosis

what causes pseudomelanosis to occur and how long after death does it appear

may not form until 24 hours after death depending on amount of bacteria

results from reaction of the H2S production from bacterial putrefaction and iron from hemoglobin of lysed RBCs reacting to form iron sulfide

hemorrhage

sharp borders and dark red to black discoloration of tissues adjacent to normal tissues

hemoglobin imbibition

lacks a sharp border and demonstrates a pale pink to red discoloration. spread smooth and gradually

how to determine if it is prolapse or intussusception

correct the prolapse or intussusception

if it is difficult, the body had time to react and it was before death

how to determine if blood clot is before or after death

post-mortem: shiny, wet, unattached and forms cast

Antemortem: dull, dry, attached, and have tail extending from point of attachment

Term for blood clots that form after death

Chicken Fat Clot

Tuberculosis causative agent

Mycobacterium tuberculosis

Mycobacterium bocis: primary zoonotic

Mycobacterium avium

Mode of transmisson for tuberculosis

inhalation of droplets: most efficient

contaminated equipment

contact with contaminated urine, feces, or mucus

Bites from infected

consumption of raw dairy

Anthrax causative agent

Bacillus anthracis

modes of transmission for Anthrax

Ingestion (GI Tract): most common for animals

inhalation of spores

cutaneous: most common for humans

Brucellosis causative agent

B. abortus: cattle, bison, water buffalo, horses

B. melitensis: sheep and goats

B. suis: pigs, horses

B. canis: dogs

Brucellosis modes of transmission

contact with placenta, fetus, fetal fluid, and vaginal discharges of infected

contact with blood, milk, urine, semen

ingestion

cutaneous

fomites: milking cows

aerosilization

Plague causative agent

Tersenia pestis

Plague modes of transmission

flea bites: humans via oriental rat flea

direct contact with infected animals via MM and broken skin

aeroslization

ingestion

Leptospirosis causative agent

Leptospira species

modes of transmission for Leptospirosis

cutaneous: most common

ingestion

aerosilization

Ornithosis causative agent

Chalmydophila psittaci

modes of transmission for Ornithosis

aerosilization

ingestion

fomites, feathers, tissues

mechanical transmission via lice, mites, and other insects

Tularemia causative agent

Francisella tularensis

F. tularensis tularensis (Type A) is most virulent

Modes of transmission for Tularemia

arthorpod vectors and deer flies, most common for animals

cutaneous: most common for humans

ingestion: second most common for humans

inhalation

Rabies causative agent

Lyssavirus species

mode of transmission for rabies

bite wounds, mucous membranes contaminated

aerolization: bat caves

Avian influenza causative agent

Type A influenza virus (Orthomyxoviridae)

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