physical examination of an animal after death to determine the abnormal and disease-related changes that occured during its life
necropsy
True or False: Disease doesn't necessarily mean sickness.
True
True or False: Learning and maintaining a systematic technique isn't mandatory when performing a necropsy examination!
False
Why do we perform necropsies?
to determine exact cause of death, accuracy of the clinical diagnosis, effects of treatment, and risk to other animals or people
What are the areas in which field necropsies are frequently performed:
If a suspected zoonotic disease, we can bury the body 6 feet below right in the field It is more convenient sometimes rather than transporting a large animal More cost efficient Prevents any contamination to the other animals in the field We could get quicker results rather than spending time taking them to a clinic
Obtain owner's written permission ____________ starting the necropsy!
before
True or False: Never freeze the body prior to necropsy!
True
What was be recorded if an animal was euthanized?
the date, time, method
What is the maximum time for a necropsy to be kept refrigerated?
24 hrs
True or False: All PPE and equipment does not have to be dedicated to necropsy to prevent the spread of disease to other animals and people.
False
Basic PPE requiered for ALL necropsy examinations include:
-scrubs -lab coat or coveralls -rubber boots or plastic booties over sneakers -latex or nitrile exam gloves (2 pair) -eye protection (glasses and/or goggles)
True or False: Always wear a mask and goggles when working with any of these wild or exotic species.
True
Additional PPE required when working with non-human primates:
-Latex or Nitrile gloves (2 pair)
Full face shield
Additional PPE required when working with avian species:
-Respirator (N95)
The following are commonly used to perform a necropsy exam:
-necropsy knives -scalpel handle and blades -scissors -forceps -utility scissors -ruler or measuring tape -bone-cutting forceps -hacksaw -lopping shears -string or hemostats
The destruction of tissues and cells by their own enzymes.
autolysis
Post-mortem autolysis and putrefaction occur simultaneously resulting in what?
decomposition
External microbial flora and internal normal flora break down tissues which results in color change, gas production, texture changes, and odor.
Putrefaction
What factors affect onset of post-mortem change?
-cause of death -environment temperature -body temperature at time of death -microbial flora present in the body
True or False: Bone survives for a long time after death of the body.
True
blood pooling on the dependent(down) side of the animal after death due to gravity
livor mortis
How long does the livor mortis proccess take till it begins?
within 30 minutes to one hour after death
contraction of the muscles after death resulting in rigidity of the body
rigor mortis
What are required for muscle relaxation and are depleted after death so the muscles contract?
ATP and glycogen
How long down Rigor Mortis take to begin and how long does it last?
one to six hours after death, and lasts for 1 to 2 days
What is another name for bloody nasal discharge?
purge fluid
What results from pressure changes exerted on the body as it decomposes?
reddish-brown, foul-smelling discharge from the oral and nasal cavities
the froth is only present in the distal 1/3 of the trachea
post-mortem change
the froth extends beyond the distal 1/2 of the trachea
pulmonary edema
can occur secondary to bloat as increase pressure is exerted on the abdominal cavity post-mortem
rectal and vaginal prolapse
What occurs as a result of post-mortem gas production in the lumen of the GI tract?
bloating
gas production occuring in tissues secondary to putrefaction
emphysema
increased darkening of the pigmentation of the tissues as a result of increased pigment-like granules in cells such as macrophages in the tissue
melanosis
Blue-green discoloration of the tissues results from the reaction of H2S production from bacterial putrefaction and iron from hemoglobin of lysed RBCs reacting to form iron sulfide
Pseudomelanosis
Red staining of tissues due to the breakdown of vessel walls and lysis of RBCs secondary to autolysis
Hemoglobin Imbibition
Whats the difference between a hemorrhage and hemoglobin imbibition?
-hemorrhage demonstrates sharp borders; dark red to black discoloration of tissues adjacent to normal tissues -hemoglobin imbibition lacks a sharp border; pale pink to red discoloration; and spreads smoothly throughout an entire tissue or organ
What is the other name of bile imbibition?
pseudoicterus
bile leakage from the gallbladder stains surrounding tissues a yellow to greenish-brown color
bile imbibition
Why are lymph nodes in young animals enlarged and reactive?
they are young and naiive
What can occur after death if the animal was struggling to urinate or defecate at the time of death?
Mucosal Reddening of the Colon and Bladder
Another name for mucosal reddening of the colon or bladder.
Tiger striped
Clouding of the lens of the eye when the body is frozen or chilled after death.
Post-mortem cataracts
True or False: Lenses will return to normal as the body warms.
True
Easily confused with true cataracts at time of necropsy if preservation of the body is unknown.
Post-mortem cataracts
Clotted blood pools after death and the heavier RBCs settle to the bottom of the clot with the yellow serum settling on the top
chicken fat clot
Where does post- mortem blood clotting occur within several hours after death?
heart and vessels
disease in which is transmissible from animal to man and vice versa
zoonotic disease
disease transmitted from people to animals
reverse zoonosis (anthroponosis)
How many zoonotic diseases are known to exist?
150
disease caused by previously unknown agents or by known agents in a species or location previously unknown
emerging zoonosis
How are these diseases transmitted?
-direct contact -vector-borne transmission -indirect contact -placental transmission
disease which pose significant threat to human and/or animal health
reportable disease
Why should these diseases be reportable?
-avoid devastation to livestock and poultry populations -prevent export bans on animals and animal-related products -eliminate the financial burden required to control or eradicate the disease -prevent establishment of wildlife reservoirs for disease which would complicate control and eradication
What is the causative agent for Tuberculosis?
Mycobacterium sp.
What is the primary zoonotic agent for Tuberculosis?
Mycobacterium bovis
Who are potentially infected with tuberculosis?
humans non human primates cattle rodents other mammals birds
What is the mode of transmission for Tuberculosis?
-inhalation of droplets (most efficient means of zoonotic transmission) -contaminated equipment -contact with contaminated urine, feces, or mucus secretions -bites -consumption of raw products
This disease affects every part of the body, is chronic, and is mainly characterized by pulmonary/respiratory involvement.
Tuberculosis
What are some symptoms of Tuberculosis in humans?
-fever, fatigue, and cough -chronic pulmonary disease (fatal) -lungs, kidneys and vasculature are all compromised
True or False: Tuberculosis is the highest risk for development of progessive pulmonary/extrapulmonary disease (1-2 years post infection).
True
True or False: Tuberculosis is treatable in people with a 6-month course of antibiotics.
True
What are some general signs of Tuberculosis in animals?
-weakness -anorexia -dyspnea -emaciation -low-grade fever
True or False: Tuberculosis may be asymptomatic and has a history of respiratory distress.
True
Where are granulomas typically found?
lymph nodes spleen liver lung body cavity surface
What does the culture and staining of Tuberculosis look like?
Mycobacterium is a gram positive, acid-fast red
What samples should be collected at necropsy for Tuberculosis diagnosis?
-culture from any abnormal lymph nodes or nodular organs (lungs, liver, spleen) -retropharyngeal, mandibular, supramammary, and mediastinal lymph nodes, and liver -samples for histopathology
Should samples for Tuberculosis be sent off for testing immediately?
Yes
True or False: Tuberculosis is a reportable disease.
True
What is known as the Woolsorter's disease?
Anthrax
What is the causative agent for Anthrax?
Bacillus anthracis
Who are potentially infected with anthrax?
-herbivores are primary host -ruminants are most susceptible to infection -humans and other mammals are accidental hosts
What are the modes of transmission for Anthrax?
-ingestion (GI tract) -inhalation of spores -cutaneous (skin exposure)
What is the most common route for animals to become infected with Anthrax?
Ingestion (GI tract) due to ingestion of spores from contaminated soil
What is the most common route for human infection with Anthrax?
Cutaneous (skin exposure)
What are the symptoms in humans with Anthrax?
-cutaneous form -inhalational form -ingestion -mortality from untreated cases
True or False: Anthrax is not easily treated with antibiotics.
False
True or False: Anthrax can progress to systemic bacteremia, septicemia, and death if untreated.
True
What disease progresses to fever, chills, recumbency, shock, collapse, and death within a few hours?
Anthrax
In Anthrax, what animals is recovery common in?
Pigs, dogs, and cats
What will you see at necropsy of anthrax?
poorly clotted dark blood from anus, vulva, nostrils, and mouth
What should carcasses be done to when dealing with Anthrax?
incinerated
True or False: With Anthrax, necropsies can be performed.
False
What would Anthrax look like under a microscope?
Spore forming encapsulated Gram-positive red
Is Anthrax a reportable disease?
Yes
What is also known as undalant fever, contagious abortion, or Bang's Disease?
Brucellosis
What is the most common mode of transmission for Brucellosis?
contact with placenta, fetus, fetal fluids, and vaginal discharge
Which disease is humans primarily infected cutaneously via contact with infected tissues/fluids?
Brucellosis
Which is one of the most serious diseases of livestock because it spreads so rapidly and is transmissible to humans?
Brucellosis
True or False: Anthrax is the most easily acquired laboratory infection.
False, Brucellosis
What are some symptoms in humans that have Brucellosis?
-flu-like symptoms -fever, aches, bacteremia, and granulomatous lesions -severe complications
What happens to cattle with Brucellosis?
-abortions -stillbirths -weak calves -testicular abscesses -arthritis
What happen to horses with Brucellosis?
-fistulous withers/poll-evil -abortions are rare
With Brucellosis, cattle at necropsy would have what throughout the reproductive tract, mammary tissues, spleen, liver, LN, kidneys, and lungs?
purulent lesions and granulomas
Which Brucellosis species is a reportable disease?
B. abortus
True or False: Brucellosis is destroyed by heat and sunlight exposure.
True
What are some sample collections with Brucellosis?
-stomach contents from aborted feti -afterbirth, placenta, fetal tissues -LN, spleen, liver, milk, semen, infected lesions -blood and serum
What does Brucellosis look like under a microscope?
Gram negative coccobacilli (shortened rods)
What is another name for the Bubonic Plague?
Black Death
What is the causative agent for Bubonic Plague?
Yersenia pestis
Who becomes infected with Bubonic Plague?
rodents: prairie dogs, squirrels, rats, field mice -sometimes humans, rabbits, and cats