NecropsyNecropsy

CRITICISMCRITICISM““Criticism, like rain, should Criticism, like rain, should be gentle enough to nourish be gentle enough to nourish

a man’s growth without a man’s growth without destroying his roots.”destroying his roots.”

-Franklin A. Clark-Franklin A. Clark

Necropsy – Fun at the Necropsy – Fun at the beachbeach

NecropsyNecropsy

Def: Examination of animal after it Def: Examination of animal after it died to determine the abnormal and died to determine the abnormal and disease-related changes that disease-related changes that occurred during its lifeoccurred during its life

DefinitionsDefinitions

Gross pathology – pathologic Gross pathology – pathologic changes seen with naked eyechanges seen with naked eye

Histopathology – clinical changes Histopathology – clinical changes seen with a microscopeseen with a microscope

Lesions – pathologic changesLesions – pathologic changes Pathogenesis – the sequence of Pathogenesis – the sequence of

events in the development of the events in the development of the diseasedisease

Reasons for necropsyReasons for necropsy

Determine cause of deathDetermine cause of death Determine accuracy of clinical diagnosisDetermine accuracy of clinical diagnosis Evaluate effects of therapyEvaluate effects of therapy In herds, 1 or more animals may be In herds, 1 or more animals may be

sacrificed to determine the cause of sacrificed to determine the cause of disease or toxicity disease or toxicity Contagious to other animals in herdContagious to other animals in herd InheritedInherited Toxins or environmental hazardsToxins or environmental hazards

Preliminary StepsPreliminary Steps

Obtain owner’s permissionObtain owner’s permission Correctly identify animal for Correctly identify animal for

necropsynecropsy Species, breed, sex, age, ID tags/tattoos Species, breed, sex, age, ID tags/tattoos

attached to record/formattached to record/form Perform necropsy ASAP after deathPerform necropsy ASAP after death

Refrigerate body if not performed Refrigerate body if not performed immediatelyimmediately

Do not freeze – destroys cells/tissueDo not freeze – destroys cells/tissue

Necropsy Report (working Necropsy Report (working report)report)

Generated during actual necropsyGenerated during actual necropsy Describe all abnormalitiesDescribe all abnormalities

Location of lesionsLocation of lesions Number of lesionsNumber of lesions Color Color ShapeShape DistributionDistribution ConsistencyConsistency Odor (sweet, sour, ammonia)Odor (sweet, sour, ammonia)

Final report – consistent tense (past vs Final report – consistent tense (past vs present)present)

FixativesFixatives

Stops autolysisStops autolysis Saves tissues for histopathologySaves tissues for histopathology 10% buffered formalin (carcinogen)10% buffered formalin (carcinogen) Sample thickness - 1 cm or lessSample thickness - 1 cm or less Ratio of fixative to sample = 10 to 1Ratio of fixative to sample = 10 to 1 Contact irritant and carcinogenContact irritant and carcinogen

Use gloves: keep containers closed, Use gloves: keep containers closed, handle in ventilated hoodshandle in ventilated hoods

Facilities and Facilities and InstrumentsInstruments

Well- lit, well-ventilated areaWell- lit, well-ventilated area Not surgical suite (contamination)Not surgical suite (contamination)

Prosector – person performing necropsyProsector – person performing necropsy Use caution when performing a Use caution when performing a

necropsy on site (farm) to prevent necropsy on site (farm) to prevent spread to other animalsspread to other animals

Wear protective clothingWear protective clothing Plastic apron, lab coat, scrubsPlastic apron, lab coat, scrubs Latex or plastic disposable glovesLatex or plastic disposable gloves Surgical mask if infectious/zoonotic disease Surgical mask if infectious/zoonotic disease

suspected (aerosolization)suspected (aerosolization) Protective footwearProtective footwear

Facilities and Facilities and InstrumentsInstruments

Protective ClothingProtective Clothing

InstrumentsInstruments

KnivesKnives ScissorsScissors Tissue forcepsTissue forceps Bone cutting Bone cutting

tools (pruning tools (pruning shears, shears, hacksaw)hacksaw)

CTVT pp 168-CTVT pp 168-169169

Miscellaneous ItemsMiscellaneous Items

Plastic containers of Plastic containers of formalin for samplesformalin for samples

Labeled sealable Labeled sealable plastic bagsplastic bags

Culture tubesCulture tubes

Sample CollectionSample Collection Contact diagnostic lab for directions on Contact diagnostic lab for directions on

collection, preservation and shipping of collection, preservation and shipping of specific samplesspecific samples

Possible microbiology samples-sterile Possible microbiology samples-sterile containerscontainers No preservativeNo preservative Do not freezeDo not freeze Primary disease site, LNPrimary disease site, LN Heart, blood, lung, liver, spleen stomach contents, Heart, blood, lung, liver, spleen stomach contents,

aborted fetuses, placenta, exudates, CSFaborted fetuses, placenta, exudates, CSF Tissue samples – 1x2x3 cm Tissue samples – 1x2x3 cm Fluid samples – 3-5 mlsFluid samples – 3-5 mls

Virus samples – call labVirus samples – call lab

Sample CollectionSample Collection

Toxicology samplesToxicology samples Blood – 10-20 mlsBlood – 10-20 mls Stomach contents and urine – 50-100 mlsStomach contents and urine – 50-100 mls Liver, fat, kidney and brain – 5x5x10 cm Liver, fat, kidney and brain – 5x5x10 cm

(200 g) – can be frozen(200 g) – can be frozen Rabies – head sent for testingRabies – head sent for testing

If suspected do not perform necropsy on rest If suspected do not perform necropsy on rest of body until proven negativeof body until proven negative

Cytology – smearsCytology – smears Blot surface gently, press tissue to surface of Blot surface gently, press tissue to surface of

slide, dryslide, dry

Tissue CollectionTissue Collection

Handle carefullyHandle carefully Do not stretch, squeeze or rinse with Do not stretch, squeeze or rinse with

waterwater Spread samples such as skin on Spread samples such as skin on

cardboard surface to retain shapecardboard surface to retain shape CLEAR IDENTIFICATION OF TISSUES CLEAR IDENTIFICATION OF TISSUES

– separate containers, labels, etc– separate containers, labels, etc

Preliminary DataPreliminary Data

Signalment – species, breed, sex, Signalment – species, breed, sex, color, age, weight, IDcolor, age, weight, ID

Clinical historyClinical history Available lab dataAvailable lab data Time of deathTime of death WeightWeight During necropsy, all organsDuring necropsy, all organs

External External ExamExam

Body conformationBody conformation Hair coatHair coat SkinSkin Any abnormal Any abnormal

findings in color or findings in color or appearanceappearance Bruises, Bruises,

lacerations, etclacerations, etc Also remove the eyes Also remove the eyes

at this pointat this point

Internal ExamInternal Exam Left lateral recumbencyLeft lateral recumbency Midline incision from right Midline incision from right

axilla to mandibular axilla to mandibular symphysissymphysis

Extend incision caudally to Extend incision caudally to perineumperineum Around prepuceAround prepuce Between mammaeBetween mammae

Reflect forelimb back with Reflect forelimb back with dissection between dissection between scapulae and ribsscapulae and ribs

Abdominal skin is Abdominal skin is reflectedreflected

Rear limbs are reflected Rear limbs are reflected by extending the incision by extending the incision into the coxofemoral jointsinto the coxofemoral joints

Internal ExamInternal Exam Now place in dorsal recumbencyNow place in dorsal recumbency Skin incision on cranial medial aspect of both Skin incision on cranial medial aspect of both

rear legs; reflect skinrear legs; reflect skin Collect samples ofCollect samples of

LN (mandibular, prescapular, axillary, inguinal, LN (mandibular, prescapular, axillary, inguinal, popliteal)popliteal)

Mammary glandsMammary glands TestesTestes skin skin

Examine several jointsExamine several joints Coxofemoral joint openedCoxofemoral joint opened Stifle jtStifle jt Scapulohumeral jtScapulohumeral jt

Internal ExamInternal Exam

Samples of sciatic nerve, synovium Samples of sciatic nerve, synovium with patella, skeletal musclewith patella, skeletal muscle

Bone marrow – upper midshaft Bone marrow – upper midshaft femurfemur

Internal Exam – Body Internal Exam – Body CavitiesCavities

AbdomenAbdomen Midline incision from sternum to symphysis Midline incision from sternum to symphysis

pubispubis Laterally from sternum along both costal Laterally from sternum along both costal

marginsmargins Reflect body wall laterallyReflect body wall laterally Puncture diaphragm – check for negative Puncture diaphragm – check for negative

partial pressure (hiss)partial pressure (hiss) Cut diaphragm from rib cageCut diaphragm from rib cage Cut ventral ribs away (utility scissors or Cut ventral ribs away (utility scissors or

pruning shears)pruning shears)

Internal Exam – Body Internal Exam – Body CavitiesCavities

Examine pleural surfacesExamine pleural surfaces Open pericaridal sacOpen pericaridal sac Examine exterior of heartExamine exterior of heart ID and remove thyroid, parathyroids, and ID and remove thyroid, parathyroids, and

thymusthymus ID and remove adrenal glands; sectionID and remove adrenal glands; section ExamineExamine

Salivary glands: mandibular, parotid, Salivary glands: mandibular, parotid, LN’sLN’s Jugular veinsJugular veins

Internal ExamInternal Exam Incise through intermandibular Incise through intermandibular

m. on inside of mandibles, m. on inside of mandibles, frenulum of tonguefrenulum of tongue

Reflect tongue caudally as the Reflect tongue caudally as the tongue , larynx, pharynx, trachea tongue , larynx, pharynx, trachea and esophagus, heart and lungs and esophagus, heart and lungs are removed as a unit – “pluck”are removed as a unit – “pluck” Includes aorta, vena cavaIncludes aorta, vena cava

Transect (cut) aorta, postcava Transect (cut) aorta, postcava and esophagus at diaphragm and and esophagus at diaphragm and remove as unitremove as unit

Open esophagus and trachea Open esophagus and trachea and examine and examine

Examine lungs; palpateExamine lungs; palpate

Internal ExamInternal Exam HeartHeart

Incise right auricle and atriumIncise right auricle and atrium Extend through right AV valve Extend through right AV valve

and along th interventricular and along th interventricular septum to apex of right septum to apex of right ventricleventricle

Examine surfacesExamine surfaces Incise into pulmonary arteries Incise into pulmonary arteries

into each lobe and examineinto each lobe and examine Squeeze sections of lung to Squeeze sections of lung to

assess fluid contentassess fluid content Remove heart and major Remove heart and major

vessels from lungsvessels from lungs Incise left auricle and into left Incise left auricle and into left

ventricleventricle Continue incision into aortal Continue incision into aortal Examine surfacesExamine surfaces

Internal ExamInternal Exam Abdominal CavityAbdominal Cavity

Remove intestines from cavityRemove intestines from cavity Strip mesentery from intestinesStrip mesentery from intestines Clamp and cut intestines distal to pancreas and Clamp and cut intestines distal to pancreas and

proximal to pelvic inletproximal to pelvic inlet Stomach, liver, spleen, pancreas and duodenum Stomach, liver, spleen, pancreas and duodenum

removedremoved Section spleenSection spleen Open stomach along greater curvatureOpen stomach along greater curvature Open duodenumOpen duodenum Squeeze gall bladder for patency of duct, then Squeeze gall bladder for patency of duct, then

openopen Separate liver and sectionSeparate liver and section

Abdominal CavityAbdominal Cavity Examine mesovarium, mesosalpinx and Examine mesovarium, mesosalpinx and

mesometrium if presentmesometrium if present Examine ovaries, oviducts and uterus if present Examine ovaries, oviducts and uterus if present

and reflect caudallyand reflect caudally Dissect left kidney freeDissect left kidney free

Slice longitudinally, peel capsuleSlice longitudinally, peel capsule Examine surface, cortex, medulla and pelvisExamine surface, cortex, medulla and pelvis

Examine ureters, palpateExamine ureters, palpate Open if dilatedOpen if dilated

Remove kidney, samples takenRemove kidney, samples taken Repeat for right kidneyRepeat for right kidney Open bladder and examineOpen bladder and examine Open urethraOpen urethra Examine prostateExamine prostate

Abdominal CavityAbdominal Cavity

IntestinesIntestines Examine by laying out on tableExamine by laying out on table Examine serosal surfaceExamine serosal surface Open from duodenum to colon with Open from duodenum to colon with

scissorsscissors Samples from each section, include Samples from each section, include

lesionslesions Handle mucosa carefully – easily Handle mucosa carefully – easily

damageddamaged