Fa Med - Brdc Diagnosis

Front 1

Characterization of disease
-define

Back 1

-why is the animal sick?

Front 2

Characterization of disease
-requires what

Back 2

-investment in diagnostic tests and post mortem exams

Front 3

Case definition
-define

Back 3

-description of an animal that meets your requirements for receiving treatment or for treatment success/failure

Front 4

Reason for a case definition

Back 4

-must define a disease before you can effectively treat it

Front 5

Case definition
-challenges

Back 5

-develop your own ability to recognize disease
-make sure you are comfortable with normal

*then help clients define disease

Front 6

Case definitions need to be characterized as:

Back 6

-important
or
-misleading

Front 7

BRD
-example case definitions

Back 7

-depression
-nasal discharge
-ocular discharge
-rumen fill/appetite
-rectal temp
-auscultation

*images in ppt

Front 8

BRD
-depression scoring system

Back 8

-0 = normal, no signs of depression
-1 = slower than pen mates but perks up when approached and does not appear weak, actively follows your movements with a raised head
-2 = stands with head lowered, will perk up when approached but will return to depressed stance, moves slowly and falls towards back of group, may display signs of weakness such as incoordination
--3 = obviously very weak, difficulty in moving with group, raises head only when approached closely

Front 9

Why is it so difficult to visually ID BRD positive cattle?

Back 9

-prey species
-look at humans as predator so want to hide disease from doctor

Front 10

Caudal vena caval syndrome
-describe

Back 10

-liver abscesses located near the vena cava erode the blood vessel and eventually the lungs get bathed in blood

Front 11

Tendencies of production animal vets

Back 11

-call less animals ill

*wrong

Front 12

Tendencies of individual animal vets

Back 12

-call more animals sick

*wrong

Front 13

BRD
-what do we know about diagnosing

Back 13

Clinical illness scores + rectal temp > 40C (104F)
-63% specificity

Lung evaluation at harvest: gross evaluation
-90% specificity

Front 14

BRD
-what does a rectal temp of <105F tell us

Back 14

-there are some who can't get a difference between outcome success and failure
-population could reflect true population fatality rates

Front 15

BRD
-typical rectal temp cut-off

Back 15

- >104F = probably will need intervention for treatment

- <104F = most respond spontaneously

Front 16

Stethoscope
-exam findings

Back 16

-crackles and wheezes = likely significant
-hear nothing = likely significant because there is no air flow (consolidation)
-hear nothing abnormal = possibly still abnormal

Front 17

Stethoscopes
-false sounds may come from

Back 17

-environment
-hot cattle

Front 18

diagnostic equipment necessary for physical exam

Back 18

-stethoscope

Front 19

Ultrasound
-use in BRD diagnosis

Back 19

-98% specificity
-use with auscultation
-ultrasound waves can't go through air, so if lots of lung tissue is seen ---> consolidation

Front 20

Ultrasound
-limitations

Back 20

-experience
-can't see consolidation if attached to pleura

Front 21

Blood work
-will this give you a perfect BRD diagnosis?

Back 21

-no
-CBC and biochem show little benefit in acute respiratory disease diagnosis

Front 22

Blood work
-only significant finding

Back 22

-fibrinogen (will not predict pneumonia)

Front 23

Blood work
-problems with reference intervals

Back 23

-normal for adult middle-aged cows
-mature bulls ---> lower WBCs
-calves ---> high GGT

Front 24

Why is GGT high in calves?

Back 24

-high in milk and colostrum

Front 25

Infrared thermography
-function

Back 25

measure heat of dorsal planum
-calves with >10% consolidation 22.9C
-calves with <10% consolidation 18.7C

Front 26

Infrared thermography
-limitations

Back 26

-a lot of potential environmental confounders

Front 27

Advanced imaging
-best specificity

Back 27

Radiographs < CT < MRI

*none are perfect

Front 28

Necropsy
-benefits

Back 28

-visual assessment
-histology
-culture

Front 29

How to diagnose and individual animal with BRD with everything at your disposal

Back 29

-excellent physical exam
-ancillary diagnostic tests as required

Front 30

How to diagnose a population with BRD with everything at your disposal?

Back 30

-create a case definition (understand limitations)
-

Front 31

What is important for being able to diagnose disease?

Back 31

-educate and be educated by staff

Front 32

Why are adult feedlot cattle with BRD different from calves?

Back 32

less pronounced:
-effort
-nasal discharge
-ocular discharge

Front 33

What age group of cattle should you practice physical exams on?

Back 33

-adults