farm animal

steps to the diagnostic process

step 1 - data collection - CE, lab tests

step 2 - generating differenials

step 3 - rank differential diagnoses

step 4 - further investigation to enable differentiation of competing diagnoses

step 5 - closure

purpose of clinical examination

to identify clinical abnormalities that present and the risk factors that lead to disease in that individual or population

• can derive organs or system involved, location of a lesion, pathophysiological processess occuring

• can integrate clinical reasoning into our CE and further investigation may follow if insufficient evidence to reach a diagnosis

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stages of clinical exam

history - animal details and history

• age

• production stage

• clinical signs e.g sudden/slow milk drop, anorexia, diarrhoea

-herd history

background knowledge

• farm

• client

on farm

• full clinical examination

• sampling for labatory exam if required

• environment

• further history - housing, nutrition

• rest of herd

practical side

needs to be systematic and thorough

restrain patient safely

examine from distance and look at environment and herd mates

full CE in a cow takes a while

utilise overall framework

• general inspection

• vital signs

• specific exam

remember clinical exam signs could be thought of as tests with sensitivity and specific values

Cows are head shy and are used to being approached from behind

compared to horses and dogs!

• Tail end

• Udder

• L side – abdomen & chest

• R side – abdomen & chest

• Head

• Vaginal and/or rectal exam

tail end

temperature

• adult = 38.5 (38-39)

• calf = 39 (38.5-39.5)

• no rectal yet to avoid introducing air - avoid false ping on RHS

• vaginal discharge - any visible, metritis, endometritis, bulling

• urinary, could check mucus membrane colour

• faecal staining/faeces

• BCS

• coat condition

BCS

abdominal symmetry

left dorsal quadrant sticking out = normally bloat

chest - left and right

heart - listen under elbow - rib space 3-5

• normal adult = 60-80bpm

• calf = 80-120bpm

• murmurs - endocartitis

• quiet/ absence/ splashing - traumatic pericarditis

lungs

• adult 25 breaths/min

• calf 30 breaths/min

small lung field

not very informative

much damage by time get abnormal sounds

respiration rate

• observe, listen and count

left abdomen

rumen

• fill ( score 1-5)

• gas/bloat

• consistency of contents

movements - 3 every 2 mins

• bent fingers in L sub-lumbar fossa

eric williams test

• distinguish primary from secondary contractions

• diagnosis of wire, vagus indigestion

eric williams test

Palpation of rumen and auscultation of trachea

Primary cycle

• No sound

• Feel rumen contract

Secondary cycle

• Feel rumen contact

• Then hear eructation

Wire – grunt before Primary contraction

displaced abomasum

spontaneous

• tinkling and gurgling

ping - tap rib hard

• resonant ping

• indicates gas fluid interface

• map out area of pings

abscence of rumen sounds over displaced abomasum

fat cows = no ping

head

eye and nose

• conjunctiva - colour

• discharges

• lesions

LNs

• palpate

facial symmetry

CRT, skin tent

mouth

• pull tongue out to side

• drinkwater gag

• lesions

• ulcers/vesicles - FMD, BT, BVD/ mucosal disease, malignant catarrh, wooden tongue, IBR

right abdomen

listen

ping ( as for LDA)

• R displacement/ torsion of abomasum

udder

palpate

take milk sample

• always examine milk if lactating animal

• only if a reason in dry cow or suckler cow

clots and colour - changes can be discrete

california milk test

sterile milk sample for bacteriology

california milk test

add ewual amount of CMT mix to each ring and gently mix the 2 together using a swirling action

will colour the milk

rectal and vaginal exam

rectal

• Faeces consistency

• Presence of blood?

• Rectal tone

• Rumen

• Uterus & ovaries

• L kidney (midline or on RH side)

• Distended abomasum/caecum

vaginal

• discharge - calving date

• vaginal wall

• cervix - open/closed uterus and contents

• uterus and contents

skeletal examination

mostly foot but can get higher limb issues

calf exam

Remember initially they won’t have a functioning rumen!

Have neonate specific things you need to check for: joint ill, navel ill, congenital abnormalities

Specific history questions: calving history, colostrum intake (how much, how quickly, quality) etc

PPR

affects small ruminants

blunderbuss approach

examine from top to toe

get every conceivable test carried out

fit the results to a textbook model or vets own database of disease

• cumbersome

• expensive (multiple tests (false positives))

• unimaginative

• basis of some computer diagnostics

milk fever hypotheses generation

experience

• “older dairy cows who are recumbent after calving have milk fever”

physiology – work out from basics

• Calcium is required for muscle function and gut function

• Ca is likely depleted after calving in the older dairy cow

• a recumbent cow after calving with absence of faeces is likely due to low blood Ca = Milk Fever