7 examination of respiratory system

Education

1. Examination of the respiratory
system
Dr. Karima Al salihi

2. •Respiratory disease is common in cattle.
•Conditions affecting the respiratory system may
be acute, chronic, mild or severe. Some of these
conditions are sporadic whereas others may have
a high morbidity.
•The economic losses and the animal welfare
implications of respiratory disease associated with
pulmonary disease can be severe and should not
be underestimated.
•In particular, pneumonia and lungworm may
have a high morbidity and can be clinically severe.

4. most reliable way to obtain the respiration rate. It is
preferable to have the animal in the standing posi-
tion, as abnormalities can be modified by recum-
bency and may be missed. On a cold winter’s day the
respiratory rate can be counted accurately by observ-
ing the plume of condensation from the nostrils on
expiration.
Conditions causing respiratory
disease
Conditions of calves
These may include enzootic pneumonia, infectious
bovine rhinotracheitis (IBR), parainfluenza 3 (PI3),
respiratory syncytial virus (RSV), bovine viral diar-
rhoea (BVD), mycoplasmas, Pasteurellaand foreign
body pneumonia.
Conditions of growing cattle
These may include IBR, RSV, lungworm, Pasteurella
andHaemophilus.
Conditions of adult cattle
These may include chronic suppurative pneumonia,
caudal vena caval syndrome, tuberculosis, fog fever,
diffuse fibrosing alveolitis (bovine farmer’s lung),
pasteurellosis and lungworm.
CHAPTER 7
66
Cranial part of apical lobe
of right lung
Cardiac lobe
Apical lobe
Diaphragmatic lobe
Right lung (lateral aspect)
Left lung (lateral aspect)
Cardiac lobe
Intermediate
lobe
Apical lobe
Diaphragmatic lobe
Figure 7.1Left lung (lateral aspect) and
right lung (lateral aspect).

5. Normal breathing
•In normal cattle there is relatively little movement of the rib cage during
respiration.
•Some movement of the abdominal muscles is usually seen just behind the rib
cage during each inspiration, and this should be symmetrical.
•The normal respiratory volume in the adult is 3 to 8 litres.
•In healthy cattle breathing is normally costoabdominal, with a small thoracic
component and a small abdominal component.
•The ratio of the duration of inspiration to expiration in cattle is 1.0 : 1.2, with
a short pause at the end of expiration.
•The normal resting respiratory rate in cattle is 15 to 35 breaths per minute
and in calves it is 20 to 40 breaths per minute.
•Counting breaths by observation of rib movements at the costal arch and
the flank from a position behind and to one side of the animal is the most
reliable way to obtain the respiration rate. It is preferable to have the animal
in the standing position, as abnormalities can be modified by recumbency
and may be missed.
• On a cold winter’s day the respiratory rate can be counted accurately by
observing the plume of condensation from the nostrils on expiration.

6. Conditions causing respiratory disease
•Conditions of calves
These may include:
enzootic pneumonia,
infectious bovine rhinotracheitis (IBR),
parainfluenza 3 (PI3),
respiratory syncytial virus (RSV),
bovine viral diarrhoea (BVD),
mycoplasmas,
Pasteurella and
foreign body pneumonia.
Conditions of growing cattle
These may include IBR, RSV, lungworm, Pasteurella and Haemophilus.

7. Conditions of adult cattle
These may include chronic
suppurative pneumonia, caudal
vena caval syndrome, tuberculosis,
fog fever, diffuse fibrosing
alveolitis (bovine farmer’s lung),
pasteurellosis and lungworm.

8. Clinical Examination of the Respiratory System
67
Scapula
Trachea
Rumen
Costochondral
junction
Xyphoid
Spleen
Reticulum
Sternebrae
Heart
Humerus
Diaphragmatic lobe
Shoulder
joint
Cardiac
lobe
1
6
13
Apical
lobe
Lung
Diaphragm
Thoracic vertebrae
Figure 7.2Left lung in situ.
Shoulder
joint
ScapulaSpinal vertebrae
Liver
13
6
Cardiac lobe
Apical lobe
Intermediate lobe
Diaphragmatic
lobe
Small
intestine
Costochondral
junction
Abomasum
Omasum
Xyphoid Heart
SternebraeFigure 7.3Right lung in situ.
Clinical Examination of the Respiratory System
67
Scapula
Trachea
Rumen
Costochondral
junction
Xyphoid
Spleen
Reticulum
Sternebrae
Heart
Humerus
Diaphragmatic lobe
Shoulder
joint
Cardiac
lobe
1
6
13
Apical
lobe
Lung
Diaphragm
Thoracic vertebrae
Figure 7.2Left lung in situ.
Shoulder
joint
ScapulaSpinal vertebrae
Liver
13
6
Cardiac lobe
Apical lobe
Intermediate lobe
Diaphragmatic
lobe
Small
intestine
Costochondral
junction
Abomasum
Omasum
Xyphoid Heart
SternebraeFigure 7.3Right lung in situ.

9. Clinical Examination of the Respiratory System
67
Scapula
Trachea
Rumen
Costochondral
junction
Xyphoid
Spleen
Reticulum
Sternebrae
Heart
Humerus
Diaphragmatic lobe
Shoulder
joint
Cardiac
lobe
1
6
13
Apical
lobe
Lung
Diaphragm
Thoracic vertebrae
Figure 7.2Left lung in situ.
Shoulder
joint
ScapulaSpinal vertebrae
Liver
13
6
Cardiac lobe
Apical lobe
Intermediate lobe
Diaphragmatic
lobe
Small
intestine
Costochondral
junction
Abomasum
Omasum
Xyphoid Heart
SternebraeFigure 7.3Right lung in situ.
Clinical Examination of the Respiratory System
67
Scapula
Trachea
Rumen
Costochondral
junction
Xyphoid
Spleen
Reticulum
Sternebrae
Heart
Humerus
Diaphragmatic lobe
Shoulder
joint
Cardiac
lobe
1
6
13
Apical
lobe
Lung
Diaphragm
Thoracic vertebrae
Figure 7.2Left lung in situ.
Shoulder
joint
ScapulaSpinal vertebrae
Liver
13
6
Cardiac lobe
Apical lobe
Intermediate lobe
Diaphragmatic
lobe
Small
intestine
Costochondral
junction
Abomasum
Omasum
Xyphoid Heart
SternebraeFigure 7.3Right lung in situ.

10. Manifestations of respiratory disease
affected and number of deaths should be ascer-
tained. The history may suggest the severity and
chronicity of the outbreak.
Predisposing risk factors
The presence or absence of predisposing risk factors
should be established, some of which are listed
below.
Calf pneumonia
Stress– Large diurnal temperature fluctuations,
failure of passive transfer, weaning, housing,
transport, disbudding, castration
Vaccination– Vaccine(s) used, date administered, age
of calf, method of administration and protocol
used
Age– Common in housed calves 1 to 4 months of age
Source of infection– Bought-in calves, mixing calves of
different ages, common air space, pens in contact
Growing cattle/adult cattle pneumonia
Stress– Large diurnal temperature fluctuations,
housing, transport, mixing, markets
Vaccination– Vaccine(s) used, date administered,
method of administration and protocol used
Source of infection– Bought-in animals, return from
show, common air space, pens in contact
Biosecurity– Non-compliance with protocols
Lungworm– Vaccination and anthelmintic pro-
grammes, recurrent problem on farm
Fog fever– Adult cattle grazing with unlimited access
in the aftermath of haymaking
Infectious bovine rhinotracheitis (IBR)– A dairy herd
in which IBR is present may show reduced milk
yield.
Examination of the environment
If the outbreak occurs during the housing period,
careful inspection should be made to identify predis-
posing risk factors. These include poor ventilation,
high humidity, overcrowding, poor quality bedding,
large groups, common air spaces and mixing animals
of different ages.
Clinical Examination of the Respiratory System
69
Abdominal breathing line
Elbows abducted
Froth
Mouth open
Protruding
tongue
Purulent
nasal
discharge
Head lowered
and extended
Ears drooping
Roughened
staring coat
Figure 7.6Some clinical signs which may be observed in cattle with severe respiratory disease.

11. Predisposing risk factors
The presence or absence of predisposing risk factors should be
established, some of which are listed below.
Calf pneumonia
Stress – Large diurnal temperature fluctuations, failure of passive
transfer, weaning, housing, transport, disbudding, castration
Vaccination – Vaccine(s) used, date administered, age of calf, method
of administration and protocol used
Age – Common in housed calves 1 to 4 months of age Source of
infection – Bought-in calves, mixing calves of different ages, common
air space, pens in contact
Growing cattle/adult cattle pneumonia
Stress – Large diurnal temperature fluctuations, housing, transport,
mixing, markets

12. Growing cattle/adult cattle pneumonia
1. Stress – Large diurnal temperature fluctuations, housing,
transport, mixing, markets
Vaccination – Vaccine(s) used, date administered, method of
administration and protocol used
Source of infection – Bought-in animals, return from show,
common air space, pens in contact
Biosecurity – Non-compliance with protocols
Lungworm – Vaccination and anthelmintic programme, recurrent
problem on farm

Fog fever – Adult cattle grazing with unlimited access
in the aftermath of haymaking
Infectious bovine rhinotracheitis (IBR) – A dairy herd in which
IBR is present may show reduced milk yield.

13. During respiratory diseases outbreaks
need to examine the following:
•Examination of the environment
•Observations at a distance
• General clinical examination
This should precede the examination of the respiratory system so that
major clinical signs of other body regions and systems can be detected.
In some outbreaks all the animals in the group have their
temperatures taken to identify grossly normal but pyrexic animals for
early treatment.

14. •Abnormal breathing
•Audible abnormal respiratory sounds
including the following:
Coughing
Sneezing
Upper airway noise
Expiratory grunting

15. Physical examination
Physical examination of the
thorax includes
•palpation,
•auscultation
•percussion.

16. cise, excitement) or due to pathological states (e.g.
pyrexia, pneumonia with lung consolidation). Loud-
er or abnormal sounds are produced by increased
air velocity through narrowed airways. Sound is
transmitted more efficiently by denser material, and
louder breath sounds can be caused by an increase
in the density of the tissue through which the
sound is being transmitted. Pneumonia with lung
consolidation and atelectasis are examples.
Abnormal inspiratory soundsThese indicate
upper airways abnormalities. In conditions which
cause narrowing of the upper airways, such as a
retropharyngeal abscess or laryngeal calf diphtheria,
abnormal respiratory sounds such as stridormay
be heard on inspiration. This noise may radiate
throughout the trachea and the lung fields. It is pro-
duced by an increase in the airflow velocity through
the narrowed upper airway. Narrowing of the air-
way is most pronounced on inspiration because of
the lower pressure in the trachea at this stage of the
respiratory cycle. During expiration there is a higher
positive pressure in the airway which tends to open
it up.
Abnormal expiratory soundsThese indicate lower
airway abnormalities. In conditions which cause
narrowing of the lower airways within the thorax,
such as bronchopneumonia, the breath sounds are
louder during expiration and quieter during inspira-
tion. During inspiration, the diameter of lower air-
ways within the thorax is increased by the outward
movement of the chest wall and decreased during
expiration by compression of the chest. The airflow
velocity is therefore greatest during expiration.
In cattle with tachypnoea and hyperpnoea there is
an increase in the airflow velocity on both inspiration
and expiration, with an increase in the loudness of
both sounds.
Decreased loudness of breath soundsThe reasons
may be physiological (e.g. a very fat animal) or
pathological (e.g. pleural effusion, pneumothorax,
space-occupying lesions). These conditions insulate
CHAPTER 7
72
Plastic rectal
glove
Elastic band
Figure 7.7Rebreathing bag can be used to increase the respiratory rate and to aid auscultation of the lung sounds.

17. Trachea
The trachea is readily identified by palpation of the tracheal
rings as it passes down the ventral part of the neck. The
trachea is not normally compressible unless some damage to
the integrity of the tracheal rings has been sustained. Palpation
of the trachea may occasionally provoke a single cough in a
normal animal. In cases of upper respiratory infection and
muscles of the neck. Stiffness of the neck with re-
duced mobility can also be a sign of tetanus.
Swellings and scar tissue
Soft tissue swellings and scar tissue may be present if
injections have been given either into the muscles of
the neck or subcutaneously. Occasionally, subcuta-
neous nodules arranged linearly are palpable and
are associated with so called ‘skin TB’ – non-specific
Mycobacteriuminfection (Fig. 5.21).
Larynx
The larynx is firm and non-compressible to the touch.
If the laryngeal aditus is compromised by infection,
gentle external compression may produce vibration
or stertor. In cases of severe obstruction, stertorous
breathing may be present without palpating the
larynx. Auscultation of the larynx and trachea
reveals greatly increased sound levels in cases of la-
ryngeal obstruction. Increased referred lung sounds
may also be present in such cases. The greatest inten-
sity of sound is auscultated over the seat of obstruc-
tion in the larynx.
Pharyngeal cavity
The pharyngeal cavity lies dorsal to the larynx and
can be readily compressed manually unless the
retropharyngeal lymph nodes are infected and en-
larged. A large pharyngeal foreign body, such as a
potato, can sometimes be detected just dorsal to the
larynx by external palpation.
Trachea
The trachea is readily identified by palpation of the
tracheal rings as it passes down the ventral part of the
neck. The trachea is not normally compressible un-
less some damage to the integrity of the tracheal
rings has been sustained. Palpation of the trachea
may occasionally provoke a single cough in a normal
animal. In cases of upper respiratory infection and
Clinical Examination of the Head and Neck
47
Thumb occluding
jugular vein
Distended jugular vein
Auscultation of trachea
Larynx
Palpation/compression
of trachea
Lesions of ‘skin TB’
Enlarged
retropharyngeal
lymph nodes
Figure 5.21Lateral view of neck.

18. the sounds produced with a consequent reduction in
loudness.
Abnormal lower respiratory soundsThese include
clicking, popping or bubbling sounds, crackling
sounds, wheezes, pleuritic friction rubs and extrane-
ous noises. Clicking,poppingorbubbling sounds are as-
sociated with the presence of exudate and secretions
causing pressure fluctuations as the airway becomes
blocked and unblocked. Crackling soundsare associ-
ated with interstitial pulmonary emphysema (RSV,
fog fever, husk). Wheezesare continuous whistling
squeaking sounds due to narrowed airways. Pleur-
itic friction rubsproduce a high pitched squeak dur-
ing the respiratory cycle and indicate adhesions
or other pathological changes which increase the
friction between the the parietal and visceral pleurae.
These changes result in pain during respiratory
movements and may be accompanied by grunting.
Sometimes it is difficult to distinguish whether the
source of the abnormal rubbing sounds is pericardial
or pleural. The breathing sounds can be eliminated
by covering the nose for 15 seconds which will elimi-
nate the sound if it is pleural in origin but not if it is
pericardial. This is very easy to do in calves, but is
often impossible in adult cattle.
Some examples of lung pathology which may
cause abnormal lung sounds are shown in Fig. 7.8.
Percussion
In percussion the body surface is tapped. The
audible sounds produced vary with the density of the
tissue set in vibration.As with auscultation it is only
possible to percuss a portion of the lung region
because much of the anterior lung field is covered
by the forelimb.
There are four methods of percussionavailable.
(1)Tapping the thoracic wall with the fingers held
slightly flexed.This method is simple and easy
to perform and is illustrated in Fig. 7.9.
(2)Placing the fingers flat against the chest wall and
tapping the fingers with the fingers of the other hand
vigorously.This can be quite painful to the opera-
tor, particularly on a cold winter morning.
(3)Placing a flat oblong piece of plastic such as a plastic
ruler (the plexor) flat against the body wall and hitting
it with small rubber hammer or spoon (the plexi-
meter).This is a useful method, although it may
startle the animal at the beginning of the proce-
dure; it is illustrated in Fig. 7.9.
(4)Transthoracic percussion.One side of the chest, for
example the left side, is repeatedly percussed at
a single location over the left dorsal lung field
whilst the entire right lung field is systematically
auscultated. As the stethoscope is moved over
Clinical Examination of the Respiratory System
73
Consolidation Pleural
adhesions
Emphysematous
bullae
Purulent
material
Trachea
Narrowing
of the
bronchi
Figure 7.8Example of lung pathology which may cause
abnormal lung sounds.
Example of lung pathology which may
cause abnormal lung sounds.

19. Further investigations
Acomplete physical examination including auscul-
tation and percussion may be sufficient to charac-
terise respiratory disease. Sometimes additional
investigations may be helpful. The additional costs
must be considered carefully. Bronchoalveolar lavage
(BAL) is particularly helpful in cases of calf pneumo-
nia in which the identification of the aetiological
agent is required. Further investigations may in-
clude serology, nasopharyngeal swabs, sampling for
lungworm larvae, fibreoptic endoscopy, radiogra-
phy, ultrasonography, blood gas analysis, thoraco-
centesis and lung biopsy.
Bronchoalveolar lavage (BAL)
This is a simple technique and enables a bronchalve-
olar sample to be obtained which can be used for the
rapid identification of viral antigens by indirect
fluorescent antibody tests (IFAT), bacteriological
culture and cytology. Sampling of severely affected
animals should be avoided because of the added
stress caused by the procedure. New acute cases are
ideal. This technique is usually used when there has
been an outbreak of pneumonia with high morbidity
and vaccination programmes are being contem-
plated. In order to obtain an accurate profile of
the aetiological agent it is best to select up to five
animals for sampling.
Although this technique can be performed
through a fibreoptic endoscope, more rudimentary
equipment can successfully be used. The equipment
required is a 50 ml catheter tip syringe, disposable
gloves, a sterile 90 cm long flexible tube of small
(6 mm) diameter, 20 ml of warm sterile saline, viral
transport medium and topical local anaesthetic gel.
The technique is illustrated in Fig. 7.10. Local
anaesthetic gel is applied to the inner surface of a nos-
tril; 2 minutes are allowed for anaesthesia. The dis-
tances to the larynx and the base of the neck are both
measured and marked on the tube. The tube is gently
passed intranasally via the ventral meatus to the
larynx. Once the larynx is reached the tube is pushed
quickly forwards on inspiration to gain entry to the
trachea through the glottis. If successful, breathing
will be felt and heard at the end of the tube accom-
panied by some mild coughing. Getting the tube into
the trachea and not the oesophagus may require re-
peated attempts; if entry to the trachea has not been
successful the tube may have to be withdrawn a few
centimetres and advanced again. When it is in the
trachea, the tube is then advanced to the base of the
Clinical Examination of the Respiratory System
75
CLINICIAN’SCHECKLIST–THE
RESPIRATORYSYSTEM
History of the farm and patient
Observation at a distance
Identify the animals affected
At rest
Rising
Feeding
Exercise tolerance
Take temperatures of animals in group affected
Clinical signs observed
General clinical examination
Examination of the respiratory system
Upper or lower respiratory condition?
Severity of disease (pathophysiological assessment)
Breathing abnormalities
Palpation
Abnormal breath sounds on auscultation
Percussion
Further investigations
Aetiological agent
Bronchoalveolar lavage (BAL)
Paired serum samples
Nasal swabs
Faeces
Saliva
ELISA test for lungworm
Lesions
Ultrasonography
Radiography
Pathology
Lung biopsy
Thoracocentesis
Pathophysiology
Pulse oximetry
Acid/base blood gas analysis
Further investigations
Acomplete physical examination including auscul-
tation and percussion may be sufficient to charac-
terise respiratory disease. Sometimes additional
investigations may be helpful. The additional costs
must be considered carefully. Bronchoalveolar lavage
(BAL) is particularly helpful in cases of calf pneumo-
nia in which the identification of the aetiological
agent is required. Further investigations may in-
clude serology, nasopharyngeal swabs, sampling for
lungworm larvae, fibreoptic endoscopy, radiogra-
phy, ultrasonography, blood gas analysis, thoraco-
centesis and lung biopsy.
Bronchoalveolar lavage (BAL)
This is a simple technique and enables a bronchalve-
olar sample to be obtained which can be used for the
rapid identification of viral antigens by indirect
fluorescent antibody tests (IFAT), bacteriological
culture and cytology. Sampling of severely affected
animals should be avoided because of the added
stress caused by the procedure. New acute cases are
ideal. This technique is usually used when there has
been an outbreak of pneumonia with high morbidity
and vaccination programmes are being contem-
plated. In order to obtain an accurate profile of
the aetiological agent it is best to select up to five
animals for sampling.
Although this technique can be performed
through a fibreoptic endoscope, more rudimentary
equipment can successfully be used. The equipment
required is a 50 ml catheter tip syringe, disposable
gloves, a sterile 90 cm long flexible tube of small
(6 mm) diameter, 20 ml of warm sterile saline, viral
transport medium and topical local anaesthetic gel.
The technique is illustrated in Fig. 7.10. Local
anaesthetic gel is applied to the inner surface of a nos-
tril; 2 minutes are allowed for anaesthesia. The dis-
tances to the larynx and the base of the neck are both
measured and marked on the tube. The tube is gently
passed intranasally via the ventral meatus to the
larynx. Once the larynx is reached the tube is pushed
quickly forwards on inspiration to gain entry to the
trachea through the glottis. If successful, breathing
will be felt and heard at the end of the tube accom-
panied by some mild coughing. Getting the tube into
the trachea and not the oesophagus may require re-
peated attempts; if entry to the trachea has not been
successful the tube may have to be withdrawn a few
centimetres and advanced again. When it is in the
trachea, the tube is then advanced to the base of the
Clinical Examination of the Respiratory System
75
CLINICIAN’SCHECKLIST–THE
RESPIRATORYSYSTEM
History of the farm and patient
Observation at a distance
Identify the animals affected
At rest
Rising
Feeding
Exercise tolerance
Take temperatures of animals in group affected
Clinical signs observed
General clinical examination
Examination of the respiratory system
Upper or lower respiratory condition?
Severity of disease (pathophysiological assessment)
Breathing abnormalities
Palpation
Abnormal breath sounds on auscultation
Percussion
Further investigations
Aetiological agent
Bronchoalveolar lavage (BAL)
Paired serum samples
Nasal swabs
Faeces
Saliva
ELISA test for lungworm
Lesions
Ultrasonography
Radiography
Pathology
Lung biopsy
Thoracocentesis
Pathophysiology
Pulse oximetry
Acid/base blood gas analysis

20. neck until there is resistance: the tube is now at the
bifurcation of the major bronchi (the coryna) of the
trachea. The 50 ml catheter syringe containing 20 ml
of warm sterile saline is attached to the proximal end
of the tube and the saline is injected. Suction is imme-
diately applied to the syringe to withdraw as much of
the injected saline as possible. About 10 ml is usually
retrieved. Gross examination may reveal cellular
debris, suggesting inflammatory changes in the tra-
chea and bronchi, and occasionally lungworm larvae
may be observed.
Some of the refluxed saline should then be de-
canted into the viral transport medium and some
placed in a sterile tube for bacterial culture. Afurther
aliquot should be placed in EDTA for cytological ex-
amination. Analyses may include IFAT for PI3, RSV,
IBR and BVD, and bacterial culture for Pasteurella
andHaemophilus.
Amodification to the technique to avoid contami-
nation of the sample by nasopharyngeal commensels
is to place a short wider bore 8 mm tube through the
ventral meatus to the entrance of the glottis and feed
the 6 mm collection tube through the wider bore
tube, thus avoiding contamination of the collecting
tube.
Diagnosis of lungworm
Lungworm infestation is an important disease
affecting all ages of cattle.Examination of faeces, bron-
choalveolar samples and oral saliva samples for larvae may
confirm a diagnosis of lungworm. Exposure to lung-
worm can also be confirmed by an ELISA test on the
patient’s serum.
Acute and convalescent sera
Rising serological titres may give a retrospective in-
dication of the possible causal agent(s) of an outbreak
of viral pneumonia. Serological samples are taken
from five affected animals at the time of the outbreak
followed by repeat samples from the same animals
4–6 weeks later.A rising titre from weaned animals
indicates recent antigenic exposure.
Nasopharyngeal swab
Bronchoalveolar samples are better than nasopharyngeal
swabs in identifying the aetiological agents of pneumonia
in cattle, although nasophyrangeal swabs have been
used successfully to identify PI3 and IBR infections.
CHAPTER 7
76
Figure 7.10Bronchoalveolar lavage.

21. Diagnosis of lungworm
Lungworm infestation is an important disease affecting all ages of cattle. Examination
of faeces, confirm a diagnosis of lungworm. Exposure to lung- worm can also be
confirmed by an ELISA test on the patient’s serum.
Acute and convalescent sera
Rising serological titres may give a retrospective in- dication of the possible causal
agent(s) of an outbreak of viral pneumonia. Serological samples are taken from five
affected animals at the time of the outbreak followed by repeat samples from the
same animals 4–6 weeks later. A rising titre from weaned animals indicates recent
antigenic exposure.
Nasopharyngeal swab
Bronchoalveolar samples are better than nasopharyngeal swabs in identifying the aetiological
agents of pneumonia in cattle, although nasophyrangeal swabs have been used
successfully to identify PI3 and IBR infections.Pasteurella isolates may be commensals.
Long- handled sterile swabs are used. Swabbing must be vigorous to obtain samples of
mucosal cells required for virus isolation. Early clinical cases are preferable. Material for
virus analysis from the swabs must be placed in viral transport medium.

22. Other tests
Fibreoptic endoscopy (Endoscopy)
Radiography
Ultrasonography
Blood gas analysis and packed cell
volume (PCV)
Lung biopsy
Thoracocentesis