Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 7
Observations at a distance
Observations at a distance are very important in
respiratory disease to establish which animals in a
group may be affected and the severity of the condition.
Many respiratory disease clinical signs can be
detected by observation. The affected group should
first be observed at rest. Severely affected animals are
often recumbent with mouth breathing. The amount
of coughing and which individuals are coughing
should be noted. If the group is being fed, animals
slow at rising and not feeding are likely to be ill.
Moving slowly towards a recumbent resting group
stimulates the animals to stand. Animals slow to rise
can be noted and examined in detail. The exercise
tolerance of the animals can then be assessed by
driving them gently in a circular manner around the
house. Affected animals will have more pronounced
clinical signs, including coughing and respiratory
distress, following exertion.
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.
Abnormal breathing
Abnormal breathing may not be related to pulmonary
disease but may be in response to acid/base disorders,
cardiovascular disease, excitement, systemic
toxaemias, pain, neurological conditions or changes
in the oxygen-carrying capacity of the blood.
It is important to observe the rate, depth, character and
rhythm of respiration. As a result of hypoxia due to the
reduced capacity for pulmonary gaseous exchange,
breathing may become laboured (dyspnoeic) with
increased thoracic and abdominal wall movements.
There may be an increase in the rate of breathing
(tachypnoea). This can also occur with excitement,
pain and fear, as well as disease.
Increased effort on inspiration may suggest upper
airway obstruction. Increased expiratory effort, with
the possible accompaniment of a grunt, may indicate
severe lower respiratory disease. A reduction in
the respiratory rate (oligopnoea) can be caused by a
metabolic alkalosis. Acomplete absence of breathing
(apnoea) may occur in meningitis or severe acidosis,
and is episodic. An increase in the depth of breathing
(hyperpnoea) may accompany pulmonary disease,
metabolic acidosis or a toxaemic state. A decrease in
the depth of respiration may indicate thoracic or
anterior abdominal pain.
Thoracic asymmetry with restricted movements
on one side may indicate collapse or consolidation
of one lung. Predominantly thoracic breathing may
indicate abdominal pain (traumatic reticulitis, perforated
abomasal ulcer) or increased abdominal
pressure (bloat). Predominantly abdominal breathing
may indicate thoracic pain (pleuritis) or severe
pulmonary disease (severe pneumonia).
Audible abnormal respiratory sounds
Coughing
This may be non-productive and may indicate tracheal
irritation such as in IBR. Alternatively, coughing
may be productive resulting in the removal of
excess mucous, inflammatory products or foreign
material.
Sneezing
Sneezing is not common in cattle but can occur in
cases of allergic rhinitis.
Upper airway noise
Stridor heard on inspiration and caused by a reduction
in the cross-sectional area of the larynx is sometimes
heard in cases of laryngeal calf diphtheria. A
louder noise known as snoring may be heard with
retropharyngeal abscessation causing external pressure
on the larynx or upper airway.
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