Page 231 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery

History: Historical features include the known occurrence
of blunt abdominal trauma or the presence of other injuries
VetBooks.ir sionally, animals with chronic hernias are presented
that indicate a traumatic incident has occurred. Occa-
because of progressive exercise intolerance, difficulty
breathing or gastrointestinal disease, with no indication of
historical trauma other than a ruptured diaphragm.
Clinical signs: There are no pathognomonic signs of dia-
phragmatic rupture. The clinical signs reflect the extent
and severity of the pathophysiological changes outlined
above. In acute diaphragmatic rupture, respiratory signs
predominate, with dyspnoea, orthopnoea and exercise
intolerance present in at least 38% of cases (Stokhof,
1986). Some animals will adopt a sitting or standing posi-
tion with their elbows abducted and head and neck (a)
extended. Animals with pleural space disease usually
show a restrictive respiratory breathing pattern, that is,
rapid, shallow respiration. In animals with a chronic hernia,
gastrointestinal signs may predominate, such as vomiting,
diarrhoea, dysphagia and constipation. Other non-specific
signs include depression, anorexia, weight loss and diffi-
culty lying down (Stokhof, 1986).
Physical examination: The physical examination may appear
to be within normal limits in some individuals.
Palpation of the thorax may elicit pain (e.g. from frac-
tured ribs or bruising) and may reveal a shift of the apex
beat of the heart away from the side of the rupture. With
experience, thoracic palpation will identify the side of the
rupture in 80% of cases (Stokhof, 1986). The abdomen
may appear tucked-up and may appear empty on exami-
nation or palpation, although this is a subjective and
un reliable sign (Garson et al., 1980).
Percussion may reveal hyporesonance if fluid or abdom-
inal organs are present in the ipsilateral pleural space, and
hyper-resonance if either free air (e.g. pneumothorax) or
circumscribed air (e.g. gastric tympany) is present. (b)
On auscultation of the chest, the heart and lung
sounds may be muffled on the side with the rupture. With 17.12 Ruptured diaphragm. (a) Lateral view of the thorax. The
cardiac silhouette and lungs are obscured by an ill-defined
displacement of the heart, the apex beat may be auscul- heterogeneous soft tissue/fat/gas opacity representing small intestine,
tated in an abnormal location and the heart sounds colon and liver. The heart is displaced cranially and dorsally.
may be more intense on the side contralateral to the (b) Dorsoventral view of the thorax. The right hemithorax contains an
rupture. Auscultation of borborygmi within the chest is an ill-defined heterogeneous soft tissue/fat/gas opacity representing small
uncommon finding. intestine, colon and liver. The heart is displaced cranially and to the left.
Survey radiographs: Thoracic radiography is the most
useful screening test for the presence of diaphragmatic • Abdominal viscera within the thorax, e.g. liver, spleen,
rupture, with the lateral view the most useful single view stomach, intestine
(Sullivan and Lee, 1989). The DV view allows the side of • Displacement of abdominal structures, e.g. liver,
the rupture to be determined and is more sensitive for spleen, stomach, intestine
the detection of small amounts of pleural fluid. The radio- • Displacement of thoracic structures, e.g. heart,
graphs should also include the cranial abdomen. mediastinum, lung lobes
Although in ideal circumstances a full radiographic • Change in appearance of thoracic structures, e.g. lung
study would comprise a DV and one or two lateral views, lobe collapse
care must be taken not to cause the animal undue distress • Loss of demarcation of thoracic structures, e.g. heart
during restraint. The first radiographic view to be taken shadow
should be the one that causes least distress. Under no • Pleural fluid.
circumstances should a VD view be attempted in the dysp-
noeic animal or in a patient where a ruptured diaphragm or Abnormal intrathoracic structures may be identified as
other thoracic disease is suspected. abdominal in origin if their opacity is different (e.g. fat
Radiographic signs associated with diaphragmatic opacity of the falciform ligament, fat-containing omentum,
rupture (Park, 1994) (Figure 17.12) are: gas-filled bowel) or if their structure indicates an abdomi-
nal organ (e.g. gastric rugal folds, loops of small intestine).
• Partial or complete loss of the thoracic diaphragmatic If a diagnosis cannot be obtained from survey radio-
surface graphs then further procedures may be performed. The
• Cranial displacement or angulation of the simplest procedure should be chosen first. These addi-
diaphragmatic line tional procedures include:

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