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Chapter 6: Minimum Database: Spinal Surgery 65

Figure 6.7 Lateral radiograph of the thorax in a 1‐year‐old male
Newfoundland dog presented for progressive generalized weakness showing
evidence of megaesophagus.

trauma, or comorbidities that could increase the anesthetic or
surgical risk should also have thoracic radiographs performed as
part of the work‐up (Figure 6.7).
Some diseases such as multifocal or metastatic tumours, trauma,
or infectious diseases can affect the thorax and the spine concur-
rently. Thoracic radiographs are indicated in trauma patients to rule
out conditions such as pulmonary contusions, pneumothorax,
hemothorax, and diaphragmatic hernia. Thoracic radiographs are
Figure 6.6 Thromboelastograph analyzer. Source: Courtesy of Dr. Shauna often indicated even when the clinical signs are confined to the
Blois. neurological system (Figure 6.8).
Thoracic computed tomography (CT) is more sensitive than tho-
specific values have been shown to be predictive of surgical racic radiography in the screening and detection of pulmonary
bleeding [17,18]. More elaborate platelet function testing such as nodules in dogs with malignant neoplasia [25] (Figure 6.9).
thromboelastography (TEG) have been described and used in ani- However, radiographs are still considered the standard of care due
mals in research and the clinical setting. TEG is able to detect and to CT’s limited availability, higher cost, and requirement for general
continuously display changes in viscoelastic properties of the blood anesthesia. In addition, there is evidence that CT’s high sensitivity
as it clots, providing a more global evaluation of hemostasis in vivo could lead to a possible over‐interpretation and diagnosis of meta-
than occurs when components of coagulation are studied indepen- static disease [26].
dently. TEG traces can suggest the presence of normocoagulable, Thoracic radiographic examination must include a minimum
hypocoagulable, hypercoagulable, and secondary fibrinolytic states of two orthogonal views, although a three‐view thoracic exami-
(Figure 6.5) and are thought to be more predictive of surgical nation is becoming routine standard of care (Figure 6.10).
bleeding [24] (Figure 6.6). Recognition of radiographic abnormalities is based on a thorough
Other tests, such as fibrin–fibrinogen degradation products understanding of normal radiographic appearance. Evaluation of
(FDPs) and D‐dimer assays, can provide evidence of fibrinolysis each of the four basic anatomical regions is the basis for interpre-
and fibrinogenolysis, which are indicative of DIC, but those tests tation: (i) extrathoracic region including thoracic skeleton and
can also be positive in dogs with other conditions including soft tissues of the thoracic wall and diaphragm; (ii) pleural space;
neoplasia, immune‐mediated hemolytic anemia, pancreatitis, and (iii) pulmonary parenchyma; and (iv) mediastinum including
sepsis [15,20]. heart and great vessels [27]. Many radiographic abnormalities are
nonspecific and it can be difficult to differentiate between normal
and abnormal. Interpretation by an experienced radiologist is
Thoracic Radiographs extremely valuable.
Thoracic radiographs are one of the most commonly performed
radiographic examinations in small animal practice. Ideally, they
should be obtained as part of the MDB in all animals with spinal Abdominal Ultrasound
cord disorder, particularly in those older than 6 years and those Similar to thoracic radiographs, evaluation of the abdomen is
with cardiovascular and/or respiratory abnormalities. Any animal recommended when assessing for systemic conditions such as
with an increased suspicion for neoplasia, infectious disease, neoplasia, trauma, and infectious diseases that affect the spine