Page 66 - Problem-Based Feline Medicine

58 PART 2 CAT WITH LOWER RESPIRATORY TRACT OR CARDIAC SIGNS

Intermittent vomiting and inappetence are the most Typically, there is acute onset of single limb paresis
common gastrointestinal signs. or paralysis, which most often involves the hindlimbs.
Signs may be bilateral with a “saddle thrombus” at the
Diagnosis aortic trifurcation.

Thoracic radiographs demonstrate bowel loops, or On physical examination the limb is cool and pulse-
space-occupying soft tissue densities within the pleural less, with cyanotic foot pads or nail beds. The gas-
or pericardial space. Globose cardiomegaly is evident trocnemius muscle is firm and painful on palpation.
with peritoneopericardial diaphragmatic hernia.
Signs of congestive heart failure including cyanosis,
Other imaging modalities such as ultrasonography, pos- respiratory distress, or evidence of pleural effusion may
itive contrast upper GI series, pneumoperitoneography be present. Dyspnea and tachypnea may be acutely
or contrast injected into the abdomen (celiogram) may exacerbated. Heart murmurs, arrhythmias and gallops
be useful for diagnosis. are often evident.

Differential diagnosis Diagnosis
Pleural space disease (effusions, pneumothorax, mass Diagnosis is based on the clinical signs and confirmed
lesions), pericardial effusion and cardiomyopathy may by evidence of lack of blood flow in the distal limb
have similar signalment and signs to traumatic measured by a Doppler flow meter.
diaphragmatic hernia, but can usually be differentiated
Thoracic radiography and ultrasonography
on radiography and ultrasonography.
demonstrate underlying heart disease, often with sig-
nificant chamber enlargement, especially of the left
Treatment atrium.
Treatment consists of surgical repair after stabilizing Contrast arteriography of the affected limb is the
the patient. If dyspnea is the major clinical sign, stabi- “gold standard”, but not frequently used in clinical
lization may not be possible until the pericardial or cases.
pleural cavities are evacuated. Oxygen therapy is of lit-
tle value in a patient with severe pleural occupation.
PULMONARY THROMBOEMBOLISM*

AORTIC THROMBOEMBOLISM* Classical signs
● Sudden onset of severe dyspnea with
Classical signs
normal lung parenchyma radiographically.
● Acute single or bilateral limb paresis or ● Peracute dyspnea, orthopnea, tachypnea.
paralysis, most often involving hindlimbs. ● Cyanosis, collapse.
● Signs of congestive heart failure – ● Cough, with or without hemoptysis.
cyanosis, respiratory distress, pleural
effusion.
● Heart murmurs, arrhythmias and gallops. Pathogenesis
Pulmonary thromboembolism involves embolic
See main reference on page 915 for details (The Weak showering of the pulmonary arterial tree, causing
and Ataxic Cat or Paralyzed Cat). obstruction of blood flow to that portion of the lung.

Clinical signs Thrombi may be produced locally (i.e., feline heart-
worm disease), or may embolize from distant locations.
Cardiomyopathy in cats is sometimes associated with Thrombi may originate in the right atrium (cardiomy-
thrombus formation in the left atrium. The thrombus may opathy, advanced tricuspid valvular disease), caudal
be dislodged, and most commonly obstructs the aorta at vena cava, femoral veins, mesenteric venous system or
its trifurcation (saddle thrombus). jugular veins.