Page 634 - Problem-Based Feline Medicine

626 PART 9 CAT WITH SIGNS OF GASTROINTESTINAL TRACT DISEASE

ment of a fibrous tract and a communication devel- Treatment
ops between the esophagus and the respiratory system.
The only treatment is surgical closure of the fistula
The most common pathway in cats is between the and correction of the underlying cause if it is still
left caudal lung lobe or the accessory lung lobe and present (e.g. diverticulum, neoplasia).
the esophagus.
In some cats, lobectomy may be necessary as well.
The most common cause of fistula development is an
Symptomatic therapy for the pneumonia and
esophageal foreign body that penetrates (e.g. needle)
esophageal disease includes: esophageal rest (nasogas-
but other causes include diverticular structures and
tric or gastrostomy tube), antibiotic and bronchodila-
neoplasia.
tor therapy as needed, and drugs to control esophagitis
if it is present (e.g. ranitidine, metoclopramide, sucral-
Clinical signs fate, etc).
Signs are referrable to both the esophagus and lower
respiratory tract. Prognosis
Signs of esophageal disease include regurgitation, Guarded. Any esophageal disease that requires surgi-
painful swallowing or repeated swallowing attempts. cal correction must be regarded as having a guarded
prognosis because of the high rate of complications that
The majority of signs are respiratory, and include
occur following surgery (e.g. stricture).
dyspnea, coughing, tachypnea, anorexia, fever and
weight loss, associated with the accumulation of
esophageal contents in the affected lung lobe. Prevention
The smaller the fistula, the fewer the clinical signs Rapid identification and correction (removal) of
and the more difficult it is to diagnose. esophageal foreign bodies, diverticular structures or
neoplasia (if possible).
Diagnosis
A large fistula may be visualized on survey radio-
graphs, as well as the pulmonary changes associ- HEREDITARY MYOPATHY OF DEVON REX
ated with pneumonia (increased alveolar and interstitial CATS
pattern).
Classical signs
In cats with a very small fistula, contrast radi-
ographs may be required to identify the structure. In ● Young Devon Rex cats.
some cases, these may be so small that endoscopy is ● Appendicular weakness and fatigability.
not a means of definitive diagnosis either. ● Passive ventroflexion of the head and neck.
● Dorsal protrusion of the scapulae.
Endoscopic examination should be performed to
● Megaesophagus is common, and
obtain biopsies to determine if the lesion is neoplas-
choking and laryngospasm may occur
tic or not.
when eating.
If there is significant pulmonary disease, the cat may
have an inflammatory leukogram. See main reference on page 900 (The Cat With Neck
Ventroflexion) for details.
Differential diagnosis
Pathogenesis
Diverticular structures, esophageal strictures, radiolucent
esophageal foreign objects, and aspiration pneumonia The disease is inherited in an autosomal recessive
secondary to esophageal hypomotility, should all be con- fashion. The pathological defect causing the muscle
sidered when a differential list is being formulated. weakness has not been determined.