Page 65 - Problem-Based Feline Medicine

5 – THE DYSPNEIC OR TACHYPNEIC CAT 57

associated with lymphatic lymphangiectasia, although ● Bone marrow biopsy may be indicated if there is
cardiac disease and trauma need to be excluded. History, evidence of anemia of longer than 4–6 days duration
signs (evidence of murmurs, gallops and arrhythmias), without a regenerative response.
radiography and ultrasound help to differentiate these ● Measurement of carboxyhemoglobin concentration
causes from thoracic neoplasia. is required for diagnosis of CO toxicity. Routine
STAT assays are available in human hospitals.
Treatment
ACQUIRED OR CONGENITAL
Lymphoma of the thymus or mediastinal lymph
DIAPHRAGMATIC DEFECTS*
nodes is best handled with standard chemotherapy pro-
tocols for lymphoma (see page 676).
Classical signs
Surgical excision is the treatment of choice for thy-
● May or may not have clinical signs.
moma, and may be curative.
● Muffled heart and/or lung sounds.
Mesothelioma is an infiltrative disease that cannot be ● Occasionally dyspnea, cyanosis.
readily resected, and there are few reports in the litera- ● Vague gastrointestinal signs, gaunt
ture of effective chemotherapy. Local infusion of car- abdomen on palpation.
boplatin may be helpful with or without intravenous
doxirubicin. Prognosis is grave.
Clinical signs

Diaphragmatic hernia may occur as a congenital
ANEMIA/HYPOXEMIA* defect allowing abdominal organs to move into the
thoracic space or pericardium, or may follow trauma,
Classical signs especially a motor-car accident or fall from a
● Dyspnea, tachypnea and tachycardia. building.
● Pallor from anemia, cyanosis with With congenital hernias, signs may be evident as a kit-
methemoglobinemia. ten or there may be no signs until later in life, depend-
ing on the severity of the hernia.
Clinical signs With aquired hernias, signs may or may not be evident
Signs may be acute or chronic in onset depending on immediately following trauma, and worsen or
the underlying disease process. improve as adhesions form to limit movement of vis-
cera. In some cats, signs are only present with activity
Pale mucous membranes, tachycardia and tachyp- or stress.
nea occur with anemia.
Typically there are muffled heart and lung sounds, and
Cyanosis occurs with methemoglobinemia. occasionally borborygmus is audible in the chest.
Cherry red mucous membranes occur with carboxy- The severity of dyspnea is variable from mild, to acute
hemoglobinemia from carbon monoxide (CO) toxicity. and severe. Sudden worsening of signs may occur when
more abdominal viscera move into the chest.
Diagnosis Tachypnea, orthopnea (worsened dyspnea in lateral
recumbency) and cyanosis may occur depending on the
Diagnosis of anemia is based on finding a decreased
volume of abdominal organs in the thorax.
hematocrit on CBC.
● PCV < 10% may be associated with dyspnea, espe- On palpation, the abdomen has a gaunt or empty feel.
cially if the cat is stressed. Other ventral midline defects such as umbilical her-
● Evidence of blood loss or poor RBC production nias, pectus excavatum, etc., may be present with con-
may be evident. genital hernias.