Page 97 - Problem-Based Feline Medicine

6 – THE CAT WITH HYDROTHORAX 89

Clinical signs Hypoalbuminemia (< 15 g/L) is a persistent finding.
● Protein-losing enteropathy (PLE) has panhypopro-
Protein-losing enteropathy, protein-losing nephropa-
teinemia as the hallmark (hypoalbuminemia, globu-
thy and hepatic failure are common causes of low serum
lin < 20 g/L) (see page 760, The Cat With Signs of
protein, specifically hypoalbuminemia, which may result
Chronic Small Bowel Diarrhea).
in decreased oncotic pressure and transudation.
● Protein-losing nephropathy (PLN) is characterized
Signs are related to pleural effusion, ascites and muscle by proteinuria, urine protein:creatinine ratio > 2,
loss. hypoalbuminemia, possible hypertension and
hypercholesterolemia (nephrotic syndrome) (see
Orthopnea, tachypnea, minimal airflow with increased
page 358, The Thin, Inappetent Cat).
chest excursions, muffled heart and lung sounds may be
● Hepatic failure may be characterized by low urea,
present if the pleural effusion volume is > 50 ml/kg.
hypoalbuminemia, low to elevated cholesterol,
Weight loss with prominent muscle wasting is com- possible hypoglycemia, normal to low liver
mon. Distention of the abdomen from weakness of enzyme levels, elevated serum bilirubin levels
abdominal muscles, as well as presence of ascites may may be present (see page 421, The Yellow Cat or
be present. Hair coat is typically poor quality. Cat With Elevated Liver Enzymes).
Appetite may be ravenous in protein-losing enteropathy,
and diarrhea and weight loss are evident. Differential diagnosis
Rarely, signs of hepatic encephalopathy including Once hypoalbuminemia has been established and the
ptyalism, dementia, somnolence and pica occur with pleural effusion has been characterized as a pure tran-
liver failure. sudate, a general biochemistry panel will help to dis-
tinguish the major causes of hypoproteinemia.
Icterus may be present.
Treatment
Diagnosis Thoracostomy tube placement is generally not indicated.

Thoracic radiography demonstrates signs of pleural Treatment for the underlying disorders will be covered in
effusion, indistinguishable from other causes. the chapters for those conditions. If serum albumin can
● Thoracocentesis reveals a clear and colorless fluid, be increased above 15–20 g/L with treatment of the
which is a pure transudate with a specific gravity underlying disease, the hydrothorax and ascites will
(SG) < 1.013, low total protein (TP) < 2.5 g/L, and resolve providing there is not underlying hypertension or
9
low cellularity (TNCC < 1.5 × 10 /L). vasculitis.

RECOMMENDED READING
Bauer T, Woodfield JA. Mediastinal, pleural, and extrapleural diseases. In: Ettinger SJ (ed) Textbook of Veterinary
th
Internal Medicine, 4 edition. Philadelphia, Saunders, 1995, pp 817–822.
Lehmkuhl LB, Smith FWK. Pleural effusion. In: Tilley LP, Smith FWK (eds) The 5 Minute Veterinary Consult, 2 nd
edition. Baltimore, Lippincott, Williams & Wilkins, 2000, pp 1084–1085.
Padrid PA. Pulmonary diagnostics. In: August JR (ed) Consultations in Feline Internal Medicine 3. Philadelphia,
Saunders, 1997, pp 292–302.