Page 560 - Problem-Based Feline Medicine

25. The cat with polycythemia

Jacquie Rand and Annette Litster

KEY SIGNS
● Increased red cell concentration in peripheral blood.
● Injected mucous membranes.

MECHANISM?
● Dehydration resulting from disease of many organs may produce relative polycythemia.
Polycythemia may be an appropriate physiological response to hypoxia caused by pulmonary
or cardiac disease. Alternatively, inappropriate polycythemia may be associated with renal
space-occupying masses or other visceral tumors. Inappropriate primary polycythemia results
from a rare myeloproliferative disorder, polycythemia vera.

WHERE?
● Gastrointestinal tract, renal or skin (burns) disease causing excessive fluid loss.
● Cardiac or respiratory disease causing chronic hypoxia.
● Renal (space-occupying masses) or visceral (neoplastic conditions) conditions associated with
inappropriate erythropoietin secretion.
Bone marrow associated with myeloproliferative disease.
WHAT?
● The most common cause of polycythemia is dehydration. Hyperthyroidism produces mild
polycythemia in many cats. Appropriate polycythemia associated with hypoxia from chronic
respiratory or cardiac disease is less common. Primary or secondary inappropriate
polycythemia is very rare.

QUICK REFERENCE SUMMARY
Diseases causing polycythemia

DEGENERATIVE
● Cardiac disease* (p 561)
Cardiac conditions such as cardiomyopathy which result in tissue hypoxia or cyanosis from
cardiac failure may stimulate increased erythropoietin production, resulting in increased red

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