Page 571 - Problem-Based Feline Medicine

25 – THE CAT WITH POLYCYTHEMIA 563

which is an idiopathic inflammatory condition causing
Treatment
a combination of bronchoconstriction, chronic airway
inflammation and excessive mucus production. Treatment of respiratory conditions is dependent on the
Parasitic pulmonary disease such as lungworm or heart- correct diagnosis of the cause of the respiratory con-
worm may also cause chronic respiratory signs with dition, using a thorough diagnostic work-up proce-
intermittent hypoxia. dure.
Specific therapies are needed to treat respiratory
Clinical signs infections.

Coughing, intermittent dyspnea and hypoxia (oxy- Symptomatic medical therapy is recommended for
gen saturation <92%) are the most common clinical chronic inflammatory pulmonary disease such as
signs of chronic feline respiratory disease. Dyspnea feline asthma/bronchitis complex. Oral corticosteroid
may be acute, chronic or intermittent. therapy at anti-inflammatory dose rates and bron-
chodilators such as terbutaline or aminophylline may
There may be open-mouth breathing and cyanosis in
reduce the severity and frequency of dyspneic episodes.
severely affected cats.
Inhaled corticosteroid and/or bronchodilator therapy
Crackles and wheezes from bronchial disease and/or can be administered using pediatric asthma inhalers.
pleural effusion may be heard on thoracic auscultation.
Prognosis
Diagnosis
The prognosis for feline respiratory disease is good
Chronic pulmonary disease presents with auscultatory for most respiratory infections, although chronic
abnormalities, together with a history of intermittent infections may result in chronic inflammatory dis-
or continuous dyspnea and often chronic coughing. ease even after successful treatment of the infection.
Thoracic radiology reveals characteristic lung pat-
terns associated with bronchial, pleural or pul- POLYCYTHEMIA VERA*
monary disease.
Classical signs
Bronchoalveolar lavage cytology and microbiology
is useful in the diagnosis of inflammatory or bacterial ● Injected dark pink mucous membranes.
(e.g. Mycoplasma felis) lung disease. ● ± History of intermittent bleeding
diatheses.
Fecal flotation and examination should be performed
● ± Systolic ejection (hemic) murmur.
to check for parasites such as lungworm
● ± Central nervous system signs, such as
(Aleurostrongylus abstrusus).
seizures.
Serology should also be performed to detect heart- ● PCV > 60% with low serum erythropoietin
worm (Dirofilaria immitis) infection in endemic areas, concentration and normal blood O
as clinical signs of feline heartworm disease are gener- saturation. 2
ally respiratory in nature.
Toxoplasma serology may be performed as the lungs
are a common site for the extra-intestinal (tissue) phase Pathogenesis
of the disease.
Polycythemia vera results from an absolute increase in
red cell mass because of a clonal proliferation of neo-
plastic erythroid stem cells in the bone marrow asso-
Differential diagnosis
ciated with myeloproliferative disease.
Other causes of chronic hypoxia, such as congenital ● Erythroid precursors proliferate independent of
or degenerative cardiac disease, should be differenti- erythropoietin in a normal orderly pattern of matu-
ated from hypoxia caused by chronic pulmonary disease. ration.