Introduction
This condition is an acquired or congenital obstruction to the caudal vena cava affecting venous return to the right side of the heart. The venous obstruction causes increased pressure within the liver allowing for fluid and protein to leak out of the hepatic sinusoids into the surrounding areas.
Signalment
Dogs: Young dogs under two years old; Male> female. There has been no reported cases in cats.
Clinical Signs
Clinical signs can be vague and similar to other disease but include ascites (with modified transudate), hepatomegaly, lethargy, abdominal distension and abdominal pain and anorexia.
Diagnosis
Blood tests may reveal elevated liver enymes and the presence of a stress leukogram. If ascites is present, examination of this will prove it to be a modified transudate. Radiography will show the presence of ascites and an enlarged Caudal Vena Cava. If an Electrocardiograph (ECG) is performed, this may demonstrate right atrial enlargement (Tall P waves). Echocardiography may show visualisation of an obstruction. Abdominal ultrasound will also demonstrate ascites, plus hepatomegaly and enlarged heaptic veins. Angiography can be used to visualise blood flow.
Treatment
Surgery is indicated for some cases,but is very risky. Medical treatment to provide supportive therapy, includes regular abdominocentesis, plus the use of drugs, furosemide (a diuretic) and enalapril, an ACE inhibitor.
Prognosis
Excellent with an experienced surgeon, but poor if only medical therapy is used.
References
Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company
Ettinger, S.J, Feldman, E.C. (2005) Textbook of Veterinary Internal Medicine (6th edition, volume 2)W.B. Saunders Company
Fossum, T. W. et. al. (2007) Small Animal Surgery (Third Edition) Mosby Elsevier
Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.