Degree Type


Date of Award


Degree Name

Master of Science


Veterinary Clinical Sciences


Veterinary Clinical Science (Veterinary Medicine)

First Advisor

Jessica L. Ward


Thoracic ultrasound has proven effective for the diagnosis of left-sided congestive heart failure (L-CHF) dogs and cats with respiratory distress. The objective of this study was to determine whether ultrasonographic indices of the caudal vena cava (CVC) could be used to diagnose right-sided CHF (R-CHF) in dogs with cavitary effusions.

Dogs were prospectively enrolled in four groups: R-CHF (n = 34), L-CHF (39), cavitary effusions of noncardiac etiology (NC, 41), and pericardial effusion with tamponade (PCEFF, 17). Ultrasonographic indices included right ventricular to left ventricular ratio (RV:LV) and 2D and M-mode subxiphoid measures of CVC maximal and minimal size (CVCmax and CVCmin), CVCmax indexed to aortic dimension (CVC:Ao), and CVC collapsibility index (CVC-CI). Variables were compared between study groups using Kruskal-Wallis and Dunn's-Bonferroni testing.

All indices (RV:LV, CVCmax, CVCmin, CVC:Ao, and CVC-CI) were significantly different between R-CHF and NC dogs (p < 0.005). A CVC-CI less than 30% (in either M-mode or 2D) was 97% sensitive and 93% specific for diagnosis of R-CHF versus NC effusion. All CVC indices, but not RV:LV ratio, also differed between PCEFF and NC dogs (p < 0.005). Compared to NC, L-CHF dogs had higher CVC:Ao in both 2D (p = 0.017) and M-mode (p = 0.014); compared to R-CHF, L-CHF dogs had higher CVC-CI in both 2D and M-mode (p < 0.005).

Ultrasonographic indices of CVC size and collapsibility are useful to differentiate R-CHF versus NC disease as causes of cavitary effusions. Dogs with L-CHF demonstrate CVC measurements intermediate between R-CHF and NC dogs.


Copyright Owner

Yen-Yu Chou



File Format


File Size

23 pages