Signalment, clinical features, echocardiographic findings, and outcome of dogs and cats with ventricular septal defects: 109 cases (1992-2013).

OBJECTIVE: To determine the signalment, clinical features, echocardiographic findings, and outcome of dogs and cats with ventricular septal defects (VSDs). DESIGN: Retrospective case series. ANIMALS: 56 dogs and 53 cats with VSDs. PROCEDURES: Medical records of dogs and cats with VSDs diagnosed by means of conventional and Doppler echocardiography were reviewed. Signalment, clinical status, echocardiographic findings, and outcome data were recorded. Variables of interest were analyzed for the study population and subgroups according to species and clinical status. RESULTS: VSDs were isolated (ie, solitary defects) in 53 of 109 (48.6%) patients. Most (82/109 [75.2%]) VSDs were membranous or perimembranous. Terriers and French Bulldogs were commonly represented canine breeds. Most isolated VSDs were subclinical (43/53 [81%]) and had a pulmonary-to-systemic flow ratio < 1. 5 (24/32 [75%]). The VSD diameter and VSD-to-aortic diameter ratio were significantly correlated with pulmonary-to-systemic flow ratio in dogs (r = 0.529 and r = 0.689, respectively) and in cats (r = 0.713 and r = 0.829, respectively). One dog underwent open surgical repair for an isolated VSD and was excluded from survival analysis. Of the remaining animals with isolated VSDs for which data were available (37/52 [71%]), no subclinically affected animals developed signs after initial diagnosis, and median age at death from all causes was 12 years. CONCLUSIONS AND CLINICAL RELEVANCE: Most dogs and cats with isolated VSDs had a long survival time; few had clinical signs at diagnosis, and none with follow-up developed clinical signs after diagnosis.

Quantification of pulmonary to systemic flow ratio by a Doppler echocardiographic method in the normal dog: Repeatability, reproducibility, and reference ranges.

OBJECTIVE: To determine if the pulmonary to systemic flow ratio (Qp/Qs) could be assessed in healthy awake dogs using Doppler echocardiography. BACKGROUND: Qp/Qs could provide reliable information in assessing the severity of intracardiac shunts (ICS) by quantifying pulmonary overcirculation. Qp/Qs has been validated against electromagnetic flowmeter methods in experimental canine models. However, its clinical applicability in awake dogs has never been assessed. ANIMALS, MATERIALS AND METHODS: Six healthy dogs were used to determine the repeatability and reproducibility of the technique (Study 1); Qp/Qs was then prospectively assessed in 50 healthy dogs (Study 2). In both studies Qp/Qs was calculated in awake animals using a standardized Doppler echocardiographic method. RESULTS: Within- and between-day coefficients of variation for Qp/Qs were <10% (Study 1). For Study 2, a relatively wide range of Qp/Qs was found (reference range=0.71-1.29; mean+/-SD=1.00+/-0.15). CONCLUSIONS: Qp/Qs can be assessed with good repeatability and reproducibility in healthy dogs. However, the wide range of Qp/Qs obtained in the healthy population may suggest a limited usefulness of this variable for accurately assessing ICS severity in diseased animals. This needs to be assessed in further prospective and longitudinal studies including a large number of animals with ICS of various grades.