Pulmonary hypertension (PH) has been reported in dogs infected with Angiostrongylus vasorum. Moderate to severe PH was identified in a small portion of dogs, associated with shorter survival time in a retrospective study. Only mild PH was identified in experimentally infected dogs. The objective of this study was to determine the prevalence and severity of PH in dogs presented to a university clinic with A. vasorum infection and to describe associated echocardiographic changes in these dogs.

Dogs presented between November 2013 and February 2017 with confirmed A. vasorum infection based on positive Baermann coproscopy, Ag detection in blood, or PCR in BALF were retrospectively included. Diagnosis of PH was based solely on radiography (group 1) or plus echocardiography (group 2). In group 2, PH severity was determined by tricuspid regurgitation velocity (TRmax), pulmonic insufficiency velocity (PRmax). When no regurgitation was measurable, indirect signs of PH such as, right heart remodeling, main pulmonary artery dilation (PA/Ao), acceleration time to ejection time (AT/ET), tricuspid annular plane systolic excursion (TAPSE), and pulmonary vein diameter-to-pulmonary artery diameter ratio (PV/PA) were taken into account.

Thirty-six dogs were included (group 1: 16; group 2: 20). Median age at the time of diagnosis was 4.5 years (3 months to 10 years). Chronic cough, dyspnea, and exercise intolerance were the main clinical complaints.

In group 2, 40% of dogs (8/20) had severe PH, 7/8 displaying a right apical systolic heart murmur, and 3/8 being in right-sided congestive heart failure. Prevalence of moderate and severe PH in group 2 was 65% (13/20), two dogs displaying only indirect signs of PH. In these dogs, median TRmax and PRmax were respectively 4.65 m/s (3.93–6.28), and 2.75 m/s (2.03–3.73). Median AT/ET, PA/Ao, PV/PA were 0.295 (0.178–0.49), 1.05 (0.64–1.28), and 0.7 (0.4–1.3), respectively. Right ventricular dilation was observed in 11/13 dogs and was considered as severe in all dogs with severe PH. However, TAPSE was within confidence interval for all dogs.

In group 1, only 25% of dogs had evidence of PH with mild enlargement of pulmonary arteries. However, in group 2, two dogs with severe PH had normal pulmonary vasculature on x-ray, questioning the sensitivity of thoracic radiography for PH.

In conclusion, based on Doppler-echocardiography, the prevalence of moderate and severe PH in dogs naturally infected with A. vasorum seems more important than previously described. Systematic ultrasound scanning of dogs infected with A. vasorum is advised to evaluate presence and severity of PH.

Disclosures

No disclosures to report.