Pulmonary hypertension occurs as a primary or secondary disorder of the pulmonary vasculature. Doppler echocardiography provides a noninvasive tool for the estimation of pulmonary arterial pressure when tricuspid regurgitation or pulmonic insufficiency is present. The cardiology database at Colorado State University was reviewed, and echocardiographic records from cases diagnosed with pulmonary hypertension were evaluated. Application of the modified Bernoulli equation to the maximal instantaneous velocity of a right-sided regurgitant jet provided evidence of pulmonary hypertension in 53 dogs over a 4-year period. Tricuspid regurgitant velocity Ն 2.8 m/second or pulmonic insufficiency velocity Ն 2.2 m/second was considered abnormal and indicative of pulmonary hypertension. Tricuspid regurgitant gradients in 51 dogs ranged from 32 to145 mm Hg (mean, 63.0 mm Hg; median, 57.0 mm Hg; 25th-75th percentiles, 45.2-76.5 mm Hg). Pulmonic insufficiency gradients in 8 dogs ranged from 20 to 100 mm Hg (mean, 59.5 mm Hg; median, 61.5 mm Hg; 25th-75th percentiles, 32.0-84.5 mm Hg). Affected dogs ranged in age from 2 months to 16 years. Clinical signs were characteristic of cardiopulmonary disease, but a relatively high frequency of syncope was noted (12 of 53 dogs, 23%). Pulmonary hypertension was probably due to increased pulmonary vascular resistance in 23 dogs, pulmonary overcirculation in 2 dogs, and pulmonary venous hypertension in 23 dogs. Five dogs lacked a clinically recognizable cardiopulmonary cause of pulmonary vascular disease. Our results suggest that pulmonary hypertension can occur as a complication of commonly encountered cardiopulmonary diseases, and that Doppler echocardiography can facilitate recognition of this condition.Key words: Bernoulli; Echocardiography; Hypoxia; Overcirculation; Regurgitation; Velocity. Pulmonary hypertension (PH) is a well-recognized clinical condition in human patients and occurs as a primary or secondary disease of the pulmonary vasculature. Primary or idiopathic PH is characterized by pathology in the tunica media of muscular pulmonary arteries and is described as a plexogenic pulmonary arteriopathy.1 PH also may occur secondary to abnormally high left atrial pressure, increased pulmonary blood flow, or increased pulmonary vascular resistance.2 Increased pulmonary vascular resistance can be caused by obstructive or obliterative diseases of the vasculature, arterial vasoconstriction, or chronic pulmonary parenchymal disease. In veterinary medicine, the most well-recognized cause of pulmonary hypertension is heartworm disease. Embolism of dead heartworms causes acute clinical signs of pulmonary arterial hypertension, and mechanical occlusion of large pulmonary arteries is followed by proliferative intimal changes that lead to irreversible structural damage to the vasculature and sustained pulmonary hypertension.3-5 Chronic parenchymal inflammation and fibrosis of the lung contribute to vascular dysfunction. 3,6 Mild PH also has been reported in dogs with left-sided heart failure c...

Strains of Cryptococcus spp appeared to have host specificity in dogs and cats. Differences in lesion distribution between geographic locations may reflect strain differences or referral bias. Antigen assays alone may not be sufficient for diagnosis of cryptococcosis in cats and dogs.

Background: Tracheobronchomalacia is diagnosed in people by documentation of a reduction in airway diameter during bronchoscopy. While tracheal collapse in the dog has been well described in the literature, little information is available on bronchomalacia in the dog.Hypotheses: Bronchomalacia is common in dogs with tracheal collapse, is associated with inflammatory airway disease, and is poorly documented radiographically.Animals: One hundred and fifteen dogs admitted for evaluation for respiratory disease and examined by bronchoscopy. Methods: Case-controlled, observational study. Dogs examined and having a bronchoscopic procedure performed by a single operator were separated into groups with and without visually identified airway collapse. Clinical parameters and bronchoalveolar lavage findings were compared between groups. Radiographs were reviewed in masked fashion to assess the sensitivity and specificity for detection of bronchomalacia.Results: Tracheobronchomalacia was documented in 50% of dogs examined, with tracheal collapse in 21% and bronchomalacia in 47%. In dogs with bronchomalacia, collapse of the right middle (59%) and left cranial (52%) lung lobes was identified most commonly. Dogs with bronchomalacia were significantly more likely to display normal airway cytology and to have mitral regurgitation and cardiomegaly than dogs without airway collapse (P o .05). Radiographs were insensitive for detection of airway collapse.Conclusions and Clinical Importance: Bronchomalacia was identified more commonly than tracheal collapse in this population of dogs, and documentation required bronchoscopy. This study could not confirm a role for airway inflammation in bronchomalacia, and further studies are required to determine the role of cardiomegaly in the disorder.

OBJECTIVE To describe vertebral left atrial size (VLAS), a quantitative method to estimate left atrial (LA) size radiographically, and to determine its diagnostic value for prediction of echocardiographic LA enlargement in dogs with myxomatous mitral valve disease (MMVD) of varying severity. DESIGN Prospective observational study. ANIMALS 103 client-owned dogs with a left-sided systolic murmur. PROCEDURES For each dog, 3-view thoracic radiographs were obtained within 24 hours of an echocardiographic examination. The VLAS was measured on right and left lateral thoracic radiographs and compared with the left atrium-to-aortic root ratio acquired from short-axis (LA:AoSx) and long-axis (LA:AoLx) echocardiographic images. Left atrial enlargement was defined as an LA:AoLx ≥ 2.6 or LA:AoSx ≥ 1.6. Dogs were allocated to 4 groups on the basis of MMVD severity. RESULTS Of the 103 dogs, 15, 40, 26, and 22 were assigned to the control (no echocardiographic abnormalities), stage B1 (hemodynamically irrelevant MMVD), B2 (hemodynamically relevant MMVD), and C-D (MMVD with congestive heart failure) groups, respectively. Median VLAS, LA:AoSx, and LA:AoLx for the stage B2 and C-D groups were significantly greater than the corresponding medians for the control and stage B1 groups. There was a moderate positive correlation between VLAS and both LA:AoSx and LA:AoLx. Receiver operating characteristic analyses revealed that a VLAS ≥ 2.3 vertebrae was a useful predictor of LA enlargement. Intraobserver and interobserver agreements for VLAS measurements were high. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated VLAS was a repeatable and useful radiographic measurement for prediction of LA enlargement in dogs with MMVD.

Pulmonary thromboembolism (PTE) occurs as a complication to a number of commonly encountered clinical diseases. Antemortem recognition of this life-threatening disorder is hampered by nonspecificity of clinical signs. This retrospective study was performed to analyze clinical features, laboratory findings, imaging abnormalities, and concurrent postmortem diagnoses in 29 dogs with confirmed pulmonary embolism. A variety of clinicopathologic and radiographic abnormalities were noted but there were no pathognomonic findings for PTE. Arterial blood gas analyses were performed in 15 (52%) of 29 dogs; 12 (80%) of 15 exhibited hypoxemia and 15 (100%) of 15 had increased alveolar-arterial oxygen gradients. Response to supplemental O2 was variable and did not correlate with the presence or absence of additional pulmonary pathology on postmortem. At postmortem, 25 (86%) of 29 dogs had grossly visible emboli, 17 (59%) of 29 dogs had multiple disease processes, and 16 (55%) of 29 dogs had additional pulmonary pathology. PTE was suspected antemortem in 11 (38%) of 29 dogs. In dogs with respiratory signs consistent with PTE, the condition was a differential diagnosis in 11 of 17 animals; all had diseases previously reported to be associated with PTE. Neoplasia, systemic bacterial disease, and immune-mediated hemolytic anemia were diagnosed most frequently.