No abstract

Canine ultrasonographic intestinal layers have been reported to correlate with histological layering. However, discrepancies have been reported in people, and additional layers visualized. The aim of this method comparison study was to describe ex vivo canine small intestinal layering and correlate it with histology. Small intestinal samples of 12 adult dogs euthanized for reasons unrelated to gastrointestinal disease were resected immediately following euthanasia, pinned on a Petri dish, and transverse ultrasonographic images acquired in a water bath, using a high-frequency linear transducer. Transverse histological sections were obtained at the same level. Measurements of the intestinal layers were performed on the ultrasonographic and histological images. No significant statistical differences were noted between the ultrasonographic and histological measurements and strong to very strong (r > 0.7) positive correlation was observed for all layers, except for the serosa, which had a low moderate positive correlation (r = 0.479). In addition to the five established layers, a dual mucosal echogenicity was consistently observed, with seven samples presenting an additional inner mucosal severe hyperechogenicity. Histologically, this dual echogenicity was attributed to the intestinal villi (mildly echogenic) and lamina propria (hypoechoic). The additional inner mucosal severe hyperechogenicity observed in seven samples was attributed to mild-to-moderate lacteal dilation histologically. In 4/12 ileal samples, an additional hyperechoic mucosal line was also observed parallel to the submucosa, corresponding histologically to prominent Peyer's patches. Finally, a hyperechoic line was observed within the muscularis of all samples, corresponding histologically to the interface between the muscularis longitudinal and circular layers.

Indicators of pulmonary hypertension in dogs examined with thoracic computed tomography (CT) are not well established in the veterinary literature. In humans, the main pulmonary artery to aortic diameter ratio (MPA:Ao) measured via CT, has been shown to be more sensitive than echocardiographic variables for predicting presence and severity of pulmonary hypertension, in some cases. In veterinary literature, the MPA:Ao has been determined echocardiographically to have an upper limit of about 1:1. Measurement of this ratio has not been described in dogs using CT. The objectives of this cross-sectional, prospective study were to compare echocardiographic measurement of MPA:Ao with that obtained via CT, determine if measurement of MPA:Ao via CT is repeatable and reproducible, and determine the effect of respiration and contrast administration on the measurement of MPA:Ao via CT. Ten healthy dogs without pulmonary hypertension were anesthetized to undergo thoracic CT using three protocols and echocardiography. The MPA:Ao was measured three times by three observers for each of the three CT protocols and compared to echocardiographic measurements. The mean MPA:Ao measured among all observers and CT protocols was 1.108 ± 0.152 (SD). The effect of CT scan protocol on MPA:Ao significantly differed among the three methods (P = 0.0014), where expiratory scans had lower MPA:Ao than inspiratory scans. The ratio measured on inspiratory CT scans consistently overestimated MPA:Ao when compared to echocardiography (bias = 0.226). Findings did not support the echocardiographically derived upper limit of MPA:Ao as an upper limit for determination of main pulmonary arterial enlargement on CT.

No abstract

Dogs presenting for ultrasonography due to suspected gastrointestinal disease might have residual ingesta and this could have an affect on the appearance of intestinal mucosa unrelated to pathology. The purpose of this prospective descriptive study was to determine effects of a recent meal consisting of the recommended daily fat content (meal 1) and a higher fat one (meal 2) on mucosal echogenicity in healthy dogs. Sixty client-owned and clinically healthy dogs were recruited. Two meals, one with 15% fat dry matter basis (meal 1) and a second with 1.5 ml/kg body weight corn oil added to result in a range of 41-63% fat dry matter basis (meal 2), were fed 1 week apart after a 12 h fast. Mucosal echogenicity scores were assigned at fasting, immediate postprandial and at 60 min after each meal. Duodenal scores were significantly greater for meal 1 at 60 min (P < 0.001) as opposed to fasting and immediate postprandial. With meal 2, the duodenal score was significantly different (P < 0.001) at the immediate and 60-min data point compared to meal 1. Jejunal scores were significantly greater for meal 1 at the 60-min data point (P < 0.001) as opposed to fasting and immediate postprandial. With meal 2, the jejunal score was significantly different (P < 0.001) only at the 60-min data point compared to meal 1. Intestinal mucosal echogenicity can be increased in healthy dogs after food intake, regardless of fat content. This effect should be taken into consideration when increased mucosal echogenicity is identified in clinical patients.