An 8-year-old castrated male Labrador Retriever was evaluated for severe trauma after being hit by a car. Injuries included subluxation at T12-13, thoracic trauma including a mild pneumothorax and pulmonary contusions, multiple lacerations, and a right brachial plexus avulsion. Additional thoracic radiographic views were obtained 11 days after the initial injury to evaluate placement of an esophageal feeding tube (Figure 1).
Right lateral and ventrodorsal radiographic views of the thorax of a dog that had been hit by a car 11 days earlier.
Determine whether additional imaging studies are required, or make your diagnosis from
Objective—To develop and assess the reproducibility of a protocol to noninvasively test endothelial function in dogs on the basis of the flow-mediated vasodilation (FMD) procedure used in humans.
Animals—5 healthy spayed female dogs.
Procedures—Luminal arterial diameter and blood flow velocity in the brachial and femoral arteries were measured with ultrasonography. The within-dog reproducibility of these ultrasonographic measurements was tested. An occlusion period of 1, 3, or 5 minutes with an inflatable cuff was used to create the FMD response. Measurements made at 15, 30, and 60 seconds following release of the occlusion were compared with measurements made immediately prior to each occlusion to assess the FMD response.
Results—Within-dog reproducibility of measurements revealed moderate to high correlations. Change from baseline in luminal arterial diameter was most substantial when measured at 30 seconds following release of occlusion, whereas blood flow velocity changes were maximal when measured at 15 seconds following release. The brachial imaging site provided a larger number of significant FMD responses than the femoral site. The 3-minute occlusion period provided equal or better responses than the 5-minute occlusion period.
Conclusions and Clinical Relevance—Ultrasonographic measurement of the FMD responses was a feasible and reproducible technique and significant changes from baseline were detected. The FMD responses in dogs were most substantial when performed at the brachial artery with blood flow velocity and luminal arterial diameter changes from baseline measured at 15 and 30 seconds, respectively, following release of a 3-minute occlusion period.