Objective—To quantitatively and qualitatively assess the radiographic appearance of the thorax of clinically normal alpaca crias. Animals—21 clinically normal alpaca crias. Procedures--Left-right lateral (LR), right-left lateral (RL), dorsoventral (DV), and ventrodorsal (VD) projections of the thorax were acquired. To account for differences in cria size, measurements of thoracic structures were compared with other anatomic landmarks. Results—Mean ± SD vertebral heart scale was 9.36 ± 0.65 for LR projections, 9.36 ± 0.59 for RL projections, 8.21 ± 0.51 for DV projections, and 8.65 ± 0.57 for VD projections. Dimensions of the heart were compared with the length of the T3 through T5 vertebral bodies, third to fifth rib distance, and thoracic height and width, which provided additional methods of cardiac evaluation. For RL projections, mean ratio of the right cranial pulmonary artery diameter to the third rib width was 0.41 ± 0.10 and mean ratio of the right cranial pulmonary vein to the third rib width was 0.44 ± 0.10. Caudal lobar pulmonary vessels and the caudal vena cava were difficult to quantitatively assess on DV or VD projections. On lateral projections, the trachea was increased in diameter at the origin of the right cranial lobar bronchus. No qualitative differences were found between LR and RL radiographs. The lungs were generally better inflated on VD projections, with more separation of the heart and diaphragm. Conclusions and Clinical Relevance—Establishment of radiographic values for alpaca crias should prove useful in assessment of thoracic disease in this species.

Objective—To determine the analgesic and systemic effects of thoracic epidural administration of ketamine, lidocaine, or both in conscious dogs. Animals—6 adult mixed-breed dogs. Procedures—Each dog received 2% lidocaine hydrochloride without epinephrine (3.8 mg/kg), 5% ketamine hydrochloride (3.0 mg/kg), or both in randomized order with = 1 week between treatments. Drugs were administered in a total volume of 0.25 mL/kg through a thoracic epidural catheter implanted via the lumbosacral approach. Heart rate, blood pressure, respiratory rate, rectal temperature, analgesia, sedation, and ataxia were determined before treatment (baseline [time 0]) and at 5, 10, 15, 20, 30, 40, 50, 60, 90, 120, 150, and 180 minutes after administration. Results—The main areas of analgesia for the 3 treatments were the thorax and forelimbs bilaterally. Median duration of analgesia was shorter after administration of ketamine (30 minutes) than after administration of lidocaine (40 minutes) and lidocaine plus ketamine (90 minutes). All treatments caused moderate motor blockade, and only the ketamine and lidocaine plus ketamine treatments caused mild sedation. Significant decreases in systolic and mean arterial blood pressure were observed only with the lidocaine plus ketamine treatment. Conclusions and Clinical Relevance—Thoracic epidural administration of lidocaine plus ketamine resulted in longer duration of analgesia of the thorax and forelimbs bilaterally in conscious dogs, compared with administration of ketamine or lidocaine alone. Additional studies are needed to determine whether this technique adequately relieves postoperative pain after thoracic surgical procedures and whether it causes respiratory depression in dogs.