In order for the veterinarian to perform chest compressions during cardiopulmonary resuscitation, a dog should be positioned in which of the following positions?

For effective chest compressions during cardiopulmonary resuscitation (CPR) in a dog, the optimal position is lateral recumbency. In this position, the dog lies on its side, which allows for proper access to the chest area where compressions are performed. It is crucial to ensure that the person administering CPR can deliver compressions directly over the heart, which is located towards the left side of the chest in dogs.

When the dog is in lateral recumbency, the compressions can be administered more effectively, allowing for optimal blood flow to be maintained during the resuscitation effort. This positioning helps to create adequate pressure on the thoracic cavity, facilitating the return of blood to the heart and aiding in providing necessary oxygen and nutrients to vital organs.

Other positions, such as dorsal recumbency (lying on the back), may hinder effective compressions and create challenges in accessing the chest. Similarly, a sitting position or standing position do not provide the necessary access for effective compressions and could compromise the efficacy of the resuscitation effort. Therefore, lateral recumbency is the correct choice for performing chest compressions during CPR in dogs.