When performing CPR on a dog, the ratio of compressions to breaths should be 5:1. For every five chest compression; you should give one breath. The chest compressions should be performed at a rate of 100-120 per minute, while the breaths should be given slowly and gently. It is essential to start with chest compressions before giving any breaths to keep blood circulating throughout the body. Cover the dog's nose and mouth entirely with your mouth or a barrier device such as a cloth or gauze when giving the breaths. You should provide two rescue breaths after each set of 30 chest compressions. If possible, it is best to have another person help during the CPR process by counting out loud and reminding you when it is time to switch from chest compressions to rescue breathing.