The same techniques apply as for humans when performing CPR on a dog.
CPR can provide your dog's heart beat and his breathing until the dog can perform these functions on its own.
Performing CPR on a dog when heart and respiratory failure occurs after a trauma such as an electric shock, poison ingestion, or a car accident, may be the only way of saving his life.
Do not perform CPR on a dog that has a heartbeat. Nor should you perform artificial respiration on a dog that is already breathing unless the breaths are very unsteady and shallow. Check the dog's sides to see if the chest is rising and falling.
If there is no heart beat, some of the visible signs could be fully dilated pupils and cool, blue colored gums. Familiarise yourself with the normal pulse of your dog, it could help you to react more quickly if an emergency does arise.
If you are performing CPR on a dog, make sure he is muzzled because an unconscious dog may become aggressive when it regains consciousness. Sme sort of home made defice will suffice.
Put the dog in position on it's side and pull the head and neck forward. Pull the dog's tongue forward so it is not blocking the throat and make sure the mouth is clear. Close the dog's mouth and apply the muzzle. Hold the dog's mouth and lips closed. Apply the muzzle.
If there is still no pulse, inhale and put your mouth over the dog's nose, forming an airtight seal. Exhale and repeat 10 - 15 times per minute. Remove your mouth and apply heart massage between breaths. Place the heel of one hand over the dog's chest. Place the heel of your other hand on top of the other. Pump firmly and briskly. Hold each push for two counts and release for a count of one.
Continue the massage until the heartbeat returns. Continue artificial respiration until the dog begins to breathe on it's own. Continue CPR for about 15 minutes after which time revival is very unlikely.