1.Assess the dog's condition by rolling them on their right side. Extend the top (left) front leg and check for a heartbeat by putting your head against the chest and listening (with large dogs) or by placing your fingers near the sternum (chest) of a small breed. If you cannot feel the heart beat, you need to start CPR as soon as possible.
2. Open the dog's mouth and remove anything blocking their throat or mouth: a piece of bone, wood, toys, food or anything else. Remove any excess mucous or saliva. Be careful, as the dog may make a reflexive movement and it's easy to get bitten during this procedure.
3. Pull the tongue forward and straighten their head and neck to create a direct passage for their airway. Do not try to perform artificial respiration if the dog's head is bent backwards or on a side as the respiratory track will be obstructed by the position.
4. Put your hand(s) around the dog's muzzle and keep it closed. Take in a breath of air, seal the dog's nose with your mouth and blow the air in both nostrils at the same time. Keep blowing only until the chest lifts take into consideration the size of the dog. Move away your mouth immediately, to allow the air to come out of the dog's lungs. The normal breathing rate for a dog is 15/20 breaths per minute.
5. Check for a pulse or to see if the dog starts breathing again. If you can't feel a pulse, start the CPR procedure immediately. You can check the pulse of large-size dogs by listening to their chest. For smaller dogs you can check the femoral artery. If their pupils are dilated and unresponsive to light, you must start CPR in conjunction with artificial respiration.
6. For large dogs, put your dog's spine against your knees and put one hand over the other at about the height of their 5th rib, approximately 1/3 up the body from the chest. Interlock the fingers of your second hand with the first and press down with a firm, constant and even movement. Press down and release. Compressions should be given at a rate of at least 100-120 per minute or 2 breaths then 15 compressions repeated without any pauses. For small breeds gently press in the same area with just the fingers of one hand or place one hand on each side of the dog in a chest position if CPR is being done by another person. Performing artificial resuscitation and CPR on dogs is very difficult and often unsuccessful, despite the best efforts of the rescuer. Always seek immediate emergency veterinary care and, if possible, perform CPR or artificial resuscitation on the way to the vet if someone is driving you there. If the dog is non responsive or their heart doesn't start beating again within five minutes, unfortunately, it's probably too late. If you are near a vet, you may want to continue for a few minutes more, but in general the chances of the dog surviving are low.