If the dog is NOT breathing but DOES have a pulse, you need to perform artificial respiration. Artificial respiration is NOT the same as CPR (CPR is compressions on the heart AND breaths), artificial respiration is just breathing for a dog who still has a heartbeat as follows:
1) Lay the dog on his right side with his back towards you, legs pointing away.
2) Extend the neck and tilt the head backwards.
3) Pull the tongue forward so that it sticks out of the mouth.
4) Hold the muzzle, “clamping” the tongue between the teeth.
5) Breathe 5 breaths down the nostrils
(NB. for small breeds you should put the whole of the muzzle in your mouth & breathe gently to avoid doing any damage to the lungs)
6) Watch the chest rise as you blow, take your face away from the dog’s muzzle and watch as the chest falls again before your next breath (do this 5 times in total)
After the 5th breath, commence manual respiration as follows:
1) With the dog in the same position, place your flat palms over his ribs and push down about 1/3 of the depth of the chest – we are NOT aiming for the heart, but merely to squash the air from the lungs (N.B. for small breeds, one had may be enough)
2) Remove your hands and count to 5 as you allow the ribs to spring back to their usual position, the lungs to re-inflate and the chest to rise.
3) Continue by rhythmically pushing the chest down, removing your hands and then counting to 5, repeatedly for about 1 minute.
4) Check to see if the dog has commenced breathing for himself/still has a pulse
5) If he still has a pulse but is not yet breathing for himself, continue pushing down on the chest & counting to 5 for another 20 minutes, checking every 2-3 minutes to see if there has been any signs of recovery.
6) If he does not have a pulse by the time you check, commence CPR.
Below is a link to a video from You Tube which shows Artificial Respiration in action. Although it’s not executed in a perfect “text-book” style, it certainly does give you a very good idea of what you should be doing and how the procedure works. Please note, this is a very harrowing video to watch but, as there IS happy outcome, I think it’s certainly worth watching to help you understand.