Agonal breathing in dogs is a term used to depict a dog gasping for air before dying. This form of "breathing" has been also referred to as "autoresuscitation."
Many dog owners are concerned when they notice their dog gasping before dying, but agonal breathing shouldn't be confused for a dog struggling to breathe as it happens in life considering that, what is really happening is that the dog is actually not really breathing.
Agonal breaths are therefore not bringing oxygen to the body as normal life-sustaining breathing does. So what's their purpose then?
Agonal breathing is the body's last-ditch attempt to bring oxygen to the organs. Although it's not effective, it's a natural, reflexive and primitive phenomenon developing from the ventilatory center located in the dog's brain stem.
Its primary function is to sort of "jump start" the body. It's basically the brain's last attempt to try to "save" the dog's life although fruitless.
A Closer Insight
What happens is that, once the dog's heart stops pumping, the brain fails to get the vital oxygen it needs. It therefore turns on a reflexive type of breathing which leads to these final gasps.
"Our heart, lungs and brain stem are essential to our survival, so the last ditch-effort for survival takes place in the chest and brain," explains Ginger Alvarez in the book: "The Hospice Walk."
Gasping is therefore a well-studied physiological event that takes place during death.
Typically, the gasps start with more intensity, and then they become gradually weaker and weaker ending in terminal apnea with complete cessation of breathing movements.
Not Happening Only in Dogs!
In humans, final gasps are quite normal and expected. Indeed, it's a rather common happening in hospice care.
Indeed, in human hospice care, agonal breathing may often prompt family members to call nurses and doctors to perform CPR, but hospital staff will discourage this.
This is because they know for a fact that doing so would be useless at this point and they therefore suggest the family focusing on holding the dying person's hand while talking to their loved one.