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Pet Euthanasia

Agonal Breathing in Dogs: What It Really Means for Your Pet

Losing a faithful canine companion is painful and can be scary. Especially when coupled with signs such as agonal breathing. What is agonal breathing and is it ... agonizing?

Dr. Bethany Hsia

May 07, 2023

The word agonal comes from the Greek word “agōn” which means “struggle” and is used because it can appear that the labored breaths are the animal struggling for air. However as we will discuss, the animal is not in agony while taking such breaths.

What Is Agonal Breathing in Dogs?

If you've already made the difficult decision to have your dog euthanized, your veterinarian may have discussed what to expect during the process. Occasionally at the end of their lives, our pets take deep, exaggerated, and irregular breaths which can be unsettling to say the least. However, at this stage of the euthanasia process the animal is no longer conscious.

As energy leaves the body on a cellular level, twitching of muscles, like the diaphragm, can be observed as irregular breaths. Additionally, reflexive breathing can occur as the respiratory system shuts down; it is important to note that these exaggerated breaths are merely a reflex, not a sign of pain or distress.

What To Expect With Agonal Breathing

In a euthanasia setting when agonal breathing occurs, it usually lasts a few minutes or less. Sometimes it is just a single deep breath, or it may also occur as several shorter rapid breaths. In an unassisted death when agonal breathing occurs it may last longer extending to several hours. On occasion it may include vocalization or noises like groaning as air passes over the vocal cords. It’s important to remember that agonal breathing occurs when the dog is not conscious and is not an expression of pain or anxiety.

When Does Agonal Breathing Occur?

Agonal breathing usually occurs as the respiratory system slows before shutting down. Because it is a reflex to lowering oxygen levels it is more likely to occur in pets who struggle with oxygenation already. These may be dogs with advanced heart disease, metastatic cancer to the lungs, pneumonia, severe anemia, tumors of the nasal passages or throat, laryngeal paralysis, stenotic nares, or any other compromise in their ability to oxygenate properly.

Additionally, it is seen more often in dogs who are experiencing an unassisted death rather than hospice or euthanasia patients. This is because many medications used in these scenarios can prevent muscle twitching and also because the euthanasia process occurs more quickly than natural death, decreasing the opportunity for reflexive breathing.

Here To Help You Navigate

Hopefully you feel more confident now, knowing more about what agonal breathing is and when it occurs. While it doesn’t happen in a majority of cases, it can be disturbing if it isn’t expected or understood.

If you are approaching the end of your dog’s journey, we would love to offer further empowerment and encouragement as you navigate this. Check out our other articles on assessing quality of life, understanding what end-of-life services are available, and preparing your dog for euthanasia. Finally, whether it be family, friends, your veterinarian, online resources, or support groups, know that you don't have to face this season by yourself.


Dr. Bethany graduated from the University of Illinois College of Veterinary Medicine in 2010. After graduation, she moved west. Dr. Bethany spent a year at a small animal exclusive practice in Washington state, where she was first introduced to in-home euthanasia.  Read More