Cardiac arrest or cardiopulmonary arrest or circulatory arrest refers to a condition when blood stops circulating due to the heart's inability to contract (heart failure). Since respiratory and cardiovascular systems work together, therefore, if a dog fails to breathe for more than six minutes, it can lead to heart failure and cardiac arrest. Both of these conditions can be fatal. Blood circulation may remain intact if the animal resumes breathing within four to six minutes, however if it lasts longer it can lead to cardiac arrest. Common symptoms include:
Dilated pupils
Loss of consciousness (syncope)
Cyanosis indicating low levels of oxtgen
Heavy and labored breathing and gasping for air (dyspnea)
Hypothermia
Lack of response to stimulation
