Hyperadrenocorticism in dogs or Cushing’s disease is a serious condition that affects multiple organs. It has the potential of causing serious and complex medical conditions like heart failure, inflammation of the pancreas, and kidney related disorders like diabetes.
Cushing’s disease in dogs weakens the muscles, including the heart muscles that are required to pump blood to various parts of the body. In such conditions, synthetic epinephrine is used to induce controlled contractions in the heart muscles to resuscitate and resume heart functions.
In a healthy dog, epinephrine is secreted naturally by the adrenal medulla in response to stress. It stimulates the part of nervous system that controls involuntary actions. When secreted, it enters the blood stream and prepares the body to take action in emergencies. Generally speaking, epinephrine is what makes an individual either fight or take flight in the face of danger. It is what induces reflex actions, such as closing eyes in bright light or dodging a fist coming toward the face.
Epinephrine affects body functions in various ways:
- Increases heart rate and stroke volume
- Dilates pupils
- Contracts arterioles (small thin-walled arteries that end in capillaries) in the stomach and skin
- Dilates arterioles in the leg muscles
- Raises blood sugar levels
- Represses the immune system
Epinephrine was synthesized in the early 20th Century. Due to its properties of stimulation, it has been used as a drug for conditions like cardiac arrest and arrhythmia, asthma, and allergies. Although it helps in sending blood to the essential organs in the body, the accompanying increase in cardiac petulance is an important damaging effect. There have been a lot of private as well as governmental research and studies done on the subject of harmful effects of increased levels of epinephrine. The results remain inconclusive in many cases.
Natural epinephrine levels in dogs are affected when he is subjected to intravenous or inhalation (halothane) anesthetic drugs or epidurals. Synthetic epinephrine is also administered in dogs that suffer from heart related conditions due to other conditions like Cushing’s disease.