There are dozens of causes for a cat to lose consciousness, and all of them are potentially serious and life-threatening. Syncope is most often associated with cardiovascular disease, while coma can be caused by a number of underlying diseases and is very grave. In general, syncope cannot be prevented unless the precipitating event can be avoided.
A wide range of conditions can lead to loss of consciousness.
Pressure on the neck or collar can cause syncope in some animals, such as those with hypersensitive carotid sinus syndrome.
Unconsciousness varies in the degree to which the animal is unresponsive to its environment, as well as in duration of episode. Syncope is usually short-lived with complete and rapid recovery, while coma is persistent until the underlying cause can be treated.
Any cat with an untreated or poorly managed life threatening illness may lose consciousness if disease is advanced.
In addition to medical history and physical exam, diagnostics for coma or syncope include:
Some diagnostics may require referral to a specialist.
Treatment varies widely depending on the underlying cause of syncope or coma. Once a basic cause of syncope or coma is identified, supportive care measures to stabilize cats while further diagnostics occur include:
During syncope, the forelimbs may briefly become rigid and the head may be pulled back, causing confusion with a seizure disorder (such as epilepsy). In syncope, any movement is brief, whereas seizure disorders usually involve a lot of movement.
Loss of consciousness may be mistaken for very deep sleeping, especially in old or deaf cats. It also may be mistaken for collapse: cats that collapse still respond to stimuli.