Autonomic nervous system (ANS) is part of the nervous systems that is responsible for involuntary functions such as the contraction of smooth muscles, the heart rate, respiration, digestion, urination, salivation, perspiration, eye pupil dilation,blood pressure, intestinal contractions, glandular activity, physical arousal and so on.
The involuntary body functions, that largely occur without conscious thought, fall under ANS except for breathing which works in coordination with conscious thought.
Dysautonomia is the malfunction of autonoic nervous system. Also called Key-Gaskell Syndrome, this condition is rare but often incurable and fatal.
This rare disorder can occur in any dog without any age, gender or breed predilection although free roaming rural dogs are slightly at a higher risk of acquiring this condition.
Dogs suffering from the disease typically have dilated pupils that don't respond to light, decreased tear production, and elevated third eyelids. They may also suffer from vomiting or regurgitation due to decreased motility in the digestive tract. Other signs include photophobia (fear of light), anorexia, weight loss, dribbling urine, Straining to urinate, Loss of anal sphincter tone, Diarrhea, Constipation, Possible abdominal pain, Dyspnea (difficult breathing), Dry nose and mucous membranes, Coughing, Nasal discharge, Depression, Loss of spinal reflexes, Muscle wasting and Possible weakness.