The common human action of sneezing is a rapid, involuntary expulsion of air used to clear nasal passages of irritants. When a snake performs a similar, sudden expulsion of air, observers wonder if reptiles can “sneeze” in the mammalian sense. Due to anatomical differences, snakes do not technically sneeze but can forcefully clear their airways. This behavior, whether isolated or chronic, indicates the snake’s overall health. Understanding the mechanics of snake breathing helps distinguish a normal action from a sign of potential illness.
Understanding the Reptilian Respiratory System
The mechanism for a snake’s air expulsion differs significantly from that of a mammal because snakes lack a diaphragm. The diaphragm is the muscle sheet that generates the powerful, sudden pressure change required for a true mammalian sneeze. Without this structure, snakes rely on their intercostal muscles, located between the ribs, to expand and contract the rib cage for breathing.
Inspiration is an active process involving the contraction of these body wall muscles, while expiration is often passive. To expel air with force, a snake must rapidly contract the musculature surrounding the lungs, pushing the air out in an action that mimics a sneeze.
Air travels through the nares (nostrils) into the nasal cavity before reaching the glottis. The glottis is a small opening on the floor of the mouth, just behind the tongue, and serves as the entrance to the trachea. This highly adaptable structure can be extended out the side of the mouth while the snake consumes large prey, ensuring the airway remains open. The air then enters the snake’s single, elongated right lung.
Normal Causes for Airway Clearing
A single, abrupt expulsion of air is usually a healthy, non-pathological attempt to clear a physical obstruction from the nasal passages. This action is often observed after the snake has been drinking, as small amounts of water can be inadvertently drawn into the nostrils. The forceful puff of air effectively clears the moisture and prevents it from entering the lower respiratory tract.
Another common cause relates to the shedding cycle (ecdysis), especially when the skin around the head loosens. Residual bits of shed skin can become lodged in or around the nostrils. The snake uses an expulsive burst of air to dislodge the material, acting as a natural self-maintenance action since snakes lack limbs to physically remove debris.
The surrounding environment can also trigger this airway-clearing behavior. Temporary exposure to dust, fine substrate particles from burrowing, or strong, irritating smells can prompt an isolated air expulsion. A snake’s characteristic hiss is also a forceful, deliberate expulsion of air, but this defensive behavior should not be mistaken for a symptom of illness.
When Expulsive Behavior Signals Illness
While an occasional expulsion of air is normal, repeated or chronic expulsive behavior is often a warning sign of a serious issue, typically a Respiratory Infection (RI). This chronic condition is frequently accompanied by other symptoms indicating respiratory distress. The most common cause of RI is bacterial, often stemming from poor husbandry conditions like insufficient temperature or inappropriate humidity levels, which compromise the snake’s immune system.
Owners may notice an audible wheezing, clicking, or gurgling noise when the snake breathes, caused by mucus and secretions in the airways. Visible signs of illness include frothy discharge or bubbles appearing around the glottis, nostrils, or within the mouth. This discharge builds up because the snake has difficulty clearing secretions, as its respiratory epithelium has relatively few cilia compared to mammals.
Other behavioral indicators of a severe infection include lethargy, a loss of appetite, and open-mouth breathing, suggesting the snake is struggling to take in enough oxygen. To facilitate breathing and help drain excessive mucus, the snake may hold its head elevated for extended periods. When these chronic symptoms appear alongside repeated expulsive actions, veterinary consultation is necessary to properly diagnose and treat the underlying infection.