Observing a deer with a wet muzzle can be alarming, prompting concern about disease. While a small amount of moisture or salivation is a natural part of a deer’s life, persistent and excessive drooling, known as hypersalivation, is almost always a signal that something is wrong. Distinguishing between a temporary wet chin and a true sign of illness is important for wildlife safety and peace of mind.
Normal Salivation in Healthy Deer
Deer are ruminants, an order of mammals that includes cattle and goats, which means they possess a specialized digestive system. This process requires a significant amount of saliva to function correctly. Deer produce large quantities of saliva, which acts as a lubricant for swallowing and as a powerful natural buffer to neutralize acid production in the rumen, their first stomach compartment.
The process of “chewing the cud,” or rumination, involves the deer regurgitating partially digested plant material, re-chewing it, and mixing it with more saliva before swallowing it again. This action ensures the food particles are small enough for microbial fermentation and maintains the proper pH balance in the stomach. A healthy deer typically swallows this fluid, so excessive drooling is not normally observed.
Behavioral and Environmental Causes of Wet Muzzles
Seeing a wet muzzle on a deer does not automatically mean the animal is sick; several natural behaviors can cause temporary moisture. For instance, drinking from a pond or stream will naturally leave the muzzle and chin wet afterward. Similarly, feeding on dew-covered or rain-soaked vegetation can leave the deer’s mouth and lower face damp.
Deer may also exhibit a wet mouth due to heavy breathing or panting after a burst of activity, such as running from a perceived threat. During the rut, male deer often engage in “flehmen,” curling back their upper lip to draw in scents, which can cause temporary wetness. These instances of moisture are transient and should not be confused with the continuous, excessive drooling seen in sick animals.
Signs That Drooling Is a Symptom of Disease
Persistent or excessive drooling, where saliva visibly hangs or streams from the mouth, indicates a deer is unable to swallow, often due to a neurological issue or painful oral lesions. Hypersalivation is a symptom of several serious wildlife diseases. The inability to swallow, combined with other behavioral changes, helps differentiate a sick deer from a healthy one.
Chronic Wasting Disease (CWD) is a neurological disorder caused by an infectious protein called a prion, and excessive drooling is one of its established signs. A deer with CWD exhibits progressive symptoms like extreme weight loss, often called “wasting,” lack of coordination, and a loss of fear of humans. Drooping ears and increased drinking and urination are also commonly observed.
Epizootic Hemorrhagic Disease (EHD) is a viral disease transmitted by biting midges, or “no-see-ums,” that causes excessive salivation. EHD often appears during late summer and early fall, marked by fever, weakness, and pronounced swelling of the head, neck, and tongue. The drooling is linked to painful ulcers on the tongue and mouth, which make swallowing difficult.
Excessive drooling, along with other neurological signs, can also suggest Rabies, although this is less common in deer than in other mammals. A deer infected with Rabies may show behavioral abnormalities like disorientation, aggression, or unusual tameness. Persistent drooling is a red flag, indicating a breakdown in normal bodily function, particularly the ability to manage saliva.
Safety Guidelines for Observing Sick Wildlife
If a deer is observed with excessive, persistent drooling or other severe symptoms like listlessness, uncoordinated movement, or lack of fear, maintaining a safe distance is the most important step. Never attempt to approach, handle, or feed an animal that appears sick or injured, as this can be dangerous. Wild animals may lash out when they feel threatened, even when they are weak.
The proper response is to contact your state or local wildlife management agency, such as the Department of Natural Resources or the Game Commission. These professionals are equipped to assess the situation and determine the appropriate course of action. Providing a specific location and a detailed description of the deer’s appearance and behavior is helpful for the authorities.