The North American raccoon (Procyon lotor) is a highly adaptable mammal frequently encountered in both urban and natural environments. Like all mammals, raccoons possess a specialized system of glands dedicated to producing and secreting saliva into the oral cavity. These salivary glands support their omnivorous diet and general health. Understanding the anatomy and function of this system is important, particularly in the context of disease transmission.
Raccoon Salivary Gland Anatomy
Raccoons have several pairs of major salivary glands that mirror the structure found in most other carnivorous mammals. These glands are distinct masses of tissue located around the head and jaw, responsible for producing the majority of saliva.
The largest is the parotid gland, an irregularly triangular structure situated near the ear and extending toward the masseter muscle in the cheek region. The mandibular gland, also known as the submandibular gland, is typically rounded and located near the angle of the jaw.
The sublingual gland is often divided into two parts, positioned beneath the tongue and extending into the floor of the mouth. Raccoons also possess a small pair of zygomatic glands, situated near the eye socket. These glands work together to produce a complex fluid that is secreted into the mouth through a network of ducts.
Role in Digestion and Hydration
The primary function of the saliva produced by these glands is to prepare food for the digestive tract. Saliva acts as a lubricant, moistening the food and binding it into a cohesive mass known as a bolus, which facilitates easier swallowing. The watery nature of the saliva also helps keep the oral mucosa moist, playing a role in hydration and general oral health.
Chemical digestion begins in the mouth, as the saliva contains enzymes that start the breakdown of starches. This enzymatic action is initiated as the food prompts the salivary glands. The saliva also contains immunoglobulins and other compounds that help maintain the cleanliness of the mouth and protect against pathogens.
Saliva and Rabies Transmission
The salivary glands become a site of concern due to their role in the transmission of the rabies virus, a fatal zoonotic disease. Raccoons are a major reservoir for a specific variant of the rabies virus in the eastern United States. The virus travels to the salivary glands after infecting the central nervous system (CNS).
Following a bite from a rabid animal, the virus travels along the peripheral nerves to the brain, where it replicates rapidly and causes neurological symptoms. From the infected CNS, the virus utilizes anterograde axoplasmic flow to move along the nerves. This pathway directs the virus to non-nervous tissues, including the secretory cells of the salivary glands.
Once the glandular cells are infected, the virus is shed into the saliva, making the animal infectious. Transmission to another host, whether human or pet, typically occurs when this infectious saliva enters a break in the skin, most commonly through a bite or a scratch contaminated by the animal’s saliva.
Preventing Contact and Exposure
Given the risk of rabies and other pathogens shed through saliva, avoiding direct contact with raccoons is the most effective safety measure. Never attempt to feed, pet, or handle a raccoon, even if it appears friendly or injured. Only trained wildlife professionals who have received pre-exposure vaccinations should interact with the animals.
To prevent raccoons from being drawn to human habitation, securing all potential food sources is highly recommended. This includes keeping pet food indoors and ensuring that garbage cans are fitted with animal-proof lids. Any pet that has been bitten or scratched by a raccoon must be reported to animal control and taken to a veterinarian immediately.
Ensuring that all domestic pets, especially dogs and cats, have up-to-date rabies vaccinations is a necessary layer of protection. Vaccination creates a barrier that prevents the spread of the virus from wildlife to pets and, subsequently, to people. If an animal exhibits abnormal behavior, such as staggering, uncharacteristic aggression, or a loss of fear of humans, it may be a sign of illness, and a safe distance should be maintained.