Possum saliva poses very little direct danger to humans. The most common fear, rabies, is nearly a non-issue with opossums, and their saliva doesn’t carry the kinds of toxins or concentrated pathogens that make bites from other wild animals especially risky. That said, any wild animal bite can introduce bacteria into a wound, and there are a few indirect disease concerns worth understanding.
Why Opossums Almost Never Carry Rabies
The Virginia opossum, the species found throughout North America, has a core body temperature between 94 and 97°F. That’s significantly lower than most mammals, and it matters because the rabies virus struggles to replicate at those temperatures. This built-in resistance makes opossums one of the least likely wild mammals to be rabid.
National rabies surveillance data backs this up. In 2023, the United States recorded 3,760 confirmed animal rabies cases. Bats led with 1,298 cases, followed by raccoons at 1,085. Virginia opossums accounted for just one single confirmed case out of all wildlife tested that year. For context, river otters, bobcats, and even black bears each had more confirmed cases than opossums did.
So if an opossum hisses at you or you notice drool around its mouth, that’s almost certainly not a sign of rabies. It’s far more likely a defensive display.
What the Drooling and Foaming Actually Means
Opossums are famous for “playing dead,” a reflex called thanatosis. When triggered, the animal collapses, goes limp, and produces heavy salivation along with urination and defecation. The foaming mouth looks alarming, and many people mistake it for a symptom of rabies, but it’s an involuntary stress response designed to convince predators the opossum is already dead and not worth eating.
This saliva isn’t toxic. It doesn’t contain venom or any specialized harmful compounds. The reaction is purely physiological, similar to how humans might sweat or feel nauseated under extreme stress.
Bacteria From Bites Are the Real Concern
Like any wild animal, an opossum’s mouth harbors bacteria. If you’re bitten and the skin is broken, the wound can become infected with common bacterial species found in animal saliva. This isn’t unique to opossums. A bite from a raccoon, squirrel, or even a domestic cat carries similar bacterial risks.
The practical concern is wound infection, not exotic disease. Clean any bite thoroughly with soap and running water, and seek medical attention. A healthcare provider will evaluate whether you need antibiotics or a tetanus booster. While the rabies risk from an opossum is extremely low, a provider may still assess the circumstances of the bite to determine if post-exposure treatment is warranted.
Diseases Opossums Carry (but Not in Their Saliva)
Opossums are linked to a few notable diseases, but the transmission routes don’t involve saliva directly.
- Equine Protozoal Myeloencephalitis (EPM): This is a serious neurological disease in horses caused by a parasite called Sarcocystis neurona. Opossums are the definitive host, meaning the parasite completes its life cycle in their intestines. Horses get infected by eating food or drinking water contaminated with opossum feces, not through saliva or direct contact. If you keep horses, keeping opossums away from feed storage and water troughs is important.
- Chagas disease: Opossums are one of the most important wild reservoirs for the parasite that causes Chagas disease. However, transmission to humans happens primarily through the feces of triatomine bugs (“kissing bugs”) that feed on infected opossums, or through contaminated food and beverages. The World Health Organization notes that outbreaks have been linked to food contaminated with opossum excrement, not saliva.
In both cases, opossum feces are the pathway, not their mouths.
Australian Possums Are a Different Story
If you’re searching from Australia, it’s worth noting that Australian possums (ringtail and brushtail possums) are entirely different animals from the North American opossum. They belong to separate taxonomic orders and carry different disease risks.
Australian possums are linked to the spread of Buruli ulcer, a skin infection caused by Mycobacterium ulcerans. CDC research has found that possum feces testing positive for this bacterium at residential properties correlated with higher rates of Buruli ulcer among residents. In some cases, contaminated feces were detected up to 39 months before human cases appeared in the same area. The transmission pathway appears to involve environmental contamination rather than direct contact with saliva, but the research underscores that Australian possums carry distinct health risks compared to their North American namesakes.
Handling an Encounter Safely
If you find an opossum on your property, give it space. They’re generally docile, non-aggressive, and will move on if left alone. An opossum that’s hissing, baring teeth, or drooling is scared, not rabid. If it’s playing dead, leave it undisturbed and it will recover and wander off on its own, usually within minutes to a few hours.
Avoid handling opossums with bare hands. Not because their saliva is especially dangerous, but because any cornered wild animal may bite, and any animal bite introduces bacteria into tissue where it doesn’t belong. Wear thick gloves if you must move one, or call your local animal control. The biggest real-world risk from opossums comes from their feces contaminating areas where pets eat, drink, or graze, not from their mouths.