Opossums very rarely get rabies, and the risk to humans is extremely low. This is largely because their unusually low body temperature—in the range of about 94 to 97°F (34–36°C)—is less suitable for the rabies virus compared with many other mammals. When people worry about opossums and rabies, they are often reacting to the animal’s scavenging habits and fearsome hissing display, but verified data show they are among the least likely species to carry and transmit rabies. Below, we break down the biology, compare risk to other common wildlife, and outline practical steps to reduce any rabies concern around opossums.
How Rabies Transmission Works
Rabies is a viral disease that spreads through the saliva of an infected animal, most commonly via bites. The virus travels from the site of the bite along nerves to the brain and central nervous system. For rabies to establish and then be present in saliva, the virus must replicate in nervous tissue and reach the salivary glands. The course of infection typically progresses through stages, including a prodromal phase, a furious phase, and finally a paralytic phase. Transmission is most likely when infectious saliva from a rabid animal comes into contact with fresh bites or mucous membranes. Because opossums seldom bite and have a low viral-shedding profile even under experimental conditions, they play a minor role in rabies transmission cycles.
Key Transmission Points
- Rabies spreads via saliva, most often through bites or mucous membrane contact.
- Infected animals must have sufficient virus in their saliva during the symptomatic phase to transmit infection.
- Opossums rarely bite and, when they do, their saliva is less likely to contain high virus levels compared with species like raccoons or bats.
Opossum Biology and Body Temperature
The Virginia opossum (Didelphis virginiana) has several physiological traits that lower its rabies risk. One of the most important is a relatively low and stable body temperature, typically between about 94 and 97°F (34–36°C). This is notably cooler than many other wild mammals, such as raccoons, skunks, or foxes. Because the rabies virus replicates more efficiently at or near typical mammalian body temperatures—around 98–104°F (37–40°C)—the opossum’s cooler physiology can limit viral growth and shedding. In practical terms, even if an opossum is exposed to rabies, the odds that the virus will establish a sufficient infection and reach transmissible levels are lower than in species with warmer bodies.
What Cooler Temperatures Mean for Infection
- Rabies virus replication is optimized at higher, near-normal mammalian temperatures.
- The opossum’s lower average body temperature creates a less supportive environment for robust viral replication.
- Field studies and surveillance data consistently show opossums are infrequently diagnosed with rabies compared with other wildlife.
Rabies Risk: Opossums Compared With Other Wildlife
From a public health perspective, rabies risk is often discussed in terms of which species are most frequently found rabid and which are most likely to transmit the virus to people and pets. In the United States, the primary wildlife reservoirs for rabies vary by region and include bats, raccoons, skunks, foxes, and, in some areas, coyotes. Opossums appear near the bottom of this list in national surveillance data. Their scavenging behavior and tendency to scavenge carrion can create the impression that they are high risk, but verified surveillance indicates otherwise. Understanding these contrasts helps place opossum risk in context and informs practical precautions.
| Attribute | Verified Detail | Source Type |
|---|---|---|
| Average body temperature | 94–97°F (34–36°C) | Veterinary/physiology references |
| Typical rabies surveillance rank | Low among common wildlife reservoirs in the U.S. | National rabies surveillance data |
| Primary rabies reservoirs in the U.S. | Bats, raccoons, skunks, foxes | CDC wildlife rabies summaries |
| Comparative risk to humans | Much lower than bats, raccoons, and skunks | Epidemiological studies |
Recognizing Rabies-Like Signs in Opossums
Although rare, any wild animal acting strangely should be treated with caution. Rabies can cause behavioral changes such as increased activity during daylight, unprovoked aggression, difficulty walking, excessive drooling, or apparent tameness. However, opossums are naturally nocturnal and may be active at night without being rabid. They are also known to "play possum," a drastic involuntary response that can include appearing weak, limp, or unresponsive, which is often confused with illness. Because of this, it is important not to interpret normal opossum behaviors as signs of rabies. If you observe a truly abnormal, aggressive, or clearly disoriented opossum—especially one that is active in broad daylight and shows neurological signs—contact local animal control or public health authorities rather than approaching it.
When to Contact Professionals
- An opossum that is actively aggressive or biting without provocation.
- Neurological signs such as circling, head tilt, paralysis, or severe disorientation.
- Repeated sightings of a sick or behaving unusually opossum in your area, which local authorities can investigate.
Preventive Measures Around Opossums
Preventing rabies exposure begins with managing attractants and securing your property. While opossums are not the primary rabies concern, reducing potential encounters is a sensible step. Secure garbage in tight-fitting containers, avoid leaving pet food outdoors overnight, and keep poultry and livestock secured. Seal gaps under sheds and decks to reduce denning opportunities. Vaccinate cats and dogs against rabies as required by law and recommended for any pets with outdoor access. These steps lower the chance of wildlife interactions and ensure domestic animals are protected even if exposure is rare.
Practical Property Management Tips
- Remove food sources such as unsecured trash and fallen fruit.
- Keep compost bins tightly closed and avoid adding meat or dairy.
- Seal potential shelter sites under structures and secure crawl spaces.
- Keep pets current on rabies vaccinations and supervise them outdoors.
What to Do If Bitten or Exposed
Rabies post-exposure prophylaxis (PEP) is highly effective when administered promptly, but it is only used when there is a credible risk of rabies transmission. If you are bitten or otherwise exposed to the saliva of a potentially rabid animal, wash the wound immediately with soap and water for at least 15 minutes. Seek medical attention right away to assess whether PEP is warranted. Public health officials can help determine risk based on the animal species, the circumstances of the exposure, and local rabies surveillance. For opossums, the likelihood that PEP is needed is very low, but any potential exposure should be evaluated by a healthcare provider or local health department.
Summary and Key Takeaways
- Opossums rarely get rabies, primarily due to their low body temperature, which limits efficient viral replication.
- They are not a primary rabies reservoir in the United States; bats, raccoons, skunks, and foxes are of greater concern.
- Strange behavior in an opossum should prompt caution and professional assessment rather than assumptions of rabies.
- Reducing attractants and keeping pets vaccinated are effective preventive measures.
- Post-exposure prophylaxis is highly effective and should be sought promptly for any credible rabies exposure risk.
If you are concerned about opossums and rabies, focus on practical prevention and rely on verified surveillance data. Opossums pose a minimal rabies risk, and informed, measured steps are the most effective way to protect both people and pets.