What is hantavirus?
Hantavirus is a disease caused by hantavirus pulmonary syndrome virus (HPSV), a rodent-borne virus from the family Bunyaviridae [1]. The disease is characterized by flu-like symptoms and is spread through rodent droppings, saliva, or urine. HPSV can cause hantavirus pulmonary syndrome (HPS), a severe and sometimes fatal respiratory disease in humans [2].
Hantaviruses are found throughout North, Central, and South America, especially in rural areas where rodents live. Different hantavirus strains can be carried by different rodent species. In the United States, the deer mouse is the primary carrier of hantavirus strains that can cause HPS [1].
How do humans get infected?
The main way humans get infected with hantavirus is by inhaling aerosolized virus particles from the urine, saliva, or droppings of infected rodents. This typically happens when cleaning or occupying closed spaces where rodents actively nest or burrow. Disturbing rodent nests, burrows, urine, droppings, or materials contaminated by their saliva or urine can stir up and aerosolize virus particles that can be inhaled if proper precautions aren’t taken.
According to the CDC, outbreaks of hantavirus infections have occurred when people entered or cleaned rarely used cabins, barns, sheds, and other outbuildings that were rodent infested (CDC, 2023). Breathing in the virus can cause hantavirus pulmonary syndrome (HPS), a severe and sometimes fatal respiratory disease in humans.
Where is hantavirus found?
Hantavirus is predominantly found in rural areas of the Americas and Asia. In the Americas, hantavirus is found through most of North and South America, though it is most common in rural areas of the western United States. Specifically, the virus is often found in rodent populations living in the Four Corners region of the American Southwest. Hantavirus is also present across much of South America, especially in rural portions of Argentina, Chile, Brazil, Paraguay, Bolivia, and Panama.
In Asia, hantaviruses are found across a wide region including China, the Korean Peninsula, and Russia. Rural areas of India and Pakistan also harbor hantaviruses. The specific types of hantaviruses present vary by region, as different rodent species carry different strains. But overall, rural communities near forests or fields provide the ideal rodent habitat for hantaviruses to persist.
What animals carry hantavirus?
In the United States, the primary carrier of hantavirus is the deer mouse (Peromyscus maniculatus). Deer mice are found throughout most of North America, and the strains of hantavirus they carry are called Sin Nombre virus and related viruses [1]. Other species of mice, rats, voles, and even shrews have been known to carry hantaviruses in other parts of the world. Each region tends to have a predominant rodent carrier that harbors a local variant of hantavirus [2].
Can dogs get infected?
It is extremely rare, but possible for dogs to become infected with hantavirus. According to the CDC, dogs and cats do not carry hantavirus. However, they can become infected through close contact with infected rodents that carry the virus.
For a dog to get hantavirus, they would need exposure to fresh urine, droppings, or saliva from infected rodents. The main way this could happen is if an infected rodent bites a dog while being caught or carried. Dogs may also become infected by eating infected rodents. But simply being around rodents is not enough for a dog to get hantavirus.
While rare, there have been some reported cases of dogs becoming infected. A 2010 study found antibodies for Sin Nombre virus, the hantavirus strain in North America, in dogs that lived on Native American reservations with known outbreaks. This suggests dogs can contract the virus through close rodent exposure. But infection appears limited and non-contagious between dogs.[1]
How would a dog get infected?
Though dogs cannot actually get sick from hantavirus, they can become carriers of the virus through exposure to infected rodents. The main ways a dog could get infected include:
Exposure to infected rodent urine, saliva, or droppings – If a dog comes into contact with the bodily fluids or excretions of infected rodents, they can pick up the virus. This often happens when dogs explore areas inhabited by rodents like woods, barns, crawl spaces, or unmaintained storage areas.[1]
Biting or killing infected rodents – Dogs have a natural instinct to hunt rodents. If a dog kills or consumes an infected rodent, the virus can spread to the dog through bites or contact with the rodent’s bodily fluids.[2]
While a dog infected with hantavirus will not get sick, it can potentially spread the virus by tracking rodent droppings or saliva indoors through its fur and paws. Proper hygiene for dogs that go outdoors can help prevent disease transmission.
[1] https://www.cdc.gov/hantavirus/hps/transmission.html
[2] https://doh.wa.gov/you-and-your-family/illness-and-disease-z/hantavirus
What are the symptoms in dogs?
The symptoms of hantavirus infection in dogs can include:
Fever – Dogs with hantavirus may develop a high fever, often over 104°F. The fever can come on suddenly and may last for several days. According to the NYC Department of Health, fever is a common sign of hantavirus infection in dogs that can last for weeks (1).
Lethargy – Infected dogs tend to become very lethargic and have little energy. They may be reluctant to move around or play.
Vomiting – Vomiting is another common symptom, especially in the early stages of the disease. Dogs may vomit repeatedly over the first few days of illness.
Diarrhea – Some dogs with hantavirus develop diarrhea in addition to vomiting. The diarrhea can range from mild to severe.
Respiratory distress – More severely affected dogs may have difficulty breathing. Fluid can build up in the lungs, causing respiratory distress similar to pneumonia. Dogs may cough, wheeze or seem short of breath (2).
The symptoms tend to come on quite suddenly within 1-2 weeks after exposure to the virus. Dog owners should monitor for these signs if their dog may have been exposed to rodents or their droppings.
(1) https://www.nyc.gov/assets/doh/downloads/pdf/zoo/lepto-owners.pdf
(2) https://wagwalking.com/wellness/can-dogs-get-hantavirus
Is there a vaccine?
Currently, there is no FDA-approved vaccine for hantavirus infections in humans or dogs (https://www.cdc.gov/hantavirus/hps/diagnosis.html). Despite ongoing research and development efforts, no hantavirus vaccine has successfully made it through clinical trials and the approval process. This is largely due to the complex nature of hantaviruses and challenges in stimulating protective immunity across the many hantavirus subtypes (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002362/).
While some experimental hantavirus vaccines have shown promise in animal models, none have demonstrated sufficient efficacy for wide use in humans yet (https://en.wikipedia.org/wiki/Hantavirus_vaccine). There are also no veterinary hantavirus vaccines available for dogs.
Without a vaccine, the most effective prevention is controlling rodent populations that can transmit hantavirus infections. Keeping rodents out of homes and workplaces through sanitation, exclusion, and traps can reduce risk. Proper PPE should also be used when cleaning areas with rodent infestations.
How is it diagnosed and treated?
Hantavirus infection is diagnosed through blood tests that look for antibodies produced by the immune system in response to the virus. These include ELISA, immunoblot, and immunofluorescence assays. A specific diagnosis can be made within the first week after symptoms begin.
There is no vaccine or cure for hantavirus infections. Treatment focuses on managing symptoms and providing supportive care. This includes:
- Intravenous fluids and electrolytes to help maintain fluid balance.
- Supplemental oxygen for respiratory distress.
- Medications to treat hypotension and maintain adequate blood pressure.
- Mechanical ventilation in severe cases with acute respiratory distress syndrome.
- Kidney dialysis if acute kidney failure occurs.
With intensive supportive therapy, the mortality rate for HPS can be reduced to 36%. Patients who survive the acute phase typically recover with no long-term impairments.
Prevention tips for dog owners
The main way to prevent hantavirus exposure for dogs is to avoid contact with infected rodents and their droppings. Here are some tips:
Use rodent traps and exclude them from sheds, barns, and homes. Seal any openings larger than 1/4 inch to prevent entry. Remove clutter and tidy areas where rodents may nest.
When cleaning areas with rodent droppings, wear protective clothing like gloves and a mask. Ventilate the space and use disinfectant. Double bag and dispose of waste.
Use EPA approved hantavirus disinfectants in your home and kennel areas. Mop floors and disinfect dog toys regularly.
Don’t allow dogs access to areas rodents frequent like crawlspaces, sheds, unfinished basements, and garages. Supervise outdoor time.
Keep dog food in rodent-proof containers and promptly clean up any spills or waste.
Talk to your vet about repellents, vaccines, and other preventative care if rodents are common near your home. While the risk is low, it’s smart to take precautions.
While hantavirus in dogs is very rare, avoiding exposure protects both pets and people. Take steps to rodent-proof your home today.
