Hendra Virus in Grand Rapids, Michigan: What Horse Owners Need to Know

Hendra virus is a rare but serious zoonotic disease, meaning it can spread from animals to humans. It is primarily transmitted from infected horses to people through close contact with the horse’s body fluids.

While Hendra virus cases have mainly been reported in Australia, it is of interest to public health and veterinary professionals in the United States, including Michigan, because similar bat–horse–human transmission patterns could occur with related viruses. Horse owners in the Grand Rapids area should understand the risks, symptoms, and prevention strategies, especially given Michigan’s active equine community and the presence of bats in West Michigan.

Important: To date, there have been no confirmed animal or human cases of Hendra virus in Michigan, including Grand Rapids.

Is Hendra Virus a Risk in Grand Rapids, MI?

  • Hendra virus itself has not been detected in horses or humans in Michigan.

  • However, fruit bats (flying foxes) are known reservoirs in other countries, and bats in general are common across the Great Lakes region, including Kent County.

  • Because Grand Rapids has:

    • A significant number of recreational and competitive horses,
    • Rural and suburban properties where horses and wildlife mix,
    • Four distinct seasons (with horses often stabled indoors during cold, wet winters),

    local veterinarians and public health officials monitor emerging zoonotic diseases closely.

If you own or work with horses around Grand Rapids, staying informed and practicing good biosecurity helps protect both animals and people from a range of infections, including Hendra-like viruses.

No Human Cure, Vaccine, or Specific Treatment

Currently, there is:

  • No cure for Hendra virus in humans
  • No human vaccine
  • No specific antiviral treatment

Medical care focuses on:

  • Supporting breathing and circulation
  • Treating complications such as severe lung infection or brain inflammation
  • Intensive care support (including mechanical ventilation) if needed

A vaccine for horses (used in countries where Hendra is present) has been available since 2012. While this specific vaccine is not routinely used in Michigan, the concept highlights how vaccinating horses can be a frontline defense in regions where the virus circulates.

How Hendra Virus Spreads

In areas where Hendra virus exists, the infection cycle typically looks like this:

  1. Fruit bats (flying foxes) are the natural reservoir. They carry the virus without appearing sick and excrete it in:

    • Urine
    • Feces
    • Saliva

  2. Horses are infected when they:

    • Eat pasture or fruit contaminated with infected bat urine, droppings, or saliva
    • Ingest or inhale virus particles from contaminated surfaces or feed/water

  3. Humans are infected through close contact with an infected horse, particularly:

    • Blood
    • Urine
    • Saliva
    • Nasal secretions
    • Other body fluids

People at increased risk include:

  • Horse owners and trainers
  • Stud workers
  • Veterinarians and veterinary assistants
  • Farriers
  • Equine dentists
  • Stable hands and strappers
  • Feed delivery workers and others with frequent close horse contact

Person-to-Person Spread

Evidence to date indicates that Hendra virus does not spread from person to person. Infection occurs through direct exposure to infected horses, not casual contact with other people.

Symptoms of Hendra Virus in Horses

Infected horses can show vague, non-specific signs that may resemble other common illnesses. This makes professional veterinary assessment critical.

Possible symptoms in horses include:

  • Frothy nasal discharge or mucus
  • High fever
  • Rapid heart rate
  • Difficulty or rapid breathing
  • Excessive sweating
  • Muscle spasms or twitching
  • Muscle weakness
  • Problems with balance, such as:
    • Uncoordinated gait
    • Head tilt
  • Apparent vision loss
  • Aimless or abnormal walking
  • Rapid deterioration and collapse

In West Michigan’s cold fall and winter seasons, respiratory signs in horses are common from other causes (e.g., influenza, bacterial infections). Because symptoms can overlap, never assume it’s “just a cold”—contact your veterinarian promptly if your horse is acutely unwell.

If you suspect Hendra virus (for example, if you have recently imported horses or been in contact with horses from affected regions overseas), avoid close contact and isolate the horse until a veterinarian can evaluate it.

Symptoms of Hendra Virus in Humans

Hendra virus tends to affect either the respiratory system (lungs) or the nervous system (brain).

Symptoms in people can include:

  • Fever
  • Headache
  • Dry cough
  • Sore throat
  • Shortness of breath or difficulty breathing
  • Dizziness
  • Unusual sleepiness or extreme fatigue
  • Confusion or changes in mental state

Possible Complications

Without prompt medical care, Hendra virus can lead to:

  • Septic pneumonia
    • Severe lung infection with pus, abscesses, and destruction of lung tissue
  • Encephalitis
    • Inflammation and swelling of the brain
    • Can cause convulsions, coma, and may be fatal

The incubation period (time from exposure to symptoms) is usually 5 to 16 days, and can be up to 21 days.

If you live in the Grand Rapids area and develop these symptoms after close contact with a very sick horse, seek urgent medical care at:

  • Spectrum Health hospitals and clinics
  • Trinity Health Grand Rapids
  • University of Michigan Health–West (Metro Health)
  • Mercy Health facilities in West Michigan

Tell the healthcare team about your recent horse exposure and any travel or importation history related to horses.

Diagnosis of Hendra Virus

Because Hendra virus is rare and not currently present in Michigan, it would be considered only in very specific high‑risk situations, such as:

  • Recent close contact with an imported horse from an affected region
  • Occupational exposure in a research or quarantine facility

Diagnostic steps may include:

  • Detailed medical history, including:
    • Degree and type of contact with horses
    • Travel or importation history
    • Occupational exposures
  • Physical examination
  • Blood tests and other laboratory testing
  • Coordination with state and federal public health and veterinary authorities for specialized testing if Hendra virus is suspected

In horses, veterinarians work with state agriculture and animal health authorities to collect and submit appropriate samples for testing.

Treatment and Hospital Care

There is no specific antiviral medication for Hendra virus. Treatment focuses on:

  • Hospital admission and close monitoring
  • Intravenous (IV) fluids and medications to support blood pressure and manage symptoms
  • Respiratory support, including:
    • Supplemental oxygen
    • Mechanical ventilation (life support) if necessary
  • Management of complications such as pneumonia or encephalitis in an intensive care setting

In Grand Rapids, serious suspected or confirmed cases would typically be managed in major hospitals such as Spectrum Health or Trinity Health Grand Rapids, with support from infectious disease specialists and the Michigan Department of Health and Human Services (MDHHS).

Outbreak Control and Public Health Response

Because Hendra virus is a serious emerging infection, one confirmed human case is treated as an outbreak.

If a case were ever suspected in Michigan:

  • MDHHS, the Kent County Health Department, and Grand Rapids Public Health would coordinate with:
    • State agriculture and animal health agencies
    • Federal partners (e.g., CDC, USDA)
  • Public health actions could include:
    • Tracing and monitoring close contacts
    • Testing and quarantining exposed horses
    • Biosecurity and cleaning measures at affected properties
    • Public information and guidance for horse owners and veterinary professionals

Best Protection: Good Hygiene and Safe Horse Handling

Even though Hendra virus has not been found in Michigan, the same precautions that protect against Hendra also reduce the risk of many other infections that can pass between horses and humans.

Everyday Hygiene Practices

  • Wash hands thoroughly with soap and water:
    • After handling horses
    • After contact with horse equipment, tack, or bedding
    • Before eating, drinking, or touching your face
  • Dry hands completely with a clean towel or air dryer.
  • Avoid touching your eyes, nose, or mouth with unwashed hands.

Handling Sick Horses

If a horse is sick:

  1. Isolate the horse from other animals as much as possible.
  2. Limit the number of people who handle the sick horse.
  3. Contact your veterinarian immediately for advice and examination.

When you must handle a sick horse:

  • Wear disposable gloves.
  • Wear goggles or a face shield if splashes of blood or body fluids are possible.
  • Wear long sleeves and long pants; consider a waterproof apron or coveralls if heavy contamination is likely.
  • After contact:
    • Remove and dispose of gloves safely.
    • Wash hands immediately after removing gloves.
    • Shower and change clothes as soon as possible if your clothing is contaminated.
    • Wash contaminated clothing in a normal laundry cycle before re-use.

Avoid contact with:

  • Blood
  • Urine
  • Saliva
  • Nasal secretions
  • Feces

Even if a horse has died, do not handle the body without protective gear, as virus in body fluids may still be active.

Avoid High-Risk Behaviors

  • Do not kiss horses on the muzzle, nose, or face.
  • If you come into contact with horse secretions, wash the area thoroughly with soap and water and dry well.

Reducing Risk on Your Property in West Michigan

To lower the risk of horse exposure to bat-borne infections:

  • Do not place feed or water troughs:
    • Under trees where bats or other wildlife may roost
    • In areas where fruit from overhanging trees can drop into troughs
  • Clean up fallen fruit near pastures or paddocks.
  • Store feed in sealed containers to prevent contamination by wildlife.
  • Work with your veterinarian on:
    • Vaccination schedules (for other common equine diseases)
    • Parasite control
    • Biosecurity plans tailored to your stable or farm

In regions where Hendra virus is present, horse vaccination is a key prevention tool. While Hendra vaccination is not routine in Michigan, staying current on all recommended equine vaccines is essential for overall herd health.

While Hendra virus has not been detected in Michigan, bats in the United States can carry other serious viruses, including rabies and related lyssaviruses.

Key points for Grand Rapids residents:

  • Never handle bats yourself, whether they appear sick or injured.
  • Bites, scratches, or exposure of broken skin or mucous membranes (eyes, nose, mouth) to bat saliva, blood, or urine can transmit rabies or similar viruses.
  • Anyone who regularly handles bats (e.g., wildlife rehabilitators, researchers) should be vaccinated against rabies.

If you find a sick or injured bat in Kent County:

  • Contact local wildlife or animal control services or the Kent County Animal Shelter for guidance.
  • For potential rabies exposures, contact:
    • Your healthcare provider
    • The Kent County Health Department
    • The Michigan Department of Health and Human Services for advice on rabies post-exposure prophylaxis.

Local Resources in Grand Rapids, MI

If you are concerned about illness in yourself or a horse:

  • For people:

    • Your primary care doctor or urgent care clinic
    • Spectrum Health, Trinity Health Grand Rapids, Metro Health (U of M Health–West), or Mercy Health facilities
    • Kent County Health Department or Grand Rapids Public Health for public health questions and reporting

  • For horses and other animals:

    • Your local veterinarian or equine specialist
    • Emergency large animal veterinary services in West Michigan
    • Michigan Department of Agriculture & Rural Development (MDARD) for animal disease reporting and guidance

Key Points for Grand Rapids Horse Owners and Caregivers

  • Hendra virus is a rare but potentially fatal infection that spreads from infected horses to humans.
  • There is no cure, human vaccine, or specific antiviral treatment; care is supportive.
  • Symptoms in horses can be subtle and non-specific, including fever, breathing problems, neurological signs, and rapid deterioration.
  • Symptoms in people include fever, cough, breathing difficulties, dizziness, confusion, and severe complications like pneumonia and encephalitis.
  • People at increased risk include horse owners, stud workers, veterinarians, farriers, equine dentists, and others who work closely with horses.
  • Good hygiene, protective equipment, and safe handling of sick horses are the best defences.
  • Hendra virus has not been reported in Michigan, but staying informed and practicing strong biosecurity protects against many equine and zoonotic diseases common in the Great Lakes region.

If you live or work with horses in the Grand Rapids area and have concerns about unusual illness in a horse or in yourself after horse exposure, contact your veterinarian and healthcare provider promptly for advice and evaluation.