What Is Streptococcus Zooepidemicus and Why Should Rescues Be Alarmed?

In rescue and sheltering, infectious disease is always a risk. Most of us are used to managing upper respiratory infections or mild cases of kennel cough. But sometimes, something far more dangerous enters the picture. Something fast-moving, deadly, and hard to stop.

Recently, a rescue had a transport that led to the accidental exposure of several dogs to a highly contagious bacterium: Streptococcus equisubsp. zooepidemicus, also known as Strep zoo. Within days, the outbreak had infected more than two dozen dogs, claimed multiple lives, and forced every animal in the rescue into medical treatment. Staff members also became ill, and the facility had to shut down completely.

Strep Zoo is not just another cold! It is a fatal and fast-moving respiratory crisis.

What is Streptococcus zooepidemicus

Strep zoo is a bacterial pathogen that lives harmlessly in horses but becomes extremely dangerous in dogs. Although not a new bacterium, it is now considered an emerging threat in animal shelters, boarding facilities, and rescues because of how quickly and lethally it spreads.

It can be transmitted through the air, through direct dog-to-dog contact, or contaminated objects such as water bowls, toys, leashes, bedding, and even human hands and clothing. Once it enters a facility, it can infect an entire kennel in a matter of days.

Why Is It So Dangerous

Strep zoo is not kennel cough. It is more aggressive, faster, and often fatal.

• Rapid onset: Dogs can go from coughing to death in 24 to 48 hours

• Hemorrhagic pneumonia: The most severe form causes bleeding into the lungs and often results in sudden death

• No vaccine: There is currently no vaccine to prevent Strep zoo in dogs

• Zoonotic risk: Although rare, this disease can spread to humans, especially people with weakened immune systems

Because symptoms often start mild, dogs may not receive medical treatment until it is too late.

Symptoms in Dogs

Strep zoo can mimic upper respiratory infections in the beginning, which makes it difficult to detect early. It progresses quickly.

Early signs may include:

• Mild cough or sneezing

• Nasal or eye discharge

• Lethargy

• Loss of appetite

• Low to moderate fever

Advanced symptoms include:

• High fever

• Labored breathing

• Bloody cough or nasal discharge

• Sudden collapse

• Death within hours of symptom onset

Immediate veterinary care is critical. If you suspect a dog has been exposed, do not wait.

Can Humans Catch It

Yes, but it is rare. Strep zoo is considered zoonotic, meaning it can be transmitted from animals to humans. While the risk is low, it has been documented in people who are immunocompromised or who have had significant exposure to infected animals or surfaces.

In humans, it has been linked to:

• Pneumonia

• Sepsis

• Meningitis

During an outbreak, it is essential to follow strict biosecurity measures, including the use of gloves, masks, gowns, and proper handwashing protocols.

How It Spreads

Strep zoo spreads easily and in multiple ways:

The bacterium can survive on surfaces for extended periods, which is why thorough disinfection is essential. Use properly diluted bleach (1:32) and remove all soft materials that cannot be sanitized.

What Shelters and Rescues Should Do

If there is any suspected or confirmed case of Strep zoo, immediate containment is necessary.

• Quarantine all exposed animals

• Begin broad-spectrum antibiotics under veterinary supervision

• Use full PPE for all staff handling animals

• Disinfect all surfaces multiple times per day

• Stop all intake and adoptions until cleared

• Do not share any equipment or supplies between dogs

The key to survival is early intervention and strict infection control.

Lessons for the Broader Community

Outbreaks like this are a stark reminder of the vulnerability of shelters and rescues. Most facilities operate on razor-thin budgets and rely on volunteers, fosters, and public support. An outbreak like this does not just threaten animal lives. It halts adoptions, drains resources, and leaves every dog at risk.

Here is how you can help if a rescue is experiencing a Strep zoo outbreak:

• Respect temporary closures, quarantines, and intake suspensions

• Donate funds or critical supplies like PPE, thermometers, antibiotics, and disinfectants

• Share educational resources to raise awareness

• Offer to foster once the animals are medically cleared

Additional Reading

For those who want to learn more about Strep zoo, here are some credible sources:

• Merck Veterinary Manual: Streptococcus zooepidemicus in Dogs

• Cornell University College of Veterinary Medicine: Hemorrhagic Pneumonia Outbreaks

• CDC: Zoonotic Streptococcal Infections

Final Thoughts

Streptococcus zooepidemicus is not just another respiratory bug. It is a fast-acting, high-risk emergency that can decimate an entire rescue or shelter in days.

Understanding the risk, the symptoms, and the urgency of early intervention is the first step toward protecting the animals in our care and the people working to save them. Let this be a wake-up call and not a death toll.