Strep Zoo in Animal Care Facilities: What It Is and How to Prevent It

(Please note that some content may refer to our original name, PetAirapy.)

January 5, 2018

Lethargic Dog

It doesn’t always make the splashy headlines like dog flu or canine cough, but Streptococcus zooepidemicus, or “strep zoo” as it’s more commonly known, is deadly serious for dogs and businesses. Earlier this month, a humane society in Kentucky announced it would be closing to “clean and quarantine” for two weeks after a dog at the facility tested positive for strep zoo. To date, a reported three dogs have died at the shelter due to strep zoo. The 14-day closure meant the organization could not receive or adopt out animals at the facility during the quarantine, and a temporary shelter had to be put in place and made operational within 48 hours.

So, what exactly is strep zoo and how could it cause such a disruption?

What is strep zoo?

Streptococcus zooepidemicus is a bacterial infection that affects the respiratory system. According to, it “causes a severe, bloody pneumonia in dogs, producing signs similar to those associated with toxic-shock syndrome in humans.”

While strep zoo is more commonly known to impact horses, in 2008 reported the bacterium “kills infected shelter dogs at an alarming rate…prompting an alert to clinical practitioners who encounter densely housed animals.” In February of that year, strep zoo struck at an animal shelter near Milwaukee, killing seven dogs in 10 days. Earlier that month, “a dozen dogs died in a Miami shelter where the bacterium was identified.” In a 2014 article, VetInfo reported strep zoo “killed several dogs at Philadelphia-area animal shelters in the past year and in Brooklyn, New York, in 2009.” Also in 2014, the Royal Veterinary College at the University of London noted this stunning statistic: “In 2007 at one rehoming centre in California over a thousand dogs were estimated to have suffered or died from hemorrhagic pneumonia caused by Streptococcus zooepidemicus. In 2009 around 30 dogs a day were developing pneumonia at a kennel in South Korea.” called it “an emerging respiratory disease that can kill” in 2014. Per the online pet health resource:

“The Canine Infectious Respiratory Disease (CIRD) Group at the Royal Veterinary College (RVC) are currently researching a bacterial disease that has been increasingly implicated in fatal cases of infectious pneumonia in dogs over the past five years. They are calling for dog owners and vets to recognize the signs of the potentially fatal disease Streptococcal pneumonia to ensure rapid treatment and contribute to research to reduce further spread.”

In 2011, Dr. Cynda Crawford, Clinical Assistant Professor in Maddie’s Shelter Medicine Program at the University of Florida College of Veterinary Medicine, presented a conference session on this “emerging pathogen in shelters” causing “deadly concern.”

These above examples of the impact of strep zoo would indicate it’s only a concern for shelter animals. If you’re not familiar with strep zoo, despite that dire data from over the past decade, perhaps it’s because it has had its biggest impact on shelter animals, not making the splashy headlines like dog flu in boarding facilities and dog parks. But should others be concerned? While advises that strep zoo “is rarer in family pets” they also note that “it is still important for owners to be aware of the symptoms, especially if they regularly visit kennels or go to events where animals gather.”

How does strep zoo spread and how can it be prevented?

Strep zoo is shed in respiratory secretions. notes that “(t)he bacterium can be ‘carried’ by dogs in their upper respiratory tract (most likely their tonsils) without showing any symptoms of disease and it is likely that, as yet unknown, bacterial, host or environmental factors, possibly including an over-exuberant immune response to the bacteria, are responsible for the severe pneumonia observed in the worst cases. These ‘carrier’ dogs may be an important source of infection if introduced to new populations, especially in rehoming kennels where dog come and go all the time.”

From the May 2011 issue of The Veterinary Journal:

“Canine vaccines for S. zooepidemicus are currently not available and prevention of the disease therefore relies on limiting bacterial spread by implementing stringent control measures in kennels.”

The spread of infectious bacteria can be limited by sanitizing the surfaces and air, but the usual method of disinfecting surfaces and tools with sprays and then wiping down still allows for missing areas, possibly leaving behind microscopic microbes that may still linger on floors, countertops, and any other surface that needs regular cleaning. After normal cleaning procedures, UV technology can help optimize disinfection but – and this is a big but – it must be the right UV. The truth is you get what you pay for. “Over the counter” UV light is not strong enough and cannot achieve a high enough pathogen kill rate that’s needed to be effective. Further, you must have the right amount of UV energy. Every building has different, custom requirements. Be wary of UV “distributors” and a one size fits all sales mentality. Taking the time and working with experts matters. The risk of the spread of strep zoo, along with its potential consequences of a prolonged facility shutdown, financial loss, and the ultimate loss – life – can be reduced, but only with the proper sanitizing protocols.

Streptococcus zooepidemicus is a pathogen included in the PetAirapy UV knowledge database. We have the science-backed information on how much germicidal energy is needed to kill it and help prevent it from spreading. For more information, contact us today.

Share this story...