SALT LAKE CITY (ABC4) – Four of the five African lions at Utah’s Hogle Zoo have tested positive for COVID-19 after exhibiting symptoms, including sneezing and coughing. This comes just a few months after the zoo said it would not vaccinate its animals because officials believed they were at a low risk of contracting the virus.

The Hogle Zoo says swabs of the lions were collected voluntarily through training. Samples were sent to the National Veterinary Services Laboratory and came back positive for the COVID-19 Delta variant. Zoo officials say they do not know how the lions contracted the virus.

Before the lions tested positive, the Hogle Zoo says it established “a stringent animal care COVID-19 safety plan.” Existing protocols include increase use of PPE, regulated staff involvement, increased cleaning procedures, and staff health monitoring continues to be enforced.

“UHZ follows guidelines recommended by the Centers for Disease Control (CDC), Utah Department of Health, and the Salt Lake County Health Departments,” says Dr. Nancy Carpenter, Director of Animal Health.

Hogle Zoo recommends visitors wear masks, specifically in enclosed areas at the zoo. Zoo officials say they will continue to monitor and manage specialized animal care dictated by CDC guidelines and continues to work with many other zoos nationwide that are experiencing similar animal infections.

SLIDESHOW: African lions at Utah’s Hogle Zoo

Because there is no known risk to the public, the Hogle Zoo will keep the African lions on exhibit. There are currently no other animals at the zoo under care for symptoms of infection.

In July, the zoo confirmed it had no plans to vaccinate its animals against COVID-19 despite others doing it nationwide. Dr. Carpenter told ABC4 then that, “Due to the efforts of the animal care staff at the zoo, the veterinarians feel that our animals are at a low risk to contract this virus.”

Zoo staff, veterinary teams, and animal care teams across the organization continue to remain attentive should other animals display symptoms, and require treatment. Zoo officials say they will continue to monitor the lions’ clinical signs for worsening symptoms.

The Denver Zoo announced Monday morning that 11 of its African lions have tested positive for COVID-19. Three African lions at the Indianapolis Zoo tested positive last week after two females started showing symptoms. The third, a male lion, was asymptomatic.