Six pet cats have tested positive for bird flu in Colorado so far this year.

DENVER — Avian influenza, commonly known as bird flu, has been detected in cattle and chickens across Colorado for months, but it has now spread to at least six domestic cats, according to the Colorado Department of Public Health and Environment (CDPHE).

One of the infected cats “has had direct links to a commercial dairy facility with confirmed infection,” two others are “indoor cats that have not had direct exposure to the virus,” and the remaining three are known to be “indoor/outdoor cats that not only hunt mice and birds but also spend time indoors with their owners,” CDPHE said.

At least three of the cats infected with avian flu were in Larimer County, according to the U.S. Department of Agriculture's Animal and Plant Health Inspection Service, while a fourth cat case was found in Adams County and a fifth in Morgan County.

Denver7 has been tracking how bird flu has spread around Colorado over the past few months.

• July 3Colorado officials say a Colorado dairy worker has been diagnosed with avian influenza, the fourth case linked to an unprecedented outbreak of highly pathogenic avian influenza among dairy cows in the U.S. Colorado health officials believe this is the first known case of avian influenza possibly jumping from mammals to humans.
• Early July, Colorado Governor Jared Polis declares disaster emergency in response to a recent outbreak of avian influenza at a commercial egg facility in Weld County.
• Mid-JulyState health officials confirm to Denver 7 that three poultry workers at a commercial egg production facility in Weld County that has been hit by an outbreak of highly pathogenic avian influenza have tested presumptively positive for avian influenza.
• July 14thHealth officials have confirmed that four poultry workers in Colorado have been diagnosed with avian flu.
• July 23Colorado has announced that it will become the first state to require testing for H5N1 on dairy farms. Denver7 has a detailed look at what this means here.I looked into it. Impact on egg prices here.
• Three poultry workers at a second egg plant in Colorado have tested positive for avian flu. State officials on July 25This brings the total number of confirmed cases in Colorado this year to 10.

Dr. May Chu, an epidemiologist at the Colorado State University of Public Health, said infected cats that spent time both outdoors and indoors could have contracted the virus from other animals.

“Cats that wander or stray outside are likely to pick up a deer mouse or some kind of food and pick something up from an infected rodent,” Dr. Chu said.

Dr. Gina Rodriguez, medical director at Evans East Animal Hospital, said the symptoms look like a common cold.

“The symptoms are vague, like lethargy, and just feeling unwell,” she said. “So sneezing, eye discharge, runny nose, coughing, etc.”

The six pet cats were first tested for rabies and then diagnosed, explained Dr. Rachel Herlihy, state epidemiologist for CDPHE.

“Rabies is known to cause neurological symptoms. In cats, they can experience loss of coordination, inability to stand, tremors and even seizures. These are the same types of neurological symptoms seen with H5N1 influenza infection,” she said.

Dr. Rodriguez said he hasn't seen or heard of any cases in the Denver area, and both Dr. Herlihy and Dr. Chu told Denver 7 that at this point, these infections are not something cat owners should panic about.

Dr Herlihy added that while these cases are rare at present, cat owners should remain vigilant, especially those who work or live near dairy farms.

There have been no reported cases of infection from infected cats to humans, she said.

“In terms of the risk to pets, we know that pets come into very close contact with humans, so it's really important to know that there have been no reported human cases linked to contact with infected cats, meaning there is no confirmed transmission from cats to humans,” she said. “However, we would urge anyone who may come into contact with a suspected infected cat to take the same precautions that we ask farm workers to take, which includes wearing PPE (personal protective equipment), masks, gloves, eye protection, etc.”