SAN MARCOS, Texas (KXAN) — Cats are getting sick in San Marcos and it’s having an effect on adoption efforts at the San Marcos Animal Shelter.

The shelter announced it was suspending cat adoptions due to Feline calicivirus. The shelter says only one cat has tested positive for the virus.

Since last Thursday, however, six cats have died.

One of the cats that died was the one that tested positive and the other five cats that died were showing symptoms of the virus. But the shelter states they have not received the test results for those five cats.

“The virus presents itself as an infection and usually it starts with some eye drainage and ulcers on the tongue or the nose of cat,” says Erin McCann, representing the animal shelter.

The virus has also been described to work similar to that of the flu in humans. It’s airborne and can transfer via cats that will never show the symptoms of the virus. Because of this, the cat adoption area is closed off for one week.

In June, the shelter lost 44 cats due to the Feline Panleukopenia, which triggered a massive top-to-bottom disinfection effort for most of the facility.

Feline calicivirus not deadly, however.

“The testing process to screen for the calicivirus is extensive and has to be sent out and takes three days to get back, so that’s not something that we screen for,” says McCann.

KXAN talked to veterinarians in New Braunfels and Austin and were told that an uptick in the calicivirus is common for this time of year as most cats tend to deliver their litters in the peak of summer.

In the meantime, the shelter holds free spay and neuter clinics.

For more information on that, click here.