UPDATE: Officials recently tested 20 dogs. 18 tested negative for distemper. Two had to be euthanized.
An animal shelter in Henderson is testing for a dangerous virus.
Now, animal advocates are worried about an outbreak.
The Animal Foundation is testing 20 dogs from its Henderson adoption center for distemper, a disease that's almost always fatal.
"They're here in isolation, we're running tests on all of them and waiting for those results," said Michelle Quigley, the Animal Foundation's director of operations. "Again, this is precautionary."
The Animal Foundation is in the middle of its investigation.
"We try to determine who is patient zero, if you will, so our team is working on that now," Quigley said. We look at shelter movement, the time they came in."
Animal advocates anxiously await the test results.
"[Distemper is] deadly," said Gina Greisen, the president of Nevada Voters for Animals. "Those are serious diseases and they are very contagious."
Those results come back in a few days and Foundation leaders are confident the dogs will be distemper-free.
Only one animal has shown symptoms and the rest have all their vaccinations.
"We have no reason to believe that this is a widespread issue right now," Quigley said. "Again, it's one isolated case."
Quigley says there were dogs that left the shelter before testing started so they're reaching out to all adopters to check on those animals for symptoms.