(CNN) -- A nurse's aide in Spain catches Ebola; her dog is taken away and put to death.

A nurse in Texas catches Ebola; her dog is fed, taken away and put into quarantine.

The stark difference in treatment illustrates the lack of solid protocol on what to do with Ebola victims' pets -- and highlights what little is known about the risk.

Why are we even talking about this?

Focusing on the cases of two dogs can seem trivial compared to the 4,000 people in West Africa who have died from Ebola this year.

But CNN's Anderson Cooper notes that concern about animals can have a broader impact on human health.

"We've seen this in disasters before, people not wanting to leave their homes because they couldn't bring their animals to a shelter," he said.

"The fear among health care workers and CDC officials and others is that if people are afraid that their dogs are going to be killed, they might not come forward if they're starting to show some symptoms."

So, can pets get or spread Ebola?

"At this time, there have been no reports of dogs or cats becoming sick with Ebola or of being able to spread Ebola to people or other animals," the Centers for Disease Control and Prevention says.

Some studies have shown that dogs may experience asymptomatic Ebola infections, the CDC says -- meaning they may have the virus but don't get sick.

Also, the agency says, human infections haven't been linked to dogs.

"The risk activities that lead to human infections are direct contact with infected human body fluids, or through bats or consumption of infected wild meat."

But it's not yet clear whether a pet's body, paws or fur can pick up and spread Ebola to people or other animals.

Biology professor David Sanders said some animals, like fruit bats, can carry the virus without showing any symptoms and could infect others.

"The concept that viruses in animals can be transmitted to humans and can have potential harmful consequences, that's obvious," said Sanders who teaches at Purdue University.

"So infected animals that are not showing signs of infection can potentially be capable of transferring virus to humans."

Do we really need to worry about pets getting Ebola?

Not at all, said Dr. William Schaffner, chair of preventative medicine at Vanderbilt University.

"It is not a danger. We're not concerned," Schaffner told CNN's State of the Union with Candy Crowley.

"We know that this virus can circulate in animals, but pets have not been a feature of Ebola spread, whether in Africa and certainly not here in the developed world," he said.

"We all thought that the attention in Spain to the dog of the person who was ill was ill-advised and was a distraction."

So why did the dog in Spain have to die?

More than 400,000 people signed an online petition asking Spanish authorities to spare the life of Excalibur, the dog of nursing aide Teresa Romero Ramos. Romero is in critical condition after helping treat an infected Spanish missionary.

But Madrid health authorities insisted they had to euthanize Excalibur in case the canine had Ebola.

Critics said the dog should have been quarantined, just like Romero's husband has been.

What about the nurse's dog in Texas?

Bentley, the dog belonging to infected Texas nurse Nina Pham, is now safe with Dallas Animal Services and Adoption Center and was taken Tuesday to Hensley Field, a decommissioned Naval Air base that's now owned by the city.

He'll be monitored at the former military complex where he's been given bedding and toys to keep him comfortable.

"Bentley is in a safe place, away from hoomes, apartments and other animals," the City of Dallas said.

More than a nurse: Who is Ebola patient Nina Pham?

Dallas city officials have posted frequently on each step of Bentley's rescue from Pham's apartment.

City spokeswoman Sana Syed said the dog is "in good hands now."

How long will Bentley have to be quarantined?

The City of Dallas said Tuesday the dog would be monitored for the next 21 days.

"The problem is we haven't really studied the progress of Ebola in dogs," Sanders said.

"What's necessary is observation, detection and quarantine until we're sure that the dog is no longer infected."

Will there be more information?

Yes -- but we don't know when.

With so many answers still unknown, the CDC says it is working with the U.S. Department of Agriculture, the American Veterinary Medical Association and other partners to develop additional guidance for the U.S. pet population.

That information will be released "as soon as it becomes available."

CNN's Sarah Aarthun and Jason Morris contributed to this report.