Ebola is raising alarm around the world, but can pets help spread the often fatal disease to humans?

Some pets may be able to carry the disease, according to the Centers for Disease Control and Prevention (CDC). However, the federal agency does not believe that animals in households currently pose any significant risk to Americans.

Ebola outbreaks occur in Africa on a fairly regular basis. Reasons for the first appearance of the disease in humans each time remains a mystery.

"However, scientists believe that the first patient becomes infected through contact with an infected animal, such as a fruit bat or primate (apes and monkeys), which is called a spillover event. Person-to-person transmission follows and can lead to large numbers of affected persons. In some past Ebola outbreaks, primates were also affected by Ebola, and multiple spillover events occurred when people touched or ate infected primates," the Centers for Disease Control and Prevention explained on its Web site.

The disease can infect humans or other primates, such as monkeys and apes, which often quickly fall dead soon after infection.

Dogs may be able to carry the disease, although they do not appear to become ill. The virus itself has not been seen in canines, although antibodies have been found in the bloodstreams of dogs who lived with human victims. There have been no reports of any cats or canines becoming sick from Ebola, even in western Africa where the disease is most prevalent.

Fruit bats in Africa are able to transmit the virus, but the CDC believes American bats are unlikely to spread the disease. Still, they recommend people to not touch or pick up bats, living or dead, mainly due to other health concerns.

Felines, including lions in Africa, may be immune from the disease, as none have ever been seen becoming sick from Ebola.

Ebola is spread through body fluids, such as blood or saliva, so there could be some risk that a pet who has come in contact with a patient could spread the virus on their paws or in mouths.

Two nurses who each became ill from the disease, one in the United States and one in Spain, were each dog owners. In Europe, the canine was put down in order to minimize risks to humans. In America, a Cavalier King Charles Spaniel belonging to Ebola patient Nina Pham is being cared for by local officials awaiting updates on the health care worker's condition.

Animals have not been shown to have played a role in the current outbreak, according to the agency.