The U.S. Centers for Disease Control and Prevention tightened rabies regulations for dogs coming into the country. The new regulations, which went into effect August 1, come as the temporary suspension of importing dogs from high-risk rabies areas — instituted by the CDC in 2021 — is lifted.
“What it boils down to is that there is additional rabies verification that’s required for dogs coming into the United States from high-risk countries” with higher rates of rabies, says Kaitlyn Krebs, a veterinarian at the University of Pennsylvania. It applies to dogs coming from more than 100 countries, including Afghanistan, China, India, Israel, Russia and Zimbabwe.
“These changes are a long time coming,” Krebs says. “It’s important, from a population health standpoint, that these changes are being made, especially because it is such a huge human risk to have a dog come into the country that potentially has rabies that we don’t know about.”
Rabies is a zoonotic infectious disease, transmitting from animals to humans. In the United States, about 4,000 cases of animal rabies are reported annually, more than 90 percent of which come from wildlife such as bats, racoons, foxes and skunks (SN: 6/12/19). This represents a significant shift from the mid-1900s, when domestic animals such as dogs contributed to most rabies cases. According to the CDC, fewer than 10 human deaths from rabies are now reported in the United States each year, down from several hundred in the 1960s.
As of 2021, only five rabid dogs had been imported from high-risk countries since dog rabies was eliminated from the United States in 2007. All but one of those cases were due to fraudulent paperwork, which the new CDC regulations could address. The other was due to vaccination failure.
“The U.S. has a very low level of rabies, and because of the U.S.-mandated rabies vaccinations for dogs, we don’t often see our pet dogs come down with rabies,” Krebs says. “So, you also don’t want to bring a dog in from a high-risk country if it doesn’t have adequate rabies vaccination.”
Prior to the Aug. 1 regulations, dogs arriving in the United States that had not been to high-risk countries were only required to have a travel history and healthy appearance. All dogs that had been in a high-risk country and were under six months old, without a microchip or without a rabies vaccination history were denied entry.
Now, dogs arriving in the United States from countries the CDC has classified as lower rabies risk require one form for entry, which can be filled out by the importer and does not require rabies vaccination confirmation. Dogs being imported from high-risk countries are split into those vaccinated in the United States and those vaccinated abroad. For the former, a U.S. Department of Agriculture–certified veterinarian must fill out the forms confirming the rabies vaccination. Foreign-vaccinated dogs require forms endorsed by a government veterinarian; as previously required, the dogs also must have a microchip, appear healthy and be at least six months old at the time of entry.
Rabies, which belongs to a group of viruses called lyssaviruses, targets the body’s nervous system. After the rabies virus is transmitted — often through the saliva in a bite from an animal — “it may replicate a little bit in the muscle, but then it’s looking for nerve cells,” says Susan Moore, an infectious diseases researcher at the University of Missouri in Columbia. The virus then “enters your central nervous system … and then up through the spine and up into the brain.”
Once the rabies virus has entered the brain, it is hidden from the body’s immune system by the blood-brain barrier. With no way to fight back, this brain infection can lead to neurological issues, coma and death.
The only way to treat rabies is to receive post-exposure treatment immediately after contact with a rabid animal. Treatment involves giving the infected person antibodies to “help bridge the point between the bite and where you start vaccinating” the patient to stimulate the body’s ability to create its own antibodies, Moore says. This all must happen before the rabies virus reaches the brain — which can take between weeks and months — when the antibodies can still be effective at fighting the virus in the extremities of the body.
“Rabies is not a candidate for eradication,” says Charles Rupprecht, a rabies expert based in Lawrenceville, Ga. “We can prevent it; we can control it.” But there are still high rates of rabies in countries around the world, and the risk remains that it can be brought into the United States through infected dogs. “So, these recommendations were put in place because it’s the state of our world right now.”
Questions or comments on this article? E-mail us at feedback@sciencenews.org | Reprints FAQ
U.S. Centers for Disease Control and Prevention. Bringing a dog into the U.S.
F. Whitehill et al. Rabies in a dog imported from Azerbaijan — Pennsylvania, 2021. Morbidity and Mortality Weekly Report. Vol. 71, May 20, 2022, p. 686. doi: 10.15585/mmwr.mm7120a3.
Claire Yuan is the 2024 AAAS Mass Media Fellow at Science News. She is an undergraduate at Harvard University studying chemistry & physics and history of science.
We are at a critical time and supporting science journalism is more important than ever . Science News and our parent organization, the Society for Science, need your help to strengthen scientific literacy and ensure that important societal decisions are made with science in mind.
