Five porcupines in Bar Harbor had to be rushed to the Acadia Wildlife Center over the course of one week. All five were seen to have runny noses and seemed to have trouble breathing. Three of the porcupines died in short order, leaving scientists perplexed. When they investigated further, they saw that the virus that killed the animals in Maine had originally been found in several animals throughout Canada.

The disease that the doctors located was Skunk Adenovirus 1, otherwise known as SkAdV-1. According to the Canadian Wildlife Health Cooperative, the virus’ most common symptoms are “nasal discharge, acute pneumonia, and lethargy.” Afflicted animals can also develop lesions, including bronchopneumonia and hepatitis.

Perhaps most surprising about the disease, however, is how many different types of animals it has afflicted. It was first diagnosed in a striped skunk from Ontario in 2015. Despite being named the Skunk Adenovirus, according to the Canadian Wildlife Health Cooperative, the virus has also been diagnosed in “grey foxes… African pygmy hedgehogs, raccoons, and pygmy marmosets,” as well as porcupines.

“That is a remarkably wide array of families of animals to be infected within a four to five year period of time by a virus never seen before,” University of New Hampshire Diagnostics Lab scientist David Needle told local newspaper The Bangor Daily News.

Scientists currently have no idea how the virus spreads. This uncertainty has Maine researchers on edge, as they fear that the disease will end up ravaging the local porcupine population. Thankfully, it does not appear to kill all that are infected, as biologists say that some animals are able to fully recover from the disease. However, it appears to be particularly hostile towards porcupines for an unknown reason.

“The virus is pretty easy to see when it causes disease,” explained Needle, “and the folks that have described it in each site have been doing diagnostic pathology for a long time and wouldn’t have missed it, so it seems quite likely that this is legitimately a currently emerging disease.”

The Maine Department of Inland Fisheries and Wildlife is now working with wildlife researchers, rehabilitators and trappers to study the virus.

Porcupines are common in Maine, where they are often seen by drivers as they awkwardly waddle near wooded areas. They mostly feed in the tree canopy in winter.

The Associated Press contributed to this report.