OXFORD, Ohio (KFOR/Storyful) – What some are referring to as “Zombie deer,” is on the rise across the United States, including in 13 counties in Ohio, where video shows an Oxford police officer approaching an infected deer, which was later euthanized.

The deer showed no fear of humans, as is common in infected animals, and was also unable to walk.

There are two different conditions that affect wild deer, elk, and moose that are referred to as zombie deer.

The first, which infected the deer in the video, is called EHD, or epizootic hemorrhagic disease. It can cause slobbering, walking in circles, high fever, internal ulcers and bleeding. Some herds in the Southeast have developed immunity, while deer in Ohio and the Midwest are dying.

Another condition called zombie deer is known as CWD, or Chronic Wasting Disease, which has been found in several states, including Oklahoma in 2019, when a farmed elk in Lincoln County contracted the disease, according to the Oklahoma Department of Wildlife Conservation.

CWD creates small holes in the brain, causing a wild deer, elk, or moose to behave erratically. It can be passed from animal to animal and is always fatal. CWD is caused by a misfolded protein called a prion.

EHD is caused by a bite from a midge insect. It is not transmissible to other herd animals and is not always fatal, though EHD deaths typically subside after the first frost, when the midges die off.

In both diseases, no cases have ever been documented of animal to human transmission.